Tuesday, January 31, 2012

**No Update Posted 1/31/12**


No update was posted tonight. The next update will be posted on Wednesday evening, discussing the possibility for a storm in the region, possibly including the area, on Sunday and/or Monday, along with the potential changes in the pattern going into the middle of the month.

Monday, January 30, 2012

Jan 30, 2012: 60 Degrees Possible Again


Forecast Highlights:


- Warmth returns for Tuesday and Wednesday, 60 degrees possible on Wednesday
- Colder but still warmer than average for the weekend; isolated rain/snow showers?
- Slightly colder pattern likely to begin developing next week


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With the third cold front over the last 3 days moving through the area last night, temperatures were colder today, with partly cloudy skies and highs reaching the mid to upper 30s inland (NW NJ/SE NY) and the upper 30s to lower 40s across the rest of the area. Yet another front is approaching the area, but instead of a cold front, this time a large warm front extending from the Mid Atlantic to North Dakota is pushing northeast, and will completely remove any strong cold from the region by tomorrow night, leaving the entire United States with a mild air mass with the strong cold bottled up in central/northern Canada and Alaska. Prior to the warmth, the warm front is currently resulting in widespread light snow in the Northeast, which will affect parts of southern Connecticut later tonight, but little, if any accumulations are expected.

With the warm air spreading across the entire United States, very mild temperatures are expected for tomorrow and Wednesday that will bring temperatures into the mid to upper 50s across the area, making this the third time over the last 10 days that temperatures end up significantly warmer than average. On Wednesday, parts of the area may even reach 60 degrees, making it the third time this month that the 60 degree mark could be reached in parts of the area. Colder temperatures will return for the late week and the weekend but will remain warmer than average, and while uncertainty increases for a potential storm either in the weekend or early next week, indications still show that the pattern is likely to gradually become colder starting later next week and into the long range.


Tuesday and Wednesday Outlook: Very Mild


With mostly sunny skies and a southwest wind, much warmer temperatures are expected tomorrow, reaching the mid 50s in NW NJ/SE NY and the mid to upper 50s across the rest of the area. These temperatures are nearly 20 degrees warmer than the average for this time of the year. With a weak cold front approaching the area on Wednesday, even warmer temperatures are expected, reaching the mid to upper 50s with parts of the immediate NYC area possibly reaching 60 degrees. Mostly cloudy skies are expected with scattered showers from the late afternoon through the overnight hours.


Thursday - Sunday: Storm Potential Uncertainty; Still Warmer Than Average


The weak cold front will move through the region overnight with mostly cloudy skies for Thursday. The ECM model which showed a storm yesterday backed down from its previous solution, joining the model consensus for mostly cloudy skies and the potential for a few isolated showers. Temperatures will be cooler but still warmer than average, reaching the mid to upper 40s across most of the area and the upper 40s to possibly near 50 degrees in the immediate NYC area. Although these temperatures are noticeably colder than those of Wednesday, they are still at least 10 degrees above average.

A high pressure with a slightly colder air mass will move in for Friday and Saturday, bringing temperatures back into the lower to mid 40s across most of the area. There is still uncertainty regarding a potential storm for the weekend, but the models do agree on an important aspect of the storm, showing a cutoff low developing in the western United States. This development, which is becoming more likely, would allow the cold to move out of the region prior to the arrival of the storm, potentially around early next week, making it more likely that the storm would affect the area with rain rather than snow. The ECM model shows a light rain/snow potential for Saturday with no storm early next week, although right now it is the only model showing such a solution. Even though there is still uncertainty and changes are expected with the storm, at this time it appears unlikely that this storm turns into a notable snowstorm for the area. Stay tuned for more information on any storm potential.


Longer Range Update:


The latest model guidance continues to signal changes in the pattern starting next week. Unlike the previous attempts of the models to show a pattern change which failed, this potential is already within the 10 day range while most of the other failed potentials were in the 10-15 day range. The GFS was the main support for the previous attempts of a pattern change, while the majority of the models and the ensembles in this case support changes in the pattern. Although little or no blocking develops, the biggest change in the pattern is the development of a +PNA and a western US ridge. This western US ridge will bring the potential for slightly more sustained cold in the eastern US, although the placement of the ridge is the main question as the ridge may not be as strong or may spread too far east which would limit any cold/snow potential for the area. In addition, the MJO, which has been stuck in phases 4-6, is moving out of these phases and towards phase 7, possibly 8, again signaling that some changes are possible for the longer range.

This is not a complete pattern flip; any changes are not expected to stick around through the rest of the winter, and at this time appear to be more likely to focus around the mid February time frame. In addition, some aspects of the current pattern are still in place, such as the lack of any -NAO and Greenland blocking. Despite this, however, minor changes are possible with the pattern starting next week and through at least February 15, if not a bit later, which is when the area may see some more cold and at least one snowstorm potential. The latest model guidance is signaling a storm potential around February 10, and while it is too early to know any specific of the set up this far out, this time frame will be watched for any snow potential. Stay tuned for more information on the longer range.

Sunday, January 29, 2012

Jan 29, 2012: Light Snow Showers Tonight


Weather Forecast Highlights:


- Scattered snow squalls tonight, light accumulations possible with gusty winds
- Warm weather returns for Wednesday, near 60 degrees
- Storm possible for weekend: more rain and possibly snow
- Snowstorm potential still exists between February 4-15


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With the third cold front in the last 3 days moving through the region, today brought slightly colder temperatures but still warmer than average, peaking in the lower to mid 40s across the area. Looking at the latest radar posted to the left, a line of light to locally moderate snow squalls is moving through central Pennsylvania. There have been reports of quick accumulations of up to 1-2 inches in a short amount of time along with strong wind gusts with this line of snow showers. Although this line will weaken once it reaches the area, scattered snow showers are still expected from NYC and further north/west, with a short burst of moderate snow possible for western NJ and Orange county in NY. These areas may receive a quick 1/2 inch of snow tonight.

The colder temperatures will last through tomorrow, but will quickly come to an end as a low pressure tracks to the north of the region, bringing temperatures back to the 55-60 degree range for Wednesday. Although the pattern does not flip completely to a cold and snowy one, there are changes unfolding by late next week which may result in a colder and stormier pattern for the region, starting out with two storm potentials, one for Thursday and the second for the weekend.


