Saturday, February 27, 2010

Feb 27: Another Potential Storm Next Week

Tonight: Mostly Cloudy. Scattered snow showers. Low temperatures will be in the mid to upper 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Tomorrow: Mostly Cloudy. Scattered snow showers. High temperatures will be in the upper 30s to lower 40s across the area.

Tomorrow Night: Mostly Cloudy. Low temperatures will be in the mid to upper 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Monday: Partly Cloudy. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

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Yesterday's Blizzard Ending, Records Approached Or Broken

The storm that was a blizzard for parts of the area on Thursday and Friday has mainly ended, though isolated snow showers should continue through tomorrow. The highest accumulations in the area came from interior southeastern New York and northwestern New Jersey, where isolated areas reached nearly 3 feet of snow. Snow totals were still high across other parts of the area, with the highest total in the immediate suburbs of NYC coming out of Bergen and Union conties, in Northeast New Jersey, with slightly over 21 inches, and Ossining in Westchester County, NY with 25 inches of snow.

Records were also approached or broken with this storm. Central Park reported nearly 21 inches of snow, making it the 4th biggest snowstorm on record there. This snowstorm is now behind the March 1888, December 1947 and February 2006 storms in terms of snow totals.

This snowstorm also increased monthly snow totals to 36.9 inches in Central Park, and over 40 inches in parts of the area. This officially makes it the snowiest February on record, with the previous record being 27.9 inches in 1934. This also makes it the snowiest month on record, with the previous record being 30.5 inches in March 1896.

The Next Storm In Line

A storm is expected to enter the California coast, and is expected to start heading east towards the eastern United States by the early week. There is still uncertainty on whether it does affect us or if it stays to our south, however. The majority of the models take the storm to our south, with the main impacts being in Washington DC and further south. What is preventing this storm from going all the way up the coast is a storm that is expected to head towards Maine by tomorrow and Monday. That will force this storm to start heading out to sea instead of moving up the coast. If we were to see the New England storm further east, or if that storm was weaker than currently expected, then this storm might be able to trend north enough for a light-moderate snowfall from New York City to Boston, however that is still uncertain.

If the storm does end up suppressed, there are some problems that would prevent this storm from producing yet another heavy snowstorm for most of the Mid Atlantic. We do not have a source of new arctic air, so the air mass is not cold enough as it was for previous storms. The average temperatures are also warmer now in the Mid Atlantic, which are too warm for a plain snowstorm in some places. So if the storm ends up being too far south, instead of a widespread south-central Mid Atlantic snowstorm as we would've seen earlier in the winter, it would be a mainly wintry mix event, with a smaller area of snow in the northern part of the storm.

Overall, at this time, there are still uncertainties with this storm, but considering some factors that I said above, I would expect this storm to have the biggest impacts in the southern and central Mid Atlantic, with the northern Mid Atlantic and southern New England seeing some impacts from this storm but not as much as places further south.

Addition To Long Range Forecast: Warm Up Next Weekend?

After the mid week storm, the models are starting to show hints of the cold pattern in the East temporarily ending, with warmer temperatures starting to enter the area. There is still some uncertainty on this time period, though I can see how places in the Mid Atlantic get high temperatures as warm as over 60 degrees if this mild spell verifies. If it does verify, this would be the first widespread significant warm up since late January.

Thursday, February 25, 2010

Feb 25-26 Storm Updates

1:24 PM: The snow is now becoming much more scattered in its coverage area, with the sun visible in some places. As the afternoon continues, expect snow squalls to continue rotating through the area, slowly weakening. As temperatures are also rising and are above freezing in most of the area, the snow will have a hard time accumulating on paved surfaces, and in some places it may not accumulate at all.

9:35 AM: An area of generally light snow with moderate to heavy bands is currently affecting the area. Snow totals are over 10 inches across most of the area with the main exceptions being Long Island and Connecticut, with parts of northern New Jersey over 20 inches. The snow bands are slowly starting to weaken, with the result being a widespread area of light to moderate snow by later this morning. Additional accumulations of 1 to 2 inches of snow are possible by 12 PM, with locally higher amounts.

6:12 AM: After several hours of wind-blown heavy snow last night across most of the region, the northern edge of the snow band has reached Southeast New York and is moving south. While the northwestern areas might get a break from the snow for a while, there are more snow bands forming over the Long Island Sound and southern Connecticut. For the short term, these bands will likely impact New York City, southern Connecticut and Long Island, however they will not be as heavy as the snow bands that affected the area last night.

Thursday, February 26

9:40 PM: Heavier snow is now starting to make its way into parts of Northeastern New Jersey and New York City. These bands are having a hard time moving south and west, however they should be able to move more south/west through tonight. As the temperatures are dropping, the snow is no longer a wet snow in most locations, and it has higher ratios, meaning that it should accumulate faster if it does fall heavy. As winds are also increasing, expect visibility to decrease to less than 1/4 mile at times, with blowing snow also reducing visibilities.

7:32 PM: After the heavy precipitation/snow ended across parts of the area between 3-6 PM, another round of moderate to heavy precipitation is currently located over Long Island and Connecticut, and is generally moving west. For those areas that saw a break in the precipitation, expect it to resume and intensify in the next 1-2 hours. The heaviest snow should enter southeastern New York and move towards northwestern New Jersey, with moderate snow/precipitation moving into New York City and Northeast New Jersey. Central New Jersey should not get affected by these bands yet, however in a few hours that area will also start to see the snow intensify.

1:29 PM: A heavy band of precipitation is currently expanding from off the coast towards western Long Island, and north towards Albany. The current rain/snow line is approximately in western Long Island towards southeastern New York, with places south/west of that line seeing snow and north/east of that line seeing rain.

In places where rain is falling, expect moderate to heavy rain to continue falling throughout the day, with up to 1/2 to 1 inch of rain possible. Snow will begin mixing this evening in the western parts of the area currently seeing rain, and will expand eastwards. In places where it is snowing, expect to see more of the wet snow falling today, with additional accumulations through 5 PM generally between 2 and 5 inches.

Wednesday, February 24, 2010

Feb 24: Major Storm To Produce Rain And Snow

As soon as we get done with the first storm, yet another storm is expected to impact the area, however this time, there will be more snow than the previous storm. The storm is currently located off the East Coast, with precipitation extending into Virginia, eastern Maryland and southern Delaware. The precipitation is currently moving northeast.

What we have here is a storm that is going to take a very unusual track, which will result in a scenario that is very different than a typical storm. The storm is going to continue to move northeast then north while rapidly intensifying, however it is then going to start moving northwest, and then west. A typical storm would move northeast or east. As a result, this storm is going to pull in colder air from its west, that due to the counterclockwise rotation of the storm, enters the southern part of the storm. Meanwhile, the warmer air from the ocean moves onshore in New England, and gets carried into the storm's eastern and northern sides, resulting in mainly rain and a wintry mix for those areas. This is why we are looking at a scenario where it could snow in Washington DC and Philadelphia, and at the same time rain in Boston and Maine.

The storm is then going to enter land, somewhere near Long Island, then it is forecast to move west until it stalls between New York City and the Hudson Valley. As the storm stalls, much colder air will the enter the storm, with most of the areas that saw rain changing over to a wintry mix or snow, however the amount of time that it takes for this changeover to happen will be different in each place.

Storm Impacts:

The storm should produce potentially heavy snow in central and northern New Jersey, with over a foot of snow possible in these areas. The further south you go, the less the snowfall amounts will be. I am currently expecting New York City to have main snow with some mixing, with a total of 6 to 10 inches of snow, though I could raise the amounts for NE NJ and NYC slightly later tonight.

Further east, into eastern Long Island, Connecticut and Massachusetts, heavy rain is expected at first. Up to potentially 2 inches of rain may fall in some areas, with flooding possible. The rain then changes over to a mix and snow, however accumulations should be generally light in those areas.

Below is my snow map for this storm. If needed, slight adjustments could be made to the map later tonight. Some of those possible adjustments could be to shift the accumulation areas slightly east in NE NJ, Long Island and Connecticut.

Tuesday, February 23, 2010

Short Term Update

Below are some short term updates for some parts of the reigon:

Long Island: Expect rain to pick up in intensity within the next hour or two. Moderate to heavy rain should continue falling in the area.

Northern New Jersey: A band of heavy precipitation is about to move through the area. This should be mainly rain in NE NJ, a wintry mix with some snow in north central NJ, and heavy snow in NW NJ.

Central Connecticut: The dry slot is now replaced with another round of precipitation. Expect precipitation to be mainly in the form of a wintry mix with some rain possible, with snow in the higher elevations and places further north.

Feb 23: Blizzard Possible In New Jersey

Current Storm Update:

While little to no snow fell in the coastal parts of the area, more than several inches of snow fell in the interior areas. With the coastal low still intensifying, for the coast, expect heavy rain to continue through early tomorrow morning with 1 to 2 inches of rain, and for the interior, depending on the exact location, the precipitation should change over to snow or a wintry mix later tonight with additional accumulations.