Tomorrow's Outlook:


The coldest temperatures of this cool spell are expected for tomorrow, although these temperatures are still slightly warmer than average. Along with mostly sunny skies, temperatures will peak in the mid to upper 30s inland and the upper 30s to lower 40s across the area.


Tuesday - Thursday: Warmer And Possibly Rainy; Nearing 60 Degrees


The cold will quickly move out of the region on Monday night with a large warm front moving through the region. Some snow will fall ahead of this warm front in most of New England including southern Connecticut, with light accumulations possible towards central New England, and although isolated flurries are possible in NYC, most of the area except for southern CT are likely to stay dry. By Tuesday, a ridge will return to the region along with southwest winds and a warmer air mass moving in, resulting in temperatures warming up to the lower to mid 50s across the area, nearly 15 degrees warmer than average.

The warmest temperatures are expected for Wednesday, ahead of the next cold front. Mostly cloudy skies are expected, and cloud cover along with afternoon/evening scattered showers may limit how warm temperatures get, but widespread highs in the mid 50s are expected, with parts of the immediate NYC area reaching the 55-60 degree range. Scattered showers will continue through the overnight hours with temperatures dropping into the mid 30s to lower 40s across the area.

There is some uncertainty for Thursday regarding a storm potential. Most models do not show a storm, although the ECMWF is currently the only model showing a storm affecting the area. Both of its runs today showed rain, although its afternoon 12z run was colder than its 0z run last night. There have already been times this year when the ECM showed a storm and backed away from it, and considering that the current emphasis is on the weekend storm potential, I am expecting the ECM to trend away from the large Thursday storm solution, with the result ending up as scattered rain showers in the area and rain/snow showers in the Northeast. Mild temperatures will continue through Thursday with highs likely reaching the upper 40s to lower 50s.


Longer Range: Weekend Storm Potential


The storm potential for the weekend is even more uncertain than the Thursday potential, with the latest models showing completely different solutions, ranging from a cold rain on the CMC to heavy rain on the GFS with a large Northeast snowstorm, to no storm on the earlier GFS runs and a moderate rain/snow event on the ECMWF. It is still uncertain if the area sees a storm, but should a storm affect the area this weekend, it would be more likely to bring either a rain/snow mix or plain rain, with a snowstorm possible but not very likely at this time. Due to the large uncertainty, it is difficult to know for sure what the storm will do; stay tuned for more information on the storm potential for the weekend once details become clearer.

Beyond the weekend storm potential, there are still signs that some changes are coming to the pattern. Although these are not permanent changes, instead expected to be temporary for at least a 1-2 week time period, they are likely to bring a colder and potentially stormier pattern to the region. Stronger ridging near the western US is expected to develop, with some models hinting of weak ridging near Greenland. Although it does not appear that any solid blocking is likely to develop for this time frame, the PNA ridge is likely to make the pattern more favorable for cold and potentially snow. In addition, the MJO, which has been stuck at phases 4-6 for the last month, is finally breaking out of its locked cycle and moving towards phase 7. While phase 7 does not support sustained cold and snow in the East, and at this time it does not appear that the MJO is likely to settle in phase 8 which is more supportive of cold and snow, the MJO moving into phase 7 is a signal that the pattern is starting to weaken from where it has been until now. While it is not a guarantee that the area sees snow with this temporary pattern change, the potential is there for at least one snowstorm to affect the area between February 4 and 15, with the pattern potentially becoming less favorable for cold and snow after this time frame.

Jan 28, 2012: Cold Returns Beyond This Week?


Today brought mild temperatures across the area with partly cloudy skies, with highs reaching the mid to upper 40s across the area. Although these temperatures are still nearly 8-10 degrees warmer than average, they have noticeably cooled down from yesterday's warmth; during January 27 of last year, the area was cleaning up after the third major blizzard of the winter, while this year's January 27 brought temperatures as high as 60 degrees in parts of the area, melting most of the leftovers from the only snowstorm the area has seen so far during meteorological winter.

Temperatures are slightly cooling down through Monday, with isolated snow showers tomorrow night and possibly on Monday night, although warmth will return again by the middle of the week with temperatures once again surging into the mid 50s across most of the area on Wednesday. This will likely be the peak of the warmth, however, as the pattern begins to transition towards one that is slightly more favorable for cold and snow afterwards, starting with the February 2-3 time frame.


Tomorrow's Outlook:


With another weak low pressure moving towards the Northeast, temperatures will cool down although remain several degrees warmer than average, peaking in the lower to mid 40s inland and in the mid 40s across the rest of the area. Cloud cover will increase towards the evening hours as the low pressure moves closer; although most of the snow showers are expected to focus over Pennsylvania, isolated snow showers are possible in parts of the area.


Monday - Thursday: Warmer Temperatures Return


The coldest temperatures are expected on Monday, with partly sunny skies and high temperatures reaching in the mid to upper 30s inland and the upper 30s to lower 40s across the rest of the area. Although these are the coldest high temperatures of this 2-week time frame, they are still slightly warmer than average. A warmer air mass will return again for Tuesday with partly cloudy skies and highs reaching the upper 40s to lower 50s across the area. The warmest day will be on Wednesday, with mostly cloudy skies and highs reaching the mid 50s across most of the area, possibly passing 55 degrees in parts of the immediate NYC area in the warmer case scenario. Scattered showers are expected for the late afternoon through the evening and parts of the overnight hours, although no significant rain amounts are expected. Thursday will be slightly cooler with temperatures returning back into the mid to upper 40s.


Friday - Beyond: Colder, Increasing Snow Potentials


Uncertainty increases for this time frame, although the potential is there for a storm to affect the region, including the area, around Friday and/or Saturday. Should the storm affect the area, its impacts are still uncertain, although most of today's models have been showing a scenario closer to snow than a warm rainstorm for the area, with the latest 0z GFS run showing a moderate snowstorm for the area. The set up is still not very favorable, although there is a larger western ridge as a result of the rising PNA, allowing for colder temperatures for the East and a storm potential. Snow is possible in this time frame for the area, but until a better consensus emerges on this time frame, which may not be until Tuesday/Wednesday, this storm does not appear to be very likely to produce a moderate snowstorm across the area, and is more likely at this time to either bring some snow to rain or nothing, although the potential is there for something more than the typical rain/light snow and needs to be watched.

Beyond this time frame, the models continue to have large differences between each run, with the latest models backing away from the cold/snow signal for February 4-7 and pushing it back to the long range. Although no complete pattern flip is expected, minor changes in the pattern may bring the potential for at least one snowstorm for the area between February 4 and 15. Stay tuned for more information on the longer range as details become clearer.

Friday, January 27, 2012

Jan 27, 2012: Mild Pattern Continues Next Week


Last night, widespread light rain fell across the area with temperatures still stuck in the 30s inland and the lower 40s closer to the coast. A warm front brought much warmer temperatures this afternoon especially for coastal areas, however, with high temperatures reaching the lower to mid 50s in NW NJ/SE NY and the upper 50s to lower 60s across the rest of the area. Newark and LaGuardia reached 60 degrees today, which is over 20 degrees warmer than average, making today the second time this month that temperatures reached the 60s in parts of the area.Windy conditions were also observed today, with gusts ending up in the 35-45 mph range for most places.

Temperatures will gradually cool down but remain warmer than average throughout the weekend, with highs in the upper 40s to lower 50s tomorrow and in the lower to mid 40s on Sunday. Another low pressure will move into the northern Northeast, however, once again bringing temperatures well into the 50s across the area for the middle of next week. A slight cool down followed by rain and possibly some snow for the late week is expected, although there are signals showing up that beyond the late week, the pattern may become slightly more favorable for cold and some snow for the area.


Weekend Outlook:


Partly sunny skies are expected to return for tomorrow with dry conditions as well as a weak low pressure bring scattered snow showers for the Northeast. Temperatures will still remain warmer than average, however, peaking in the mid to upper 40s inland and the upper 40s to lower 50s across the rest of the area. An isolated snow shower may be possible tomorrow night in the north/west parts of the area.

Another weak low pressure will move through the region on Sunday, bringing increased cloud cover and temperatures reaching the lower to mid 40s across the area. More widespread snow showers are possible for Sunday night with low temperatures dropping into the low to mid 20s inland and the mid 20s to lower 30s across the rest of the area, although if any of the snow accumulates, a dusting is expected at most.


Monday - Wednesday: Warming Up Again


The milder pattern the region has seen since the start of this week will continue through most of next week as well, with the coldest day, Monday, still bringing near average temperatures, with highs reaching the mid to upper 30s inland and the upper 30s to possibly lower 40s across the rest of the area. As a low pressure moves into the Northeast, temperatures will begin to warm up on Tuesday and Wednesday with a southwest wind developing. Mostly sunny skies are expected again on Tuesday with highs reaching the upper 40s to lower 50s, with Wednesday bringing partly to mostly cloudy skies along with highs reaching the lower to mid 50s across the area, possibly even getting into the upper 50s near NYC in the warmer case scenario. Isolated showers are possible in the evening and overnight hours as a weak cold front moves through the region, although no significant precipitation is expected.


Thursday - Beyond: Stormier Pattern; Some Snow?


Uncertainty increases for the longer range starting on Thursday, although some models are showing the potential for a storm to affect the region between Thursday and Saturday. There has been a wide variety of solutions on the models for this storm, and while some snow could perhaps be possible for parts of the area, given the set up, at this time it appears that the Northeast would be more likely to see a snowstorm in this time frame should the storm affect the region. Behind this storm, however, while not immediate, some changes in the pattern are likely, including a stronger +PNA developing, which may result in colder temperatures for the eastern US starting around February 5-7, and between February 5 and 15, at least one snow event may affect the area. Stay tuned for more information on the longer range, including the late week storm potential.

Thursday, January 26, 2012

Jan 26, 2012: Rain Tonight, 60 Degrees Tomorrow


Early this morning, a surprise round of overrunning precipitation moving into the cold air in place resulted in a light rain, snow and sleet mix across most of the area, with a coating of snow observed. The cold air was much stronger than expected near the surface, with temperatures only reaching the mid 30s inland and the upper 30s to lower 40s across the rest of the area. The area has changed over to rain except for the higher elevations near NW NJ and Orange county, NY, which are seeing some freezing rain.

After the rain tonight, much warmer temperatures will return for tomorrow, reaching 60 degrees in areas near NYC. Colder temperatures will return by Sunday and Monday, although temperatures will stay above average through the end of next week temperatures. The next storm is expected to affect the region with isolated showers and yet another round of mild temperatures around the middle of next week, although there are growing indications that chances for slightly more cold and perhaps snow may increase by the first full week of February.


Tonight And Tomorrow: Rain, Wind, Warmer

As previously mentioned, temperatures at the surface were much colder than expected as the CAD (cold air damming) is stronger than expected. As a result, temperatures tonight will be colder than previously expected, sticking in the mid to upper 30s inland and the lower 40s across the rest of the area, reaching the mid 40s in Long Island by tomorrow morning. Any freezing rain in the N/W parts of the area will change over to rain by 12-1 AM.

Occasional rain will continue to fall tonight, with at least 1/4 inch of rain expected as most of the rain falls to the north of the area. By the morning hours tomorrow, a line of moderate to locally heavy rain will move through the area with gusty winds, up to 35-40 mph with some storms. Temperatures will rise ahead of the cold front early tomorrow afternoon, with highs expected to reach the mid to upper 50s across the area. Parts of the immediate NY area are even expected to reach the 60-63 degree range for highs! Most of the rain will end by the early afternoon hours tomorrow with a storm total of 1/2 to 1 inch expected, locally higher in some areas north and west of NYC, with temperatures dropping by tomorrow evening.


Weekend - Next Week: Still Warmer Than Average

Another mild day is expected for Saturday, with partly sunny skies and highs reaching the upper 40s to lower 50s across most of the area. Cooler temperatures are expected for Sunday with partly sunny skies and highs in the mid 40s for most of the area, and Monday will be the coldest day, with highs in the mid to upper 30s across the area.

Warmer temperatures will once again spread into the region for Tuesday and Wednesday as a low pressure stays to the north of the area; Tuesday is expected to bring temperatures back into the upper 40s to lower 50s, and although there is uncertainty on the exact location of the storm on Wednesday, it is likely to be far north enough to allow temperatures to rise back up above 50 degrees, perhaps getting into the mid 50s in parts of the area in the warmer case scenario. Colder temperatures will return by next weekend, with the potential for another storm to affect the region either in the late week or the early weekend. Stay tuned for more information on the longer range.