Expect Wednesday to be cloudy with occasional precipitation.

Late Week Storm: Blizzard Possible For New Jersey To Maryland?

After I made my post yesterday about what my first thoughts on the late week storm are, most of the models took a rather large trend inland, with the storm now shown to track over New York City. While in a typical storm, this would spell rain for New York City and further south, this storm will be different than a typical storm in its track, and therefore it will have a different impact than most storms taking this track.

The storm currently bringing snow to Texas is expected to quickly move offshore by tomorrow. Instead of going out to sea, however, this storm should then turn north and start heading towards the Northeast while rapidly intensifying. As the storm approaches the area, it then starts to move northwest towards the coast. There is still uncertainty on where it stalls afterwards, it could be near New York City as shown by the GFS and NAM, though it could still end up further north or south than this solution.

While there is uncertainty about what the precipitation types are at first across the area, the storm should then pull colder air, changing most of the area over to snow by at least Friday. The storm also stalls in the area through Saturday, producing even more precipitation until then. As the storm should also be strong, high winds are possible across the area, causing snow drifts in places where heavy snow does fall.

Snowfall amounts are still uncertain for our area, though it is becoming increasingly likely that this storm might be yet another monster storm for someone in the central or northern Mid Atlantic, with potentially 2 or more feet of snow possible in the places that get the highest snow amounts out of this storm.

Below are my current scenario maps for this storm, of what I think the two possible scenarios are at this time. The first map represents a further south and west track, where most of the area sees a wintry mix changing over to snow by Friday, with rain to mix/snow in Long Island. The second map represents a slightly further north and east track, with mainly snow across the area, in potentially big amounts. The third possible scenario is the map that I posted yesterday, which is becoming less likely but still possible.




Monday, February 22, 2010

Quick Storm Update

It appears that the storm is starting out slightly colder than expected, with mixing reported in the northern end of the rain zone in my scenario map. How long these colder than expected conditions will continue is still uncertain, though someone that is supposed to see rain might be able to pick up a surprise 1 to 2 inch snowfall if things keep going the way they currently are.

Late Week Storm: Possible Snowstorm?

As I previously mentioned on Saturday, the models have been consistently showing a storm for the late week. At that time, my thoughts were that the worst impacts of the storm should stay to our north and east, and as of now, this still appears to be the case. While there is still uncertainty for our area, the majority of the models show as much as 2 or even 3 feet of snow in the interior Northeast and New England, as an intense storm moves northwest into the Northeast from the ocean, bringing rain to the coast and heavy snow for interior locations. This storm should also stay for a longer period of time, which increases the duration of the snow for the interior areas, which is another reason for those high snowfall amounts.

While it is becoming likely that the interior should see a major snowstorm, what happens in the southern part of the storm, also over New York City, is still uncertain. Some models such as the GFS show heavy snow with as much as nearly a foot of snow for some places, the NAM model is not as agressive and has smaller precipitation amounts, and the GGEM model stays mainly to our north and east with most of the precipitation.

I am currently thinking that other than a mix possible to start, the area changes over to snow, and while accumulations are still uncertain, they could end up from light amounts in the southern parts of the area, to potentially heavy amounts in the northern parts of the area. Below is my first scenario map, with the heaviest snow in the blue zone and lighter amounts in the light blue zones. The pink areas represent mixing to snow, and the green area is mainly rain, though they could also change over to snow at the end.

**Please note, this is only my first scenario map, and is subject to change.**

Final Forecast For Tomorrow's Storm

Below is my final forecast for this storm. I have a forecast for each part of the New York City area, along with a forecast for rainfall amounts and the snow/wintry mix accumulations. At the bottom, I also included a precipitation type map and a snow map.

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Forecast Area 1: Long Island and Connecticut

Area 1: Coastal Connecticut and Long Island

The area might start out with some mixing this evening, however as the warm air pushes into the area from the west, expect precipitation to quickly change over to rain. There might be a brief break in the rain in the morning hours tomorrow, followed by the development of the coastal low. This is also when the rain intensifies for the area, and might become heavy at times. The heavy rain continues until Tuesday night, and tapers off by at least early Wednesday morning.

Snow accumulations: Little to None
Rainfall amounts: 1 to 2 inches

Area 2: Central Connecticut

Areas of light snow will approach the area tonight, and should start to intensify a little more, with some accumulations possible. As warmer air pushes into the area, expect precipitation to change over to a wintry mix. A brief break in the precipitation is possible tomorrow afternoon, while the coastal low intensifies and pulls in some colder air. The area should then see snow in the higher elevations and a wintry mix elsewhere, which could be heavy at times. The coastal then pushes in some warmer air, which changes the lower elevations over to rain/mixing with a snow/mixing in the higher elevations. Most of the precipitation will end in Wednesday morning, with scattered precipitation through the day on Wednesday.

Snow accumulations: 2 to 5 inches
Rainfall amounts: Up to 1/2 inch in the higher elevations, 0.75 to 1.5 inches elsewhere

Area 3: Northern Connecticut

Snow should start falling in the area late tonight into early tomorrow morning, steadily intensifying. After a brief break possible in the afternoon hours, more precipitation moves into the area as the coastal low continues to develop. The precipitation will be mainly in the form of snow, though southern parts of the area and the lower elevations should see a wintry mix with some rain. After becoming heavy at times overnight, the precipitation ends on Wednesday morning to afternoon, with scattered precipitation afterwards.

Snow accumulations: 5 to 10 inches
Rainfall amounts: 0.25 to 0.5 inches in the lower elevations and southern parts of the area

Forecast Area 2: New York City, Southeastern New York, and New Jersey

Area 1: Eastern New Jersey Coast

A brief wintry mix is possible early tonight, however that should quickly change over to some rain. After a break in the precipitation tomorrow morning, another round of heavy rain starts to fall. This rain will continue through tomorrow night, and end early on Wednesday morning.

Snow accumulations: None
Rainfall amounts: 0.75 to 1.5 inches

Area 2: New York City and southern Westchester County

When precipitation starts to fall tonight, it should be in the form of either light snow or a mix. The frozen preciptation continues to fall for at most a few hours with little to no accumulation, and as warm air advances into the area, the precipitation type changes over to rain. A break in the rain is possible during tomorrow morning, followed by heavier rain as the coastal low intensifies. The rain may become heavy at times. By the late evening or overnight hours, the rain should weaken, and end by early Wednesday morning.

Snow accumulations: Little to None
Rainfall amounts: 0.80 to 1.50 inches

Area 3: Northern New Jersey

The precipitation should start on Monday evening, mainly in the form of light snow or a mix. The wintry mix should intensify, with some accumulation expected. The northwestern areas might see 2-4 inches, the north central areas with 1-3 inches, and the northeastern parts with less than an inch. The precipitation then changes over mainly to a wintry mix with some light rain. There might be a break with the rain or very light rain afterwards, followed by another round of rain during Tuesday afternoon, which should be moderate to occasionally heavy. The northwestern areas might see a longer period of a wintry mix, however rain is expected there too. The rain/mix will change over to plain snow in the northwestern parts, to a wintry mix in the north central areas, and remain as plain rain in NE NJ. By tomorrow night, the precipitation will start to taper off, and should end by early Wednesday morning.

Snow accumulations: Less than 1 inch in NE NJ, 1-4 inches in north central NJ, 3-6 inches in NW NJ
Rainfall amounts: 0.5 to 1.25 inch, highest amounts further east

Area 4: Southeastern New York (from Rockland county and slightly north/west)

Light snow should start to fall tonight. The snow might intensify a little overnight with some accumulations. As the warm air pushes into the area, the snow will change over to a wintry mix and some rain in the southern parts of the area. After a brief break in the late morning hours, another round of precipitation develops in the afternoon. This should bring snow/some mixing to the north and western parts of the area, and a wintry mix of snow/mixing/rain to the southern and eastern parts of the area. Accordingly, the highest accumulations will be in the northwestern parts of the area, with 3 to 6 inches of snow, with the lowest accumulations in the southern and eastern areas, with 1 to 3 inches of snow. The precipitation should end early Wednesday morning.