Early February Outlook:

More information on the potential pattern for early February, including the next snow chance for the area, has been posted in the Long Range Forecasts page.


Wednesday, January 25, 2012

Jan 25, 2012: Rain, Wind, Warmth Friday


As the winter season to be remembered for its lack of cold and snow continues, yet another warmer than average day was observed across the area, with temperatures reaching the upper 30s to lower 40s inland and the mid 40s across the rest of the area. A large storm will move through the region tomorrow night, bringing temperatures well into the 50s across the area with more rain, wind and possibly thunderstorms. Temperatures will cool down again by early next week, although they will remain above average.


Thursday - Friday: Heavy Rain, Wind; 60 Degrees Possible

Although the area has seen rain storms this month, the last time such a strong storm came through the region while far north enough to result in heavy rain, warmth and thunderstorms was back in late December. Yesterday's update mentioned how there was uncertainty with the storm, with the NAM/GFS models staying south with the ECM, CMC and UKMET going with a warmer scenario. As expected, the NAM and GFS were too far south, and significantly adjusted to the north with today's runs. Although yesterday's CMC and UKMET runs were a little too warm, a final solution closer to the warmer models has emerged, with a warmer, stronger and wetter storm affecting the region.

Below, each of the three main aspects of the storm is discussed in more details:


Rain/Thunderstorms: Heavy rain is expected out of this storm across parts of the area. Occasional showers will develop on Thursday afternoon, lasting through the early overnight hours. With the area in the warm sector of the storm, the heavier rain will focus to the north of the area overnight, with cloudy skies, occasional showers and rising temperatures expected. A stronger squall line will move through on Friday morning, which may contain thunderstorms for parts of the area, although the best risk of thunderstorms will be focused to the south of the area. These storms may also produce gusty winds, with more details on the wind aspect of the storm in the next section. Most of the rain will end by Friday at 12 PM with scattered showers possible afterwards. Overall, at least 1/2 to 1 inch of rain is expected, with locally higher amounts up to 1.5 inch, especially north and west of NYC.

Wind: Significant winds are possible out of this storm in parts of the area. With the area in the warm sector of the storm late on Thursday night into Friday morning, strong low level winds will result in potentially strong wind gusts under the heavier rain and convection, with gusts up to 45-50 mph possible in the stronger storms. Behind the cold front, a strong wind gradient will develop for the late afternoon and evening hours, with widespread gusts up to 40 mph possible again. A Wind Alert will likely be issued with tomorrow's update.

Temperatures: Another aspect of this storm is its temperatures. Back in the 14th of January, I mentioned in the Long Range Outlooks page that with the mild time frame already observed for this week, significant warmth would likely be observed more than once, and that at least one day could reach 60 degrees up to NYC and parts of the Northeast. The area has already seen 50+ degree weather earlier this week, and this storm will be the one that could bring parts of the area close to 60 degrees.

Temperatures will reach the lower to mid 40s across most of the area on Thursday, although with the area entering the warm sector of the storm, temperatures will steadily warm up, reaching the lower to mid 50s for most places by the morning with the immediate NYC area getting into the upper 50s. Temperatures will cool down later in the afternoon hours with a slightly cooler air mass coming in, although between the morning and the early afternoon hours, the immediate NYC area is likely to reach the upper 50s for highs, and some places may even get up to 60 degrees.


Longer Range Overview:

Unseasonable warmth will continue through the longer range, with the coldest day, Monday, only bringing near average temperatures across the area. Temperatures are expected to reach the upper 40s to lower 50s across the area on Saturday and the lower to mid 40s on Sunday, with both days bringing partly sunny skies. An isolated rain or snow shower may be possible on Sunday, although the best risk of snow will stay to the north of the area. A colder air mass will move into the region on Monday with high temperatures only reaching the mid to upper 30s across the area, although temperatures will quickly warm up again by the middle of next week, once again reaching the 40s for highs. The next potential storm is around the middle of next week, and with the latest indications once again appears likely to be a mostly, if not plain rain event. Although some changes are expected, this is not a set up to produce any notable snowstorm.

Stay tuned for more long range information with tomorrow's update, including an update on the rest of the winter and why the pattern will fail to flip to a cold and snowy one.

Tuesday, January 24, 2012

Jan 24, 2012: Rain Returns Thursday Night


Throughout the day yesterday (Monday), temperatures slowly warmed up across the area. The cold air stayed in interior areas longer than expected, leading to chilly daytime temperatures inland, although by the late afternoon temperatures quickly warmed up near the coast, with the warmth spreading inland by the early overnight hours as expected, and temperatures ended up reaching the expected highs, peaking in the mid to upper 40s inland and the lower 50s across the rest of the area. Today (Tuesday) had drier conditions again with warmer temperatures melting most of the remaining snow cover from the weekend snowstorm across most of the area, with temperatures reaching the upper 40s to lower 50s inland and the lower to mid 50s across the rest of the area.

With only a slightly cooler air mass coming in, the pattern consisting of above average temperatures and very little, if any snow has returned, with temperatures staying above average through the rest of this week and into the weekend. Stormy weather will return by Thursday night, with widespread rain and mild temperatures, and while uncertainty increases by Sunday, a weak storm could be possible for parts of the region, followed by a transient cold air mass to start next week.


Tomorrow's Outlook:

With a slightly cooler air mass moving in, temperatures tomorrow will cool down, although remain at least 5 degrees warmer than average across the area. Temperatures will peak in the upper 30s to lower 40s inland and the lower to mid 40s across the rest of the area. Mostly sunny skies are expected along with a light NW wind.


Thursday - Friday: First Storm Potential

With Sunday's update, I mentioned that there are two storm potentials, one on Thursday and another on Saturday. The timing depended on a cutoff low pressure in the southern US, which could either phase on Thursday or on Saturday. The model guidance corrected itself yesterday to show a scenario where the cutoff phases on Thursday, resulting in a larger storm for the region on Thursday night into early Friday, while no storm takes place on Saturday. Some models have attempted to bring up a storm for Saturday, including the 12z GFS, however with the latest trends, there is little support for such a scenario, and the 12z GFS run is considered as an outlier run.


Storm Set Up: The differences with the models for Thursday night have once again narrowed down to the usual differences between the foreign and the American models. The foreign models, consisting of the CMC, UKMET and ECMWF, show a more phased storm further north/west, wetter and warmer, with the CMC bringing temperatures up to 60 degrees for NYC on Friday. The American models, the NAM and GFS, show a much weaker and further southeast storm; although temperatures still get mild on Friday morning on these models, they only do so briefly before cooling down again. The CMC and UKMET are most likely too strong and too warm with the storm, with the CMC even bringing what appears to be a squall line with potential thunderstorms through the area, while the ECM is going with a scenario in between the CMC and the GFS, with locally heavy rain on Thursday night into Friday morning with temperatures rising into the mid 50s across the area. The GFS and the NAM may be a little too weak with the storm, and are slowly trending towards a more phased scenario. As a result, I am leaning towards the foreign models for the scenario on Thursday, which as will be discussed later on, will also affect the outcome for the weekend. I am currently going with a scenario slightly cooler than the ECM to balance out the extreme solutions on either side, although the storm could end up slightly warmer or colder than currently expected.


Forecast: Rain is expected to develop on Thursday evening, lasting through the overnight hours and into the first half of Friday. Going with the scenario mentioned above, temperatures would remain steady on Thursday evening before slowly rising overnight, reaching the 40s across the entire area by Friday morning and the upper 40s to lower 50s in parts of the immediate NYC area and Long Island. Temperatures may slightly warm up on Friday in the late morning into the early afternoon, although skies will clear later on in the day with dropping temperatures.

This scenario is still not final, as there are still going to be some changes with the models. A possible change is for slightly cooler temperatures with rain ending by early Friday morning, not by late Friday morning. Should the CMC/UKMET verify, temperatures would be warmer with heavier rain, although this is a less likely scenario. Stay tuned for more information on this storm.


Saturday - Sunday: Second Storm Potential

With the cutoff low phasing partially on Thursday, the Saturday potential mentioned on Sunday most likely will not verify, with the leftover energy from the cutoff low drifting offshore on Saturday with slightly cooler temperatures. Even if a storm was to come up the coast on Saturday, it would more likely be rain as there is still no strong cold air coming down. By Sunday, however, a stronger trough drops from the north central US with more ridging in the western US. This more amplified scenario will bring a risk of scattered snow showers in parts of the region, potentially including the area. Some models develop a larger storm on Sunday, with the CMC keeping a coastal low pressure slightly offshore while the UKMET has a much stronger storm for the region. The UKMET solution is most likely too extreme, and while any bigger snowstorm is unlikely in this time frame, the potential for light precipitation is there.

Tomorrow's update will discuss the storm potential for Sunday in more details, including the colder temperatures that will follow behind the cold front bringing a colder start to next week.

Monday, January 23, 2012

**No Update Posted 1/23/12**


No update was posted to the blog today. A more detailed update will be posted tomorrow in the evening, including more details on the stormy weather for the end of the week, possibly into parts of the weekend.

Sunday, January 22, 2012

Jan 22, 2012: Freezing Rain Tonight


After yesterday's snowstorm, which dumped anywhere from 3 inches to as much as 12 inches in parts of southern Connecticut, mostly cloudy skies were observed today with temperatures reaching the upper 20s inland and the lower 30s across the rest of the area. A low pressure moving into the Great Lakes region will bring warmer temperatures, but not before resulting in widespread freezing drizzle across the area tonight resulting in light ice accumulations in the interior parts of the area. The storm, however, will end the temporarily colder conditions across the region, with above to well above average temperatures returning for this week.


Tomorrow's Outlook:


Freezing drizzle will continue tonight north and west of NYC, changing over to rain in the immediate north/west suburbs later tonight and in the northwestern parts of the area by Monday morning, resulting in hazardous traveling conditions. With a much warmer air mass aloft, however, temperatures will quickly warm up tomorrow, reaching the mid to upper 40s across the area for highs with parts of the area reaching the lower 50s. A cold front will move through in the evening, bringing a line of scattered showers, with some of these showers potentially including locally heavy rain and/or gusty winds.


Tuesday - Friday: Back To Mild, Rainy Weather


In the Long Range Outlooks section, back on January 14th I mentioned the potential for a warmer pattern between January 20 and 28. Due to yesterday's snowstorm, which was unexpected at that time, the first part of that time frame, January 20-22, ended up colder than average. The intensity of the warmth has been scaled down from the original potential, although starting tomorrow, the next 7 days will bring warmer to much warmer than average temperatures across the region, passing the 50 degree mark twice in the area and the 60 degree mark once in the southern Mid Atlantic. These temperatures are not uncommon in the winter, although they typically last for only a short amount of time, while this winter had temperatures this warm last for longer periods of time while ending up much more frequent than average; in fact, almost half of December had high temperatures near or above 50 degrees, which is much warmer than average.

Behind Monday night's cold front, temperatures by Tuesday morning will still be significant warmer than average. Average low temperatures for this time of the year are in the 20s; low temperatures on Monday night will drop into the mid 30s to lower 40s across the area. The colder air mass coming in behind the front is very weak, and as a result temperatures on Tuesday will warm up into the upper 40s to lower 50s inland and the lower 50s across the rest of the area. Slightly cooler temperatures are expected for Wednesday with mostly sunny skies and highs reaching the mid 40s across most of the area.

By Thursday, a weak storm is expected to affect the region, although details are still uncertain. The ECM and CMC models show little precipitation, while the earlier GFS runs showed more widespread light rain across the area. Cold air is marginal in this time frame, so any precipitation that falls will likely be in the form of rain across the area with perhaps some frozen precipitation falling at some point further inland. The latest GFS run, however, had a stronger storm for Thursday, and while such a scenario is not impossible, for now given the stronger model consensus arguing otherwise, I am considering the 18z GFS run as an outlier. At this time, I am expecting scattered showers across the area with highs in the lower to mid 40s, although the forecast is subject to some changes.


Next Weekend: Another Storm Potential?