Snow accumulations: 1 to 3 inches further SE, 3 to 6 inches further NW
Rainfall amounts: Up to 1/2 inch

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Storm Scenario Map (main precipitation type):



Snow Accumulation Map:

Previous Forecast Verifications

Verification For Saturday: I expected Mostly Sunny skies, with high temperatures in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast. The forecast was correct.
Score: 4/4

Verification For Saturday Night: I expected Mostly Cloudy skies, with low temperatures in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast. The temperatures did end up being slightly colder than I expected, but not much colder.
Score: 3/4

Verification For Sunday: I expected Partly Cloudy skies, with high temperatures in the lower 40s north and west of NYC, and in the mid 40s for NYC and closer to the coast. Parts of NYC reached the upper 40s, with 50 degrees even reported in Newark, otherwise the forecast was correct.
Score: 3/4

Verification For Sunday Night: I expected Partly Cloudy skies, with low temperatures in the upper 20s to lower 30s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast. I went too warm with the forecast, as interior areas reached the lower 20s, and New York City had lows in the upper 20s.
Score: 2/4

Verification For Today: I expected Mostly Cloudy skies and a slight chance of rain and snow showers after 3 PM. I expected high temperatures in the mid to upper 30s north and west of NYC, and in the lower 40s for NYC and closer to the coast. The actual temperatures were slightly warmer than I expected.
Score: 3/4


An update for tomorrow's storm is coming soon along with a snow map and detailed forecast for each part of the area, along with an update for the possible late week storm and how it might affect the New York City tri-state area.

Saturday, February 20, 2010

Forecast Change For Tonight

There has been a very interesting trend recently that caused my overnight temperature forecast to bust. In the past few days, the overnight period had increased clouds, which prevented temperatures from going down all the way to the forecasted lows. The same thing appears to be happening tonight, with the cloud cover currently mostly cloudy across most of the area, and temperatures are steady in the upper 30s. As a result, I went warmer with the forecast temperatures for tonight and tomorrow night, being in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Feb 20: Stormy Weather Returns

Verification For Friday Night: I expected Partly Cloudy skies, with low temperatures in the mid to upper 20s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast. Once again, cloudy skies prevented the temperatures from dropping, which stayed in the lower to mid 30s across the area.
Score: 2/4


Today: Mostly Sunny. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

Tonight: Mostly Cloudy. Low temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Tomorrow: Partly Cloudy. High temperatures will be in the lower 40s north and west of NYC, and in the mid 40s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the upper 20s to lower 30s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast.

Monday: Mostly Cloudy. A slight chance of rain and snow showers after 3 PM. High temperatures will be in the mid to upper 30s north and west of NYC, and in the lower 40s for NYC and closer to the coast.

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Mild And Dry Weekend

Enjoy the mild and dry conditions this weekend, because once the next week starts, things become very active. Cloud cover will remain generally partly cloudy this weekend, with high temperatures generally in the lower to mid 40s. Low temperatures will be in the mid to upper 20s inland, and in the lower to mid 30s for New York City and closer to the coast.

Storm 1: Monday-Tuesday, Rain and Wintry Mix

This week should be very active, and the active period already starts on Monday with the first storm approaching. This storm will have at first a primary low that moves through the Ohio Valley, then towards the southern Great Lakes, with snow into places such as Michigan. While still there, the blocking should be weaker this time than the past few storms, and it will still prevent the storm from completely moving through the Great Lakes without forming a secondary low.

The primary low, meanwhile, should pull in enough warm air to bring rain and wintry mix to western Pennsylvania, with light rain/snow starting to fall in the NYC area. There are some problems that will prevent us from having mainly snow, such as the lack of a source of fresh cold air, and there isn't a high pressure to lock in the cold air. As a result, once the secondary storm forms somewhere near the Delaware coast, it should start moving northeast and intensify, but for a while, the warm air continues to impact the area, with the changeover to rain or a wintry mix for the New York City area.

Once the storm passes near the area, it could end up pulling in enough cold air for at least a changeover back to snow in the northwestern parts of the area and a wintry mix for places north and west of New York City, though that should not accumulate too much, if at all, as the storm then starts to exit the area.

Below is my updated scenario map, along with a forecast for cities and some areas.

Washington DC: Rain.
Philadelphia: Rain, a brief snow/mix possible early.
New York City: Light snow/mix changing over to rain.
Northern New Jersey: Light snow, changing over to mix in the NW parts and rain for the north central and NE areas. Changeover to snow is possible in NW NJ at the end.
Boston: Snow to start, changing over to a mix. Rain is possible from Boston and further south.



Storm 2: Thursday-Friday, Snow To Our North

As I mentioned yesterday, another storm is possible on Thursday and Friday, however the track of the storm is still very uncertain. The models continue to be all over the place with the location of the storm, and will most likely continue to do so until they find a consistent solution for the storm on Tuesday.

What we do know at this time is that this storm should originate in the south, probably bringing some snow to those areas. The storm then starts moving towards the coast and offshore, however this is where the uncertainty is. Some models such as the GGEM take this storm offshore with no impact, while the GFS takes this storm north, then northwest into the Northeast where it stalls, with a lot of snow for interior locations, rain to heavy snow for coastal New England, and some rain/snow for the New York City area. While I do not expect the models to lock onto a solution anytime soon, the recent trend has been that each storm is slightly north of the other, so at this time, while it is impossible yet to determine exactly what this storm will do, I am currently thinking that the interior Northeast has the highest risk of a snowstorm. This can still change though.

Storm 3 To Follow?

This is even further into the long range, though the models have also been showing another storm to affect the area during the time period between March 1 and March 4. The pattern is still supportive of a possible Mid Atlantic and Northeast snowstorm, but not as much as it was in the past month. More details will follow on this potential storm if it is still there in the medium range.

Friday, February 19, 2010

Feb 19: Another Possible Storm Late Next Week

Verification For Thursday: I expected Partly Cloudy skies, with high temperatures in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast. NYC did not make it to the mid 40s, but the temperatures were still in the range.
Score: 4/4

Verification For Thursday Night: I expected Partly Cloudy skies, with low temperatures in the mid to upper 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast. I was too cold with the lows, as the cloud cover was still cloudy, which prevented temperatures from going cold.
Score: 2/4


Tonight: Partly Cloudy. Low temperatures will be in the mid to upper 20s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast.

Tomorrow: Mostly Sunny. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the mid 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Sunday: Partly Cloudy. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

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Mild Conditions Continue

It will continue to be mild, with temperatures still generally in the lower to occasionally mid 40s, and in the upper 30s for the northwestern parts of the area. Conditions are expected to remain dry this weekend, with cloud cover being partly sunny.

Wintry Mix And Rain For Monday Night to Tuesday

The next storm to impact the area will approach during Monday, and affect us between Monday night and Tuesday. My thoughts are similar to yesterday, though in my update tomorrow, I am planning on possibly extending the mix zones slightly further north, up to south-central New York, northern Pennsylvania, all of Massachusetts, and the southern 1/3rd of New Hampshire, mainly because the primary storm might be slightly further north and warmer than I am expecting it to be.

Below is what my current thinking is for the timing of the storm and precipitation types. **All of this is still subject to change.**

Going according to my current thinking, I would expect Monday afternoon to bring increasing clouds to the area, with precipitation starting during the overnight hours. Light snow should start in northern NJ, a wintry mix for central New Jerseyand Philadelphia, and light rain for southern New Jersey and Long Island.

A few hours after the precipitation starting, Philadelphia and central New Jersey should change over to mainly rain, along with Long Island. A wintry mix with some rain then falls in New York City, with an intensifying wet snow/occasional rain for most of northern New Jersey. As the secondary storm develops and hugs the coast, the rest of the area except for southeast interior New York, far northwestern New Jersey and northern Connecticut change over to rain, which could be moderate to occasionally heavy. In the areas that I mentioned above that should not get into the plain rain zone, a wintry mix should fall, and while rain should occasionally mix there, I don't expect it to be the dominant precipitation type.

What I mentioned above is only my current thinking, and as I said, is still subject to change. We could see a slightly further south solution, where we see more mixing and not as much rain, or a further north solution, where we get a brief mix to rain. I am planning on making a more detailed precipitation type map and a snow accumulation map tomorrow.

Another Possible Storm Late Next Week

Just after we get a storm early next week, yet another storm appears to possibly affect the area late next week. After Tuesday's storm moves through, we will have colder conditions in place, however the storm from Tuesday will pull in enough warm air so that places such as eastern New England have yet to be affected by these colder conditions. Another storm is then shown on the models, however this appears to form in the Gulf of Mexico or the southern states this time, instead of going up the Ohio Valley with a secondary low forming.

While the models have yet to find a more common solution on this storm, I do think that this storm should be colder than Tuesday's storm, and it may bring snow to some places that will see a mix/rain with the storm early next week, though it is still too early to know where that will be. Stay tuned for more updates.

Thursday, February 18, 2010

February 21-24 Storm Discussion

After reviewing over some more possibilities today, I made some slight revisions to my scenario map from yesterday, though I'm not planning on making much more changes unless a significant change happens in the pattern forecast. The models may still be all over the place, some of them suppressed and others further north, but the real hint that helps us determine where the storm ends is the pattern.