There is increasing uncertainty with the models regarding a cutoff low in the southern US in the second half of next week that will bring heavy rain into the southern US, specifically over Texas. This cutoff could phase on Thursday with the Thursday storm becoming the bigger one, as the 18z GFS suggested, although for now this is less likely. Going by the more likely solution of the cutoff low phasing on Saturday, however, a bigger storm potential could be there. Should the cutoff low phase on Saturday, the models that show this, the ECM and GFS, currently have a coastal low, with the 12z ECM showing a significant snowstorm for the interior parts of the area with the GFS keeping the storm mostly offshore. There is still more time for the storm's track to change, should there be one on Saturday, although if phasing does place, given the pattern in place that is the same as the one that's been in place since November, the tendency of cutoff lows in the southern US to phase too far west for the area to see a snowstorm, and the lack of a strong cold air mass in place, I am thinking at this time that an inland storm track would be more likely than a coastal snowstorm. There is time left for changes though, it is possible that there may not be a storm in the weekend, but if there is one, at least as of now a snowstorm does not appear to be very likely given the set up. Stay tuned for more information on the weekend storm potential.


Long Range: Looking Into February

Looking beyond the weekend, some models attempt to bring changes in the pattern; the GFS has been attempting to drop large cold into the US over the last 3 days. The GFS model has attempted to show the pattern changing since the start of December in its longer range, and each attempt failed as the pattern remained in place. Over the last week, there was a temporary interruption in the pattern as strong ridging developed near western Alaska and the polar vortex dropped into southern/central Canada, but as I have mentioned earlier this month when these changes became apparent for the longer range, they were likely to exit just as quickly, and the pattern is already returning back to where it was until now, with a positive NAO/AO, no blocking, an overall progressive pattern and the strong cold air trapped in Canada and Alaska. The MJO is still stuck in phases 4-6 as it has been for most of the last month, a signal that the pattern is still solidly in place as the MJO is still unable to move into phases 8+1, favorable for cold in the eastern US.

With the previously mentioned signals, February is likely on track to be once again near average to warmer than average. Despite this, however, more signals are also pointing to slightly more cold and snow in the region in February and/or March than what the region has seen so far this winter. Having some more cold and snow in February would not be very hard to achieve considering that December ended up nearly 6 degrees warmer than average without any snow in Central Park, and January is on track to end up noticeably warmer than average with only one, potentially two at most, accumulating snow events in Central Park for the entire month. The latest models are already signaling that the EPO may drop towards negative with a slightly rising PNA, although the NAO and AO remain mostly neutral to slightly positive, which although potentially favors slightly better cold/snow chances for the region and isn't a set up for significant warmth, also isn't one for significant cold and snow. At this time, I am looking towards the first 10 days of February for the next potential accumulating snow event for the NYC area; while it is not guaranteed that the area will see accumulating snow at the start of February, it is a possibility, especially if there are some changes in the pattern including a neutral/slightly negative EPO towards slightly more sustained cold in the region. While snow in February and March is not expected to be enough to make the winter snowier than average, it is likely to add to the current winter totals and bring the area's snow totals closer to the average. Stay tuned for more long range updates on the pattern.

Saturday, January 21, 2012

Jan 21, 2012 Storm Updates


Below, storm updates will be posted on the snow event affecting the area.

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11:40 AM: The banding has weakened over northern New Jersey, however it has redeveloped further south, with moderate to heavy snow affecting NYC over the last 1/2 hour before weakening. Light snow will continue over northern NJ over the next half hour before starting to end, adding at least another 1/4 inch of snow. The heavier banding, however, is concentrated over southern Connecticut, where a large stationary band of heavy snow is steadily increasing accumulations. In addition to northern Long Island, which will also see moderate to locally heavy snow, heavier accumulations are expected in these areas, ending up near 5 to 7 inches, potentially even reaching 8-10 inches in some locations. The storm will end in these areas by 1-3 PM, with sleet starting to slowly spread across Long Island by then.


10:30 AM: Over the last hour, a moderate band of snow moved into NYC, while the heavier banding remained stationary from Morris county in NJ to NW Bergen, Rockland counties and southern Connecticut, where a storm total of nearly 5-7 inches of snow is expected. A large dry slot is causing the storm to quickly move out, although the back edge of the storm is filling up on the radar in western New Jersey. Most of central New Jersey south of NYC will only see light snow/sleet from now until 12 PM, although across northern NJ, SE NY and parts of NYC, the light to moderate snow will continue through at least 12-1 PM before ending, bringing at least another 1 to locally 2 inches of snow. The moderate snow will move into the northern half of Long Island and southern CT later on, with snow ending there by 1-3 PM.


9:20 AM: After nearly 3 months since the last snowstorm, a moderate snow event is finally affecting the area, with a weak low pressure bringing widespread light to moderate snow across the region with temperatures still in the upper 10s to lower 20s north and west of NYC and the mid 20s in most of NYC. Widespread accumulations of about 2-4 inches have been reported so far, and will continue to increase over the next few hours.

A dry slot moving through east central Pennsylvania will end the storm much earlier than expected for locations south of NYC, potentially as early as 11 AM, with only light snow afterwards. The heavier banding, however, has been stationary over northern NJ into SE NY and southern CT, with the snow still intensifying in those areas. These areas will end up with the highest accumulations, reaching the 4 to 6 inch range for most locations, locally up to 7 inches. North of NYC, the storm will end by 12-1 PM, with a 1-2 PM ending likely for southern CT. The mixing line slowly continues to advance north through New Jersey, but is only likely to reach parts of NYC and Long Island, especially further south, by the time that the storm ends early in the afternoon.

Friday, January 20, 2012

Jan 20, 2012: Snow Returns Tomorrow


After a weak clipper brought light snow amounts to Long Island and southern Connecticut last night, mostly sunny skies returned for today with temperatures reaching the lower 30s inland. Further east, however, temperatures unexpectedly peaked in the middle of the night in the mid to upper 30s in the immediate NYC area and the upper 30s in Long Island and southern CT, before dropping into the lower to mid 30s by the afternoon.

Cloud cover is starting to increase across the area, however, and for the first time since October, snow will fall tonight into tomorrow without changing over to rain for most places with the first significant snowstorm for the area of the winter months. Snow amounts will be nowhere near those observed with the storms last year, as this will be a weak and fast moving storm, although most of the area is expected to see at least 3 to 7 inches of snow, making this the 2nd significant snowstorm of the entire winter. The brief surge of cold and snow will not last for long, however, as a warm air mass will quickly move in, with temperatures in the 50s, rain and even some possible thunderstorms returning by Monday.