The main factor that caused all of the storms this year to take a south track was the polar vortex, or the PV. So far this year, it's been quite strong, which blocked the storms from going too far north, and the storms that did try and move north had to transfer their energy to a secondary low, being a coastal storm. The latest forecasts show that this blocking pattern should weaken some by the time that this storm arrives, and with the past few storms having taken a track supportive of widespread snow in the Mid Atlantic with a strong PV, a weaker PV will allow this storm to move further north. Another factor that may be an issue for this storm is the lack of a 50/50 low (a low pressure located near 50N, 50W), which is an important factor in winter storms.

Another problem that we have is the lack of any real cold air. The storm should not have too much cold air at first, and there isn't a high pressure to our north to lock in the cold air. With the primary storm also being able to travel further north due to the weakened PV, more warm air will be drawn into the area. This set up would bring enough warm air that the major cities along Interstate 95 change over to a wintry mix and/or rain. The wintry mix could even end up extending as far inland as central Pennsylvania, most of Massachusetts and southern Maine.

Below is my current scenario map for this storm. Unless there are any major changes, I am planning to stay with this discussion until Saturday, when I should probably make a more detailed map, with accumulation ranges and areas where rain, mixing and snow are possible. Here are also my current expectations for each city:

Washington DC: May start out with a brief mix, but otherwise rain.
Philadelphia: Some mixing is possible at the start, followed by a changeover to rain.
New York City: Some wet snow to start, some accumulations possible, followed by a changeover to mix/rain.
Boston: Snow to start, followed by some mixing later on. Rain could mix from Boston and further south.


Feb 18: Monday Night Storm Update

Verification For Wednesday Night: I expected Mostly Cloudy skies, with low temperatures in the lower to mid 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast. While the northwestern areas had lows in the mid to upper 20s, the rest of the forecast verified.
Score: 3/4


Today: Partly Cloudy. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

Tonight: Partly Cloudy. Low temperatures will be in the mid to upper 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Tomorrow: Partly Cloudy. High temperatures will be in the mid to upper 30s north and west of NYC, and in the lower 40s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the mid 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

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Update on Early Next Week

Last night, I posted my first scenario map for this storm, showing my current thinking. Despite the models still all over the place, with the GFS and GGEM showing a suppressed storm and the EURO being too far north and west, the pattern can still help us figure out where the storm could end up.

The blocking pattern that has sent storms to our south this whole winter is showing signs of starting to weaken, not completely collapse but weaken enough to allow the storm to travel further north. Despite the storm tracking further north, the blocking is still strong enough to prevent the storm from going all the way inland, so if the storm follows my thinking and travels through the Ohio Valley, it would form a secondary low further east. It could end up anywhere from the Delmarva Peninsula to slightly north of New York City, and move northeast from there while intensifying.

The history of trends with this current pattern is that usually between the 3-5 day range, the storm does a big trend, either north or south, which is slightly moderated in the very short range, and also why some places such as Maine with the last storm had much less snow than expected. The models are still all over the place, though I do think that the models should correct themselves to start showing a further north solution. Even if the solution is further north, it can still end up busting, as Tuesday's storm showed us when the models were consistent with heavy snow into most of Maine until the last day before the storm.

While I am staying my thoughts from yesterday, expecting a wintry mix in the area with mainly rain for eastern Long Island, note that it can still change as there are still 4-5 days until the storm. By at least Saturday, if the model consensus is south, then I may adjust my forecast further south, otherwise I continue to expect a north solution.

Wednesday, February 17, 2010

Early Week Storm Scenario Map

Below is my first scenario map for the storm next week. I am thinking at this time that we have a storm moving through the Ohio Valley, with a transfer to another storm that hugs the coast, or moves slightly inland.

While not included in the wintry mix area, there can be some mixing in the area from central Pennsylvania to northwestern New Jersey, to central Massachusetts, and southeastern Maine.

**Note: This map is only to show my early thoughts, and is subject to change.**


Feb 17: Uncertainty For Next Week

Verification For Tuesday Night: I expected Mostly Cloudy skies, with low temperatures in the lower to mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast. The forecast was correct, though some areas in northwestern NJ and southeast NY saw low temperatures in the upper 10s.
Score: 4/4

Verification For Today: I expected Partly Cloudy skies, with high temperatures in the mid to upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast. While the exact high temperatures have yet to be reached, cloud cover in the afternoon kept temperatures colder than expected, with the temperatures as of now in the mid 30s across the area.
Score: 3/4


Tonight: Mostly Cloudy. Low temperatures will be in the lower to mid 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Tomorrow: Partly Cloudy. High temperatures will be in the upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the lower to mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast.

Friday: Partly Cloudy. High temperatures will be in the mid to upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast.

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Uncertainty For Next Week's Possible Storm

The models continue to show different solutions with not much consistency. The most unconsistent model is the GFS, which showed some very strange runs, including its 00z run where it had a low pressure off the Georgia coast, with precipitation all the way into southern Canada. The 12z GFS showed a snowstorm for the area, however I do not expect it to become more consistent until at least tomorrow or Friday.

The other models are starting to show hints of a Miller B storm, showing a scenario where the storm tries to move up near the Appalachian mountains but due to blocking, is forced to transfer its energy to a developing coastal low. This solution would be similar to the track of the February 5-7 storm. These models also bring in warmth, resulting in a wintry mix for New York City and rain for the Mid Atlantic, which could cause a potentially massive flooding for that area if verified, due to the deep snow cover currently in place there.

Looking at some factors other than the models, there are some clues to help us determine the track that the storm could possibly take. There has been a good amount of blocking this winter, preventing storms from going all the way up the Great Lakes or Appalachians and forcing them to transfer their energy to a coastal low. There has also been a trend that most storms continue to move slightly north of the other, with the February 5-7 storm affecting the Mid Atlantic, the February 10 storm affecting the northern Mid Atlantic, and the February 16 storm affecting the northern Mid Atlantic and southern New England.

While it's too early to know more details about the storm's potential track and impacts, my first guess would be that the storm tracks through the Ohio Valley, transferring its energy to a coastal low off the coast of Delaware or New Jersey that moves northeast, bringing a wintry mix to the major cities along I-95 and heavy snows for the interior Northeast and New England. This is just my current thinking, and is subject to change as there is still uncertainty. Stay tuned for more updates on this potential storm.

Tuesday, February 16, 2010

Feb 16: Storm Potential Next Week

Tonight: Mostly Cloudy. Low temperatures will be in the lower to mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast.

Tomorrow: Partly Cloudy. High temperatures will be in the mid to upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the lower to mid 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

Thursday: Partly Cloudy. High temperatures will be in the upper 30s to lower 40s north and west of NYC, and in the lower to mid 40s for NYC and closer to the coast.

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Short Term Forecast:

Light to moderate snow continues to fall across the area, with accumulations from barely an inch to as much as 8-10 inches being reported in the NYC tri-state area so far. The highest snow totals are coming out of northeastern New Jersey and southern Connecticut.

The back end of the snow is currently in Orange and western Bergen counties, with a band of moderate snow, and is slowly moving east. Expect snow to end in northern New Jersey and southeastern New York between 5 and 6 PM, and in Long Island between 7-10 PM.

Dry, Mild Week Ahead

After today's storm, the rest of this week is expected to be dry, however temperatures should be near to slightly above average, bringing an end to the consistently below average temperatures since late January. High temperatures are expected to be anywhere between the mid 30s to the low-mid 40s, which will melt some of the snow pack on the ground. By the early weekend, a weak clipper is likely to pass to our south, and should only bring light snow accumulations to the Mid Atlantic as it will not have enough moisture to become a big snow producer. It may affect the area with some light snow, however that is still uncertain.

Big Storm Early Next Week?

After a break from the big, historic-level snowstorms, it appears that yet another one is possible early next week. While there is still a lot of uncertainty, some model runs have showed a big storm, with the 00z ECM run bringing 1-2 feet of snow from Washington DC to Boston. The GFS model is all over the place, having shown a storm moving through the Great Lakes in its 06z run, and a moderate snowstorm on the 12z run. The pattern is also favorable, with a negative NAO and AO and a neutral PNA. While there is still about a week left until this storm, this is the time period to keep an eye for the next big storm potential.

12 PM Update - Very Heavy Snow

Very heavy snow is currently falling across parts of the region, with snowfall rates up to 2-3 inches per hour. This round of very heavy snow should come to an end in the next hour or two, though with the current rate of snow, places in northern New Jersey and southeastern New York can easily exceed 4 inches of snow, with southwestern Connecticut having over 5-6 inches of snow.

The back edge of the snow is currently in eastern Pennsylvania, and should start moving further east soon. Expect snow to end in the area between 2 and 5 PM.

11 AM Storm Update

The storm took a few unexpected turns last night and this morning. The coastal low did not develop as far north as originally thought, over southern NJ instead of over NYC, which is why I lowered my forecast amounts last night. However, the storm's snow then moved north, with heavy snow entering Connecticut, Long Island and SE NY, with several inches accumulating there.