Tonight - Saturday: Moderate Snow


As mentioned with last night's update, a slightly further south scenario appeared more likely, and the scenario I went with for yesterday's update is very close to the final expectation with only a few minor changes in the forecast. The model guidance is also in an overall agreement for at least 3 to 6 inches of snow to fall across most of the area, accompanied by a changeover to sleet in parts of NYC, NE NJ and Long Island by the end of the storm.


Storm Scenario: The low pressure will stay suppressed, moving through West Virginia, into the Washington DC area and then off the coast of southern New Jersey. There is a high pressure to the north of the storm, and with plenty of cold air ahead of the storm, the entire NYC area, even down south to the Washington DC and Delaware/southern NJ areas, will start out with light snow. Throughout the event, warmer temperatures aloft at 850mb will steadily push further north, although the high pressure will help to keep surface temperatures colder, resulting in a more significant freezing rain events for parts of the central Mid Atlantic, including Maryland and southern Pennsylvania. These warmer temperatures will make their way into central NJ and PA, resulting in a changeover to sleet, although by then the storm will be nearing its end, and temperatures aloft may warm up just enough so that at the last hour or two of the storm, the precipitation type changes over to sleet for parts of northeastern NJ, NYC and Long Island. Any sleet, however, will not have significant impacts on the total accumulations for the NYC area since most of the snow will accumulate by the time that the precipitation changes over to sleet.


Forecast for NYC Area: The storm is moving quickly through the Great Lakes right now, with snow expected to start falling in the western parts of the area around 2-3 AM and in the eastern parts around 3-4 AM. Temperatures will be in the upper 10s inland, lower to mid 20s in the immediate NYC area and mid 20s in Long Island/S CT at the start of the storm, allowing the storm to start out with light snow. The snow will intensify throughout the early morning hours, with a widespread moderate snow expected to fall across the area between 6 and 11 AM. As observed in the Great Lakes region and with the short range models showing a slightly heavier band of snow moving through, a brief period of heavy snow may be possible especially in northern NJ/SE NY in the morning hours. With the heavier snow in the morning hours, temperatures are still expected to be in the lower 20s north and west of NYC, resulting in higher snow ratios. Temperatures will steadily warm through the late morning hours, with sleet starting to mix in parts of NE NJ, NYC and Long Island after 10-11 AM. The storm will end by 1-3 PM across the area with cloudy skies afterwards and high temperatures reaching the mid to upper 20s north and west of NYC and the upper 20s to lower 30s in NYC and Long Island.



Total Snow Forecast: This storm does not have a lot of moisture and will be fast moving, so significant snow amounts are not expected anywhere in the region, with any 8+ inch amounts expected to stay isolated at most. For the area, however, with at least 0.5 inch of QPF along with slightly higher liquid to snow ratios, at least 4 to 6 inches are expected to fall across northern NJ, SE NY and southern Connecticut, where the heaviest snow in the area is expected to fall. Slightly lower amounts of 3-5 inches can be expected in NYC and Long Island, where some sleet is expected to mix towards the end of the storm. Locally higher amounts of up to 7 inches may be possible in the northern parts of the area.

Across the region, changes in the snow map were minor for the southern half of the storm from yesterday's map, only slightly extending the accumulations further south, although the 1-2 inch zone based on the latest reports is likely to extend down into Washington DC and southern NJ. More significant changes were made to the northern half of the storm, however, where it appears that less precipitation than previously expected will fall. As a result, the heaviest accumulations of about 5 to 7 inches will be placed from central/northern Pennsylvania into northern NJ, SE NY and into southern CT.

Possible Changes: Although this is the final forecast for the storm, minor changes sometimes take place with the forecast as the storm is ongoing. One potential concern for the storm is that some of the short range models have a dry slot for NYC, with the moderate snow not starting until the later morning hours while surrounding areas see moderate-heavy snow, in which case accumulations for NYC would be lowered and accumulations for locations surrounding NYC would remain the same. Another potential change would be if the storm is overall slightly drier than currently expected. Stay tuned for storm updates throughout the morning hours tomorrow.


Sunday - Next Week: Same Pattern Returns; Warmer Than Average Again


The snow event for tomorrow does not signal a pattern change; instead, the pattern is reversing back to the way it was before a large polar vortex dropped into central Canada a couple of days ago, with the strong cold retreating back to central/northern Canada, where it has been so far this winter. As a result, the pattern starting on Sunday will return to the storm track to the northwest of the area with occasional warmer temperatures returning. This reversal in the pattern has been mentioned throughout the last week, and although the magnitude of the warmth was overestimated at first, there were and still are clear signs that temperatures are likely to end up above average again next week.

After a chilly Sunday, with temperatures in the lower to mid 30s across most of the area, temperatures will steadily rise throughout the overnight hours as a large storm moves towards the Great Lakes region. There may be enough cold air initially that NW NJ and SE NY begin with light freezing rain, although temperatures will warm up later on, with any freezing rain changing over to rain. The warmest temperatures will take place on Monday, reaching the upper 40s to lower 50s across the area, possibly the mid 50s near NYC in the warmer case scenario. A strong cold front will move through, with showers and potentially even some thunderstorms for the afternoon and evening hours, followed by temperatures cooling down a little into the mid to upper 40s for Tuesday. Temperatures will remain mostly above average in the 40s through next week with another storm, more likely rain than snow at this time but still subject to change, by the end of next week.

Thursday, January 19, 2012

Jan 19, 2012: Saturday Snow Forecast


Cloud cover increased across the area today as a weak clipper approached the region from the west, with temperatures reaching the lower 30s inland and the mid 30s across the rest of the area. Light ocean/sound effect snow developed late this afternoon across parts of Long Island and southern Connecticut, with these areas reporting light snow with very light accumulations through the evening. The clipper will quickly pass through the area with only isolated flurries at most, although the focus of the latest forecast is for Saturday, when there are increasing indications that the first significant snowstorm of the winter months will affect the area.


Tomorrow's Outlook:


With the clipper clearing the area tonight, leaving behind a dusting to an inch in Long Island and southern Connecticut, mostly sunny skies are expected across the area tomorrow with temperatures reaching the lower 30s inland and the lower to mid 30s across the area, making tomorrow the second day in a row to feature below average temperatures.