More snow from the upper level low in Pennsylvania then managed to move east past Pennsylvania, which is currently affecting the area, bringing an additional several inches of snow to the region. While northern New Jersey currently has the lower totals out of the area, most of the area has more than 2 inches of snow as of now.

This snowstorm, with several inches of snow, will bring the monthly snow totals even higher than they were up to today. In fact, some places may make this their snowiest month since February 2003, and there's still 12 more days left of the month.

Monday, February 15, 2010

5 PM Storm Update

From looking at the latest radar, the storm does not appear to be very organized, and we also have a lot of dry slots. We currently have a band of moderate snow near Philadelphia moving northeast, but behind it is barely anything, only a few snow showers. Temperatures are also above freezing, which isn't too supportive of the snow sticking on the ground.

I normally don't do this in the last minute before the storm, but I decided to lower my forecast snow totals to the updated list below: (Updated at 8 PM)

Long Island: Less than 1 inch, mixing with rain
New York City: Near 1 inch, some mixing early
NE New Jersey: 1 to 2 inches
NW New Jersey: 1 to 3 inches
Hartford, CT: 2 to 4 inches
Boston, MA: 3 to 6 inches, some mixing possible.

Feb 15: Some Snow Tonight, Dry Week Ahead

Verification For Saturday Night: I expected Mostly Cloudy skies, with low temperatures in the lower to mid 20s across the area. The forecast temperatures were slightly colder than the actual lows, as the whole area was in the mid to upper 20s.
Score: 3/4

Verification For Sunday: I expected Partly Cloudy skies, with high temperatures in the mid 30s north and west of NYC, and in the upper 30s for NYC and closer to the coast. The forecast was correct.
Score: 4/4

Verification For Sunday Night: I expected Partly Cloudy skies, with low temperatures in the lower to mid 20s across the area. The temperatures were correct for the interior, though NYC and areas closer to the coast had lows in the mid to upper 20s.
Score: 3/4


Today: Increasing Clouds. A chance of light rain and snow after 2-4 PM. High temperatures will be in the mid to upper 30s across the area.

Tonight: Snow, mixing with rain south and east of New York City. Low temperatures will be in the mid 20s north and west of NYC, and in the upper 20s for NYC and closer to the coast.

Tomorrow: Snow, mixing with rain south and east of New York City, ending before 10 AM. High temperatures will be in the lower to mid 30s across the area.

Tomorrow Night: Mostly Cloudy. Low temperatures will be in the lower to mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast.

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Accumulating Snow Tonight, But How Much?

Out of the many possibilities for this storm tonight, it is clear that we will be seeing accumulating snowfall, but with the latest trends on the models, and the fact that there is still no agreement with the models, the snowfall amounts aren't certain yet.

We are looking at a Manitoba Mauler (a storm that moves out of Manitoba, very similar to an Alberta Clipper but the area of origin is different) that is currently in the Ohio Valley, and is expected to track just south of NYC and further northeast towards the coast of southern Maine. This is not going to be a strong storm as the previous few storms were, so we should not see much, if any snow amounts over 12 inches anywhere out of this storm, but snowfall amounts up to 8-10 inches at most are possible somewhere in the Northeast once the storm starts to intensify.

There are some issues that should limit snowfall amounts in the area. One of them is mixing, however that is more likely to take place south and east of New York City. The second issue is the lack of precipitation, as the storm intensifies too late for the area to get precipitation amounts higher than 1/2 inch. Another issue is dry slotting, as the forecast low position could bring dry slots to the area, ending precipitation early and limiting snow accumulations.

Below is my final forecast and snow map for this storm, with snow forecasts for some cities and areas also listed below.

Washington DC: 1 inch, mixing with rain
Philadelphia/Central NJ: 1 to 2 inches, mixing with rain
Long Island: 1 to 2 inches, mixing with rain
New York City: 1 to 3 inches, some mixing early
Northern New Jersey: 2 to 5 inches, some mixing possible early in parts of NE NJ
Hartford, CT: 4 to 7 inches
Boston, MA: 3 to 6 inches, some mixing possible.





Longer Range Update

After tonight's storm, we should bethrough next weekend. Temperatures will generally be near average, in the mid to upper 30s. By next weekend, the models are hinting at another storm, and despite the time range of this storm, it also appears to be another weak storm that doesn't have much moisture to work with. The latest models take this storm to our south, with light snow moving through Virginia. There is still uncertainty, so this can trend north or south, but at this time, this storm is unlikely to become a major snowstorm for us.

Saturday, February 13, 2010

Feb 13: Update On Monday-Tuesday Storm

Verification For Friday Night: I expected Partly Cloudy skies, with low temperatures in the mid to upper 10s north and west of NYC, and in the lower 20s for NYC and closer to the coast. The forecast was correct.
Score: 4/4

Verification For Today: I expected Partly Cloudy skies, with high temperatures in the lower to mid 30s north and west of NYC, and in the mid 30s for NYC and closer to the coast. Today's cloud cover was mostly cloudy to cloudy, though the temperature forecast was correct.
Score: 3/4


Tonight: Mostly Cloudy. Low temperatures will be in the lower to mid 20s across the area.

Tomorrow: Partly Cloudy. High temperatures will be in the mid 30s north and west of NYC, and in the upper 30s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the lower to mid 20s across the area.

Monday: Mostly Cloudy. A chance of light rain and snow after 2-4 PM. High temperatures will be in the mid 30s across the area.

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Monday Night-Tuesday Storm Update

Today's models have taken a rather significant north trend from yesterday. The GGEM, which was the southern outlier yesterday, now brings moderate to heavy snow much further north, and the GFS and NAM models are bringing snow into northern New England with a mix of snow, sleet and rain in the NYC area. The 18z GFS did trend slightly further south than the 12z GFS, and I do think that we should not see the storm trend much further north, if at all. I'm expecting the storm to trend slightly further south at this time, but not as far south as my thoughts from yesterday.

Below is my second scenario map for this storm. The light snow area is for 1-3 inches, the moderate area is for 3-6 inches, and the heavy area is still uncertain, but is where I think the potential is for 6-8 or more inches of snow. Places in the purple areas should see mixing.

Note that my map is based on a slight south trend. If the models remain the same or trend slightly further north, then mixing would extend into eastern Pennsylvania, northern New Jersey, most of Connecticut and towards Boston.



Friday, February 12, 2010

Feb 12: Snowstorm On Monday Night

Verification For Thursday Night: I expected Mostly Clear skies, with low temperatures will be in the mid to upper 10s north and west of NYC, and in the upper 10s to lower 20s for NYC and closer to the coast. The low temperatures stayed steady overnight, which was warmer than I expected. The actual low temperatures were in the lower to mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast.
Score: 2/4

Verification For Today: I expected Mostly Sunny skies, with high temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast. The forecast was correct.
Score: 4/4


Tonight: Partly Cloudy. Low temperatures will be in the mid to upper 10s north and west of NYC, and in the lower 20s for NYC and closer to the coast.

Tomorrow: Partly Cloudy. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to 30s for NYC and closer to the coast.

Tomorrow night: Mostly Cloudy. Low temperatures will be in the lower to mid 20s across the area.

Sunday: Partly Cloudy. High temperatures will be in the mid 30s north and west of NYC, and in the upper 30s for NYC and closer to the coast.

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Dry Weekend Ahead

Conditions are expected to remain dry this weekend, while a significant snowstorm continues to affect areas unusually south, such as Georgia and South Carolina, through early tomorrow morning. High temperatures will be below average tomorrow, in the lower to mid 30s. Sunday will be slightly warmer, with high temperatures in the mid to upper 30s across the area. Both days will have partly to mostly cloudy skies.

Snowstorm Early Next Week:

The models remain consistent with showing a snowstorm next week, though it is not expected to be anywhere as intense as the past few storms. What we have consistency with is that a weak, moisture starved storm is expected to move out of Canada and head southeast towards the Mid Atlantic, dropping light to moderate snow towards Kentucky and Tennessee. The storm then turns east and northeast from about southern Virginia, with room for intensification.

The GFS shows the storm intensifying while passing just east of New Jersey, bringing moderate precipitation from Washington DC through Philadelphia and NYC towards Boston. Other models, such as the GGEM, take the storm out to sea, with no snow north of Philadelphia. The GGEM, however, has been trending north in its past few runs, and with more accurate short range models such as the NAM showing it closer to the GFS, I think that we are most likely going to see snow out of this. The question is how much snow, as we have yet to see if the storm follows what the GFS shows, which would bring at least 5 to 10 inches of snow to the area, or follows the southern solution, which brings the most snowfall towards Virginia and the Delmarva Peninsula.

Below is my first scenario map, showing my current thinking of where the light and moderate snow zones could end up. Note that this is only preliminary, and may change over the next few days.


Thursday, February 11, 2010

Feb 11: More Snow Possible Next Week

Verification For Today: I expected Partly Cloudy skies, with high temperatures in the in the lower to mid 30 north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast. The forecast was correct.
Score: 4/4


Tonight: Mostly Clear. Low temperatures will be in the mid to upper 10s north and west of NYC, and in the upper 10s to lower 20s for NYC and closer to the coast.

Tomorrow: Mostly Sunny. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the mid 10s north and west of NYC, and in the upper 10s to lower 20s for NYC and closer to the coast.

Saturday: Partly Cloudy. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid 30s for NYC and closer to the coast.

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Snow Possibility Next Week:

After the blizzard that affected the area yesterday, another snowstorm could affect us early next week, and despite the model uncertainty, it is likely that this storm will not be a big snow producer. The models are currently showing an Alberta clipper dropping out of the Midwest, affecting that area through the Mid Atlantic with light snow. An Alberta clipper is typically moisture starved, so it does not produce big amounts of snow. Then, the Alberta clipper is forecast to move offshore, but what happens next is still unknown.

Once the Alberta clipper goes offshore, it could move up the coast. If it does, then intensification of the storm is possible, however it still does not appear to have much moisture involved, so big snow amounts like those from yesterday are not expected. While we have many details that have to be narrowed down, such as the track of the storm and its intensity, it could end up bringing at least moderate snow amounts to the area between Monday and Tuesday if the trends are supportive of that happening.

Blizzard Of 2010

Yesterday, parts of the area had their biggest snowfall since February 2006, as a blizzard dumped anything from a few inches to as much as 18-20 inches of snow in the New York City tri-state area. This blizzard was the second major storm to affect the Mid Atlantic in one week, as several days earlier, a record setting blizzard hit cities such as Washington DC and Philadelphia, and spared NYC and further north.

With the addition of this blizzard, cities such as Washington DC and Philadelphia set their records for the highest snow totals in a single winter, even passing other snowy winters such as 1995-96, and there is still another month of winter left. The New York City area is still far from reaching the snowiest winter, though this storm bumped up most of the region to above average snowfall for the winter.

When the storm started in the area, a heavy wet snow fell, with mixing further south towards Philadelphia and southern New Jersey. After a very intense snow band moved into Long Island, producing very high snowfall rates, the mixing line reached the area, with sleet and rain mixing in Long Island, New York City and parts of northeast New Jersey. Some places near the coast even switched to plain rain for a while. Places north and west of New York City did not see any mixing, however places north and west of north-central New Jersey were affected by a dry slot, which also reduced snowfall amounts.

The storm, however, busted in in Connecticut, Rhode Island and Massachusetts. The heavy snow was expected to advance into these areas, producing over 12 inches of snow. Instead, the storm never got its heaviest snows past southern Connecticut, Rhode Island and Cape Cod, and places further north ended up with only a few inches of snow.

After a full day of snow, the last part of the storm left not too long after midnight, when a band of heavy snow that affected Long Island with lighter snow in northeastern New Jersey and Connecticut left the area.

Wednesday, February 10, 2010

Feb 10: Blizzard Ending, More Snow Next Week?

Tonight: Snow, heavy at times over Long Island, ending between 10 AM and 2 AM. Low temperatures will be in the mid 20s north and west of NYC, and in the upper 20s for NYC and closer to the coast. Additional snow accumulations of 1 to 2 inches possible west of NYC, and 3 to 5 inches in Long Island.

Tomorrow: Partly Cloudy. High temperatures will be in the in the lower to mid 30 north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the mid to upper 10s north and west of NYC, and in the upper 10s to lower 20s for NYC and closer to the coast.

Friday: Mostly Sunny. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

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Blizzard Of 2010 Ending

What proved to be the biggest blizzard for parts of the area since February 2006 is now ending across the area. It is still snowing from Passaic county and further east, however that line is slowly going to move to the east as the storm exits the area. Most areas ended up with near or over a foot of snow, with some places getting slightly less. For example, from New York City and further south/east, the snow was mixing with sleet and rain occasionally, and temperatures were near to slightly above freezing, which slightly reduced snow amounts. Places not too far north and west ended up with much higher snow totals, with northeast New Jersey seeing 12-18 inches of snow. I will do a complete storm recap tomorrow morning, including more detailed descriptions of the storm's effects on the area, the bust zones, and where the storm overperformed.

Dry Weather Coming Ahead:

Luckily for the clean up for this storm, conditions through this weekend should remain dry. The only notable storm in the eastern United States will be one moving through the south, bringing snow and ice to places as far south as Georgia, Alabama and Mississippi. Temperatures will remain below average, generally in the 30s for high temperatures.

More Snow Possible?

And just after we get hit by a blizzard, and Washington DC to Philadelphia having seen two of them in a row, models are hinting of yet another snowstorm to impact the area next week. The 18z GFS run showed an Alberta clipper moving out of the Midwest, and reaching Virginia before intensifying into a nor'easter, dumping 5 to 8 inches of snow from Washington DC to southern Maine. There is still uncertainty as this is in the longer range, and the models do not have much consistency yet, however this is the time period to be looking at our next snow potential.

Tuesday, February 9, 2010

February 9-10 Storm Updates

I will be doing updates for this storm throughout this evening and tomorrow. Each update will be added onto this post.

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Small Updates: (Here I will do shorter, less detailed updates of the storm.)


8:09 PM: The snow is still falling across the area, however it is lighter than earlier today. Northern New Jersey and Southeastern New York are currently seeing light to moderate snow, with New York City, Long Island and southern Connecticut seeing moderate to heavy snow. The coastal low apparently briefly stalled earlier today, however it is now starting to move away from the area. We should see the snow exiting the north and western areas first, in the next 1-2 hours. Afterwards, areas from NYC and north/west will see their snow end between 10 PM and 12 AM, with Long Island seeing snow until at least 1-3 AM tomorrow morning.

4:26 PM: The strongest banding of this storm has formed in southern Long Island, and from NYC and further west and south. Areas in central New Jersey could end up with as much as 17-22 inches of snow by the time that the snow ends. Northern New Jersey, southeastern New York and southern Connecticut, however, should stay north of this additional heavy snow. Totals in northern New Jersey should end up being between at least 8 to 14 inches, with locally lower or higher amounts.

2:47 PM: Snow is now falling across the whole area, as colder air is moving towards the coast. It appears that most of Connecticut so far has had less snow than expected, and while the snow should intensify there later this afternoon into tonight, I wouldn't expect any widespread accumulations over 14 inches there. The heaviest snow is currently located over Long Island, New York City, northern and central New Jersey.

12:51 PM: Places north and west of New York City are still seeing snow, with snowfall amounts anywhere from 6 to 12 inches as of now. New York City and Long Island are seeing rain and sleet mixing in with the snow, limiting accumulations. More precipitation is now moving into northern New Jersey from Long Island, and while the mixing line could continue to slowly crawl to the north and west over the next hour or so, by at least 2-3 PM we should start seeing this line move away from the area and out to sea, with temperatures starting to cool down.

9:22 AM: Snow continues to fall heavily across the area, with sleet occasionally mixing in for Long Island and places south of New York City. West of New York City, the snow should temporarily end due to the dry slot, however east of NYC, it appears that the snow will continue as more snow bands are forming south of Long Island, moving north. The mixing line will continue to slowly move north, reaching its peak by at least noon, and moving back south and east again.

8:20 AM: Heavy snow is currently affecting the whole region, with snow rates generally between 1 and 2 inches per hour, locally higher. The heaviest snow is currently over NW Long Island and far SE New York, slowly moving north. In that band of snow, expect very low visibilities, with snow rates up to 3-4 inches per hour possible. The snow will then temporarily become light after at least 9 AM due to a dry slot, before more snow moves in later on.

7:36 AM: A very heavy snow band is currently entering southern Long Island, with the snow intensity up to 50 DBZ. Snow could accumulate very heavily there in the next hour or two. A dry slot is also moving north towards Trenton, and should enter northern NJ after this snow band. Behind the brief dry slot, another round of moderate-heavy snow is developing.
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Wednesday, February 10
6:45 AM Update:

Heavy wet snow started to fall in the last hour across the New York City area, and will continue to move north to affect places north of NYC. Current accumulations in the area vary from a coating to as much as several inches of snow. Moderate to heavy snow is expected to continue throughout the day.

The mix line, however, is appearing to be further north and west than originally thought, with Philadelphia and Washington DC having previously reported a wintry mix despite their forecasts not expecting any mixing. The areas where mixing could occur between at least 9 AM and 12 PM is in Long Island, New York City, and parts of Northeast New Jersey.

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9:25 PM Update:

The dry slot is slowly starting to move NE and out of the area, meaning that the snow is getting closer, and will most likely start falling within the next 1-3 hours across the area. While temperatures in the immediate New York City area are still in the upper 30s to lower 40s, once the snow starts, temperatures will quickly drop, most likely towards the lower 30s, with wet snow starting to accumulate.