Friday Night - Saturday: First Snowstorm Of The Winter Months


With yesterday's update, I mentioned how a storm was expected to affect the area, with snow likely to start out across the area but changing over to rain, sleet and perhaps freezing rain. Right after my update last night, however, the entire model guidance, even the northernmost models which were consistent with a mostly wet outcome, significantly shifted to the south, favoring a snowstorm across the area. My initial thinking did not turn out to be correct with this storm, complicated by the models' difficulty with handling the storm correctly, although after reviewing the latest models, there is a high confidence level that the area will in fact see its first significant snowstorm of the winter months.

**The scenario map below was made before the latest data came in, so the storm will likely be further south than this map. The snow map in the bottom was adjusted with the latest data.**

The latest models continue to shift south, and as a result, I went with a southern storm scenario map, although the map to the left was made before the latest data came in, so my expectation is for a further south scenario. There is plenty of cold air ahead of this storm, which will lead to the entire area starting out with snow along with temperatures still in the lower to mid 20s north and west of NYC, and in the mid to possibly upper 20s for NYC and Long Island.

Snow is expected to develop across the area between 3-4 AM, with a moderate snow for most places by 7 AM. The storm will quickly move through the region, however it is still expected to produce moderate snow from about 7 AM to 12 PM. Temperatures during the peak of the storm are likely to be in the mid 20s north and west of NYC, and in the mid to upper 20s for NYC and closer to the coast, resulting in slightly higher snow ratios for this storm. The storm will also quickly move out of the area, ending by 1-3 PM across the entire area. Temperatures aloft may warm up enough that sleet could fall at the very end in parts of NYC and Long Island, although the further south the storm tracks, the less likely this would be.

I also went with a further south scenario than most models with my snow map, accounting for any additional slight south trend on the models. Most models suggest at least 0.4" QPF in the form of snow, ranging from 0.3" on the drier models to 0.5" on the wetter models, such as the NAM. Combined with higher ratios, snow amounts may end up in the 4 to 6 inch range across most of the area. The lowest totals are expected to be in NYC and Long Island, where 2 to 5 inches of snow are likely, with higher amounts across northern NJ, SE NY and southern CT, with at least 3 to 7 inches of snow expected.

There is still some slight uncertainty with the storm, and the forecast could slightly change. If any change is made to the forecast, it would be more likely to shift the snow zones slightly further south while keeping the area in the 3 to 6 inch range for snowfall. Stay tuned for more updates on this storm tomorrow afternoon and evening.


Longer Range Update: After cold temperatures on Saturday night, much warmer temperatures will return by Monday as a low pressure tracks well to the northwest of the area, with high temperatures expected to reach the 50s, likely to melt any leftover snow from Saturday's snowstorm. Temperatures will cool back down into the 40s after Monday, with another storm possible towards the second half of next week.

Jan 19, 2012 Noon: Snow For Saturday


4:00 PM: The clipper for tonight is likely to be slightly drier than yesterday's forecast expected, with a widespread dusting to 1/2 inch likely, locally up to 1-2 inches in southern Connecticut. The focus of the forecast, however, is on Saturday, which after an unexpected trend last night where every single model, even those that have consistently showed a mostly wet scenario for the area, suddenly trended south to show a moderate snowstorm for the area. This is only a recent change on the models and is not final yet, although an accumulating snowstorm is now expected for the entire area, with the heaviest accumulations to the north of NYC potentially in the 3 to 5 inch range.

Stay tuned for more updates on this storm throughout the day, including updates to the 5-Day Forecast, Winter, and Weather Alerts pages which will be posted by 5:00 PM. A detailed discussion on the storm including a snow map will be posted this evening.

Wednesday, January 18, 2012

Jan 18, 2012: Tracking Two Snow Potentials


With the cold front moving through the area last night, widespread gusty winds were observed late last night into this morning; immediately after the front passed through last night, wind gusts were in the 35-45 mph range across the area, with windy conditions lasting through the afternoon, gusting up to 30-40 mph across the area as expected. The actual high temperatures today were in the early morning, just before the front passed through, reaching the upper 40s to lower 50s across the area, although temperatures during the afternoon hours were steady in the mid 30s inland, upper 30s to lower 40s in the immediate NYC area, and lower 40s in most of Long Island/S CT. Temperatures are currently dropping across the area, and will reach the lower to mid 10s inland and mid to upper 10s for the north/west suburbs of NYC, Long Island and southern CT by tomorrow morning.

Although the pattern has not changed towards a cold and snowy one, and will not do so any time soon, if it even does so this winter, a set up supporting a favorable storm track with enough cold air will result in two snow potentials for the area over the next several days. Tomorrow night, widespread light snow will fall across the area, with up to 2 inches possible in parts of Connecticut. Saturday, however, will bring a larger storm, bringing a more widespread mix of snow, sleet, rain and possibly freezing rain across the area.


Thursday - Thursday Night: Light Snow Expected


Mostly sunny skies are expected for Thursday morning with high temperatures reaching the lower to mid 30s inland and the mid 30s across the rest of the area. Cloud cover will increase, however, as a weak storm approaches the region from the west. Today's models are starting to emerge on a better consensus, one that involves less precipitation than the wetter models showed. My scenario map yesterday went along with a scenario in between these wet scenarios which no longer appear to be likely, and the dry scenarios showing no snow in NYC which are still supported by a few models. With the latest model trends, I am keeping my outlook the same with only minor revisions to the snow outlook.

My scenario map for the storm can be found with yesterday's update, and above, I posted my expected snow map for the area. Accumulations are expected to reach up to 1 inch in the northwestern parts of the area, but with the storm redeveloping too far east, the immediate NYC area will see the least amount of snow, with a dusting to 1/2 inch, possibly up to 1 inch north and east of NYC. Most of the snow is expected to fall in Connecticut, with widespread 1-2 inches of snow, potentially passing 2 inches in the north/eastern parts of the state. Long Island's forecast is more uncertain; some of the models keep Long Island with snow, while other models show plain rain. Surface temperatures are a bit mild during the event due to onshore winds, and while I do not expect a plain rain event, rain is likely to mix with the snow in parts of Long Island, especially closer to the coast, which should limit accumulations to at least up to 1 inch. A final outlook for the clipper will be posted with tomorrow night's update.


Friday - Saturday: Becoming Stormy Again, Wintry Mix Expected


Cloud cover will briefly clear for Friday with high temperatures reaching the lower to mid 30s inland and the mid 30s across the rest