The latest model, the 00z NAM, just came in and was much wetter than its previous runs, bringing 1.75 to 2.00 inches of precipitation, or 17.5 to 20 inches of snow. I would not trust this last minute trend too much, as last Saturday, the GFS made a last minute trend north to show 5 to 7.5 inches of snow for parts of northern New Jersey that did not see snow at all. However, considering that some other short range models such as the NMM and ARW also showed something similar, an increase in snowfall amounts is one of the many things to keep an eye on for this storm.

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6:45 PM Update:

There is currently heavy wet snow starting to fall across northern Virginia, Maryland and southern Pennsylvania, accumulating rather quickly. Temperatures are slowly dropping for the New York City area, currently between the mid 30s and lower 40s, with cloudy skies. The coastal storm that will impact us tomorrow is currently intensifying in North Carolina, moving to the northeast.

One area of concern currently is a dry slot developing in central Pennsylvania, which was not modeled. This dry slot is currently expanding, which could delay the storm's starting time north and west of New York City. As the coastal storm continues to intensify, we should see snow cover that region again, however this dry slot is something to watch out for, as if it holds steady for long enough, it could have an impact on the final result of the storm.

Feb 9: Blizzard For Tomorrow

Verification For Monday Night: I expected Mostly Clear skies, with high temperatures in the mid to upper 10s north and west of NYC, and in the lower to mid 20s for NYC and closer to the coast. The interior was warmer than I expected, in the lower to mid 20s, with NYC in the mid to upper 20s.
Score: 2/4

Verification For Today: I expected Increasing Clouds, with high temperatures in the mid to upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast. While interior areas were also in the lower 40s, the forecast for New York City verified.
Score: 3/4


Tonight: Cloudy. Snow starting after 10 PM to 12 AM, mixing with sleet and rain for the coast and Long Island. Low temperatures will be in the mid to upper 20s north and west of NYC, and in the upper 20s for NYC and closer to the coast. Snowfall accumulations between 1 and 3 inches possible.

Tomorrow: Heavy Snow and Windy. Some rain or sleet may mix in early for Long Island and the coast. Blizzard conditions possible at times. High temperatures will be in the upper 20s to lower 30s across the area. Snowfall accumulations between 6 and 12 inches possible.

Tomorrow Night: Snow ending before 12 AM. Low temperatures will be in the lower 20s north and west of NYC, and in the mid 20s for NYC and closer to the coast. Snowfall accumulations between 1 and 2 inches possible.

Thursday: Mostly Cloudy. High temperatures will be in the in the lower to mid 30 north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

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Storm Update For Tomorrow:

The model runs last night did appear to back away from the southern trend, and as I said when making my map last night, that would easily put us with 8 or more inches of snow. This now appears to be the case, with the forecast models showing us with over 10 inches of snow. However, this north trend means that the mix line also moved north. With temperatures being above freezing at first, precipitaiton should start as a mix for New York City, Long Island and coastal New Jersey. The precipitation will start out mainly light late this evening, and steadily intensify until the morning hours.

By tomorrow, when the storm begins to rapidly intensify off the coast, the storm will pull in colder air, and we will see the transition for snow by early tomorrow morning in most of the area, except far eastern Long Island and the central and southern NJ coast, which should change over to snow later in the day. Conditions will also become increasingly windy, with blizzard conditions possible at times closer to the coast. As the storm intensifies, so will the snow, which will become heavy across the area, producing snow rates of up to 1-2 inches per hour.

The snow will then begin to taper off from west to east tomorrow evening, ending mainly before midnight. Snow total accumulations could be well over a foot in some areas, making this the biggest snowstorm for the whole NYC Tri-State area since February 11-12, 2006, when a blizzard dumped a record 26 inches of snow in Central Park.

Below is my final snow map for the area. If you are in the light pink area, you could start out with a snow/sleet mix before changing over to heavy snow by tomorrow morning, with 9-15 inches of snow possible. In the dark pink area, a wintry mix is expected until the afternoon before the changeover to snow, with 4 to 9 inches of snow.



Forecast For Late Week:

After this storm, we are not looking at any storm through next weekend, with dry condition remaining. High temperatures will be near to slightly below average. This quiet period does not last much longer, with the potential next storm threat by early to mid next week.

Monday, February 8, 2010

Preliminary Snow Map

Below is my first snow potential map for Wednesday's storm. In my discussion, I stated 5-10 inches are possible for New York City because of the trends, however if the south trend does not continue, then we could be easily looking at 8+ inches of snow. Near-blizzard conditions are also possible from New York City to Southeastern Massachusetts, as wind gusts should also get stronger during the storm.

Feb 8: Snow On Wednesday

Tonight: Mostly Clear. Low temperatures will be in the mid to upper 10s north and west of NYC, and in the lower to mid 20s for NYC and closer to the coast.

Tomorrow: Increasing Clouds. High temperatures will be in the mid to upper 30s north and west of NYC, and in the upper 30s to lower 40s for NYC and closer to the coast.

Tomorrow Night: Cloudy. Snow starting after 11 PM to 2 AM. Low temperatures will be in the lower 20s north and west of NYC, and in the mid 20s for NYC and closer to the coast. Snowfall accumulations between 1 and 3 inches possible.

Wednesday: Snow. High temperatures will be in the upper 20s to lower 30s across the area. Snowfall accumulations between 5 and 8 inches possible.

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Wednesday Storm Forecast:

If I were to go by yesterday's forecast models, we would be looking at a foot plus snowstorm for the area, with a lot of snow. However, all of the models today have trended away from this, with less precipitation for the area and slightly further east, bringing New York City 6 to 10 inches of snow, instead of what could have been 12 to 18 inches of snow. The latest runs of the GFS and the NAM models keep the heaviest precipitation from north of Washington DC to Philadelphia and central NJ. In fact, the latest forecasts from the HPC (Hydrometeorological Prediction Center) no longer have northern New Jersey in a high risk for over 8 inches of snow. While we are looking at an intense storm, with blizzard conditions possible for areas closer to the coast, the trend has been away from a 12+ inch storm for the area. I would wait until tonight's runs before making any additional forecasts, but if the 00z runs (tonight's runs) do not shift north/west or trend wetter, then the New York City area is most likely not going to see over 12 inches of snow .

At this time, my current thoughts would be for 8-14 inches from Washington DC to Philadelphia with locally higher amounts, 5-10 inches for the New York City tri-state area, and 4-8 inches for Boston. Remember that these are preliminary forecast totals, and could change by tomorrow's final forecast for the storm, whether the models stay the same, trend south, or trend north.

Longer Range Forecast:

The next storm will approach the East Coast by next weekend, but it should not be anywhere close to affecting us. In fact, it is expected to track through Florida, and snow is possible as far south as Georgia, Alabama and Mississippi. Temperatures will remain near to slightly below average during this time period.

Forecast Verifications

Verification For Saturday: I expected snow ending in the afternoon for places west and south of NYC, with places further north having cloudy skies, starting to clear in the afternoon. I expected high temperatures in the mid to upper 20s across the area. The coast was slightly warmer, with high temperatures in the lower 30s.
Score: 3/4

Verification For Saturday Night: I expected Partly Cloudy skies, with low temperatures in the lower to mid 10s north and west of NYC, in the mid to upper 10s in the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast. The actual temperatures were in the range of my forecast, except some areas further north and west in Sussex/Orange counties that had lows in the upper single digits.
Score: 4/4

Verification For Sunday: I expected Sunny skies, with high temperatures in the mid to upper 20s north and west of NYC, and in the lower 30s for NYC and closer to the coast. The whole area ended up being warmer than I expected, with places north and west of NYC in the lower 30s, and NYC in the mid to upper 30s.
Score: 2/4

Verification For Sunday Night: I expected Mostly Clear skies, with low temperatures in the lower to mid 10s north and west of NYC, in the mid to upper 10s in the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast. The north and western areas ended up being slightly warmer than I expected, otherwise the rest of the forecast verified.
Score: 3/4

Verification For Today: I expected Mostly Sunny, with high temperatures in the upper 20s to lower 30s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast. Once again, temperatures ended up being warmer than I expected, in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast, though it was not a complete bust as some of the actual highs were in my forecast range.
Score: 3/4

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Saturday's Storm Verification:

The storm on Saturday ended up being historic or nearly historic for the central Mid Atlantic, including the corridor from Washington DC to Philadelphia. Yet some areas such as northern NJ did not get any snow out of the storm at all, which was mainly due to dry air, and the snow band stalling in central NJ. My forecast snowfall maps from Thursday and Friday were both too high with amounts for northern NJ and too low for southern NJ/Philadelphia, but I noted the potential of my forecast busting in my 11 PM storm update, correctly expecting snowfall amounts to be between 15-25 inches for central NJ and further south, with significantly lower amounts for northern NJ if the snow band was to stall there, which it did. This storm was very confusing to forecast, and based on my forecasts and the last minute update, I would give myself a B for my forecast.

Saturday, February 6, 2010

Feb 6: Watching For Next Week

A verification for today's storm will be done separately, probably either tonight or Monday.

Today: Snow will end in the afternoon for places west and south of NYC. Places further north will have cloudy skies, starting to clear in the afternoon. High temperatures will be in the mid to upper 20s across the area.

Tonight: Partly Cloudy. Low temperatures will be in the lower to mid 10s north and west of NYC, in the mid to upper 10s in the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast.

Tomorrow: Sunny. High temperatures will be in the mid to upper 20s north and west of NYC, and in the lower 30s for NYC and closer to the coast.

Tomorrow Night: Mostly Clear. Low temperatures will be in the lower to mid 10s north and west of NYC, in the mid to upper 10s in the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast.

Monday: Mostly Sunny. High temperatures will be in the upper 20s to lower 30s north and west of NYC, and in the lower to mid 30s for NYC and closer to the coast.

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Short Term Forecast:

As I mentioned in my 7 AM update, at least half of northern NJ did not see any snow from this storm at all. The cut off line of the snow was very sharp, with places in southern NYC getting as much as a few inches of snow and northern NYC not getting any snow at all. Any place that is seeing snow will probably continue to do so until this afternoon, when the snow should end. Places further north will have cloudy skies at first, clearing to mostly to partly cloudy skies later in the afternoon.

Early Next Week Forecast:

Next week appears to have a very bright start, with Monday being mostly sunny and temperatures returning into the mid 30s for areas closer to New York City. By Tuesday or Wednesday, however, things could get more interesting. The models have been showing a storm affecting the area for the past few days, with some models such as the GFS and GGEM bringing as much as 10 inches of snow in the area. We should expect more consistency to be shown probably by tomorrow night or Monday morning, which is when we should have an idea of where the storm could track. It appears as of now to be further north than today's storm, but we can't know for sure yet. Stay tuned for more updates to come.

7 AM Storm Update - Bust

Looks like I caught on last night to the possibility of this storm busting for areas north of central New Jersey. The snow's northern boundary completely stalled last night in central to northern New Jersey, and while half of northern NJ has yet to see a flake, places barely 15-20 miles south of that area have already been seeing accumulating snow.

The snow has already reached its northernmost extent, and is already starting to move slowly towards the east, meaning that those who didn't see snow in northern NJ most likely won't see it, while places from Central NJ further south are going to have very heavy snow bands continue to stall over their area. I would generally expect reports of 15 to 25 inches of snow in that area.


For those wondering when is our next opportunity to actually get snow in the area, that would be between Tuesday and Thursday with our next storm. There can be a lot of uncertainty this far out, but the models have been consistently showing a brief mix to heavy snow event for the area for the past day. Each model takes it on a different track, however. The DGEX takes the low right over us, bringing us a cold rain. Meanwhile, the GGEM and GFS dump over 10 inches of snow in the area. There is time left for the models to continue their trending, but overall this storm has a better chance of bringing us a snowstorm than the past few storms.

Friday, February 5, 2010

11 PM Storm Update

According to the latest radar, the northern boundary of the snow has stalled over central NJ, between Philadelphia, Trenton and Atlantic City. Those areas could end up with potentially 20-25 inches of snow tonight, as this band of snow continues to dump heavy snow in that region without moving.

On the other hand, this might spell trouble for my forecast in northern NJ. If the snow band starts to move north again, then we're still in the game for 3 to 6 inches. But if it continues to remain in central NJ without moving anywhere, then my forecast totals north of central NJ could end up being significantly lowered, with the totals south of that point being raised to 15-25 inches of snow.

Feb 5: Forecast For Tonight/Tomorrow

Verification For Thursday Night: I expected Mostly Clear skies, with low temperatures in the lower to mid 10s north and west of NYC, in the mid to upper 10s for the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast. For the interior, my forecast verified, but I was way too cold for NYC, which had lows in the mid to upper 20s.
Score: 2/4

Verification For Today: I expected Increasing Clouds, with high temperatures in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast. The cloud cover was cloudy during the whole day, but the temperature forecast verified.
Score: 3/4


Tonight: Snow, starting between 10 PM and 1 AM. Low temperatures will be in the upper 10s to lower 20s north and west of NYC, in the lower to mid 20s in the north and west suburbs of NYC, and in the mid 20s for NYC and closer to the coast.

Tomorrow: Snow. High temperatures will be in the mid to upper 20s across the area.

Tomorrow Night: Partly Cloudy. Low temperatures will be in the lower to mid 10s north and west of NYC, in the mid to upper 10s in the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast.

Sunday: Sunny. High temperatures will be in the mid to upper 20s north and west of NYC, and in the upper 20s to lower 30s for NYC and closer to the coast.

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Tonight's Storm: Final Forecast

We are already seeing some changes to the storm currently happening, with some locations seeing snow earlier than expected, the primary low over Kentucky slightly intensifying for a little longer, and the GFS model having trended towards more snow in the area in its latest run. Some other models that were also south, such as the GGEM, also trended slightly further north. Below is my final call for the New York City area:





Longer Range Update:

For the longer range, we have yet another storm that might approach the area during the middle of next week, between Tuesday and Thursday. While its effects are uncertain, models are hinting that this storm might be further north than today's storm, possibly bringing a snowstorm to the area. This is nowhere near final, as the models still have more time for trending, but we need to keep an eye on this time frame as it could produce our next snowfall.

Thursday, February 4, 2010

Feb 4: Weekend Storm Update, Preliminary Snow Map

Verification For Wednesday Night: I expected Partly Cloudy skies, with low temperatures in the upper 10s to lower 20s north and west of NYC, in the lower to mid 20s for the north and west suburbs, and in the mid to upper 20s for NYC and closer to the coast. The forecast was too cold in the north and west areas, in the lower to mid 20s, but everything else verified.
Score: 3/4

Verification For Today: I expected Mostly Sunny skies, with high temperatures in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast. The interior was slightly warmer, in the mid 30s, but everything else verified.
Score: 3/4


Tonight: Mostly Clear. Low temperatures will be in the lower to mid 10s north and west of NYC, in the mid to upper 10s for the north and west suburbs, and in the upper 10s to lower 20s for NYC and closer to the coast.

Tomorrow: Increasing Clouds. High temperatures will be in the lower to mid 30s north and west of NYC, and in the mid to upper 30s for NYC and closer to the coast.

Tomorrow Night: Snow, mainly after 10 PM. Low temperatures will be in the upper 10s to lower 20s north and west of NYC, in the lower to mid 20s in the north and west suburbs of NYC, and in the mid 20s for NYC and closer to the coast.

Saturday: Snow. High temperatures will be in the mid to upper 20s across the area.

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Weekend Storm Update: Potentially Historic Blizzard for Mid Atlantic, Lighter Snowfall Further North

I will split this forecast into two parts: The first one will be my thoughts for the New York City Tri-State area (the areas that I usually cover in my forecasts), and the second part will be my thoughts for the rest of the Mid Atlantic, including a preliminary potential snow map.

New York City Area Forecast:

When I made my verification for yesterday morning's storm, I noted how the NAM has trended south. This trend did not end today, but it continued even further south. In its latest run (18z), it showed a dusting of snow at most for the area. Other models have also trended south, including the EURO, the SREF, and also the GGEM, which I think the GGEM could be the outlier as it only has 1-2 inches of snow in Philadelphia, which is likely to see way more than that. However, the GFS model has trended much further north, now showing our area with 0.5 to 0.75 inches of precipitation, or 5 to 7.5 inches of snow.

With the other models well to the south, I am not convinced about it coming too far north, but we do have a very big storm with a lot of moisture that the models may be handling incorrectly, and with a weak SE ridge in place, and if the polar vortex is weaker than expected, then I can see how the storm could trend much further north.

For now, there is still uncertainty but we are starting to get an idea of what this storm will bring to the area, so my first preliminary thought would be about 2 to 4 inches in Sussex/Orange Counties, 3 to 6 inches for northern New Jersey, and 4 to 8 inches for NYC and Long Island. These totals are subject to change, and will probably be different tomorrow when I make my final forecast for the storm.

Mid Atlantic Forecast And Snow Map:

We are seeing what could be remembered as the Blizzard of 2010 in the Mid Atlantic. Blizzard warnings have already been issued in southern NJ, and with near/over 2 inches of liquid possible, we could be looking at as much as 2 feet of snow, if not slightly higher, from Washington DC to Southern New Jersey.

As such, below is my preliminary snow map. These amounts are subject to change, and are not final yet. My final map will be made tomorrow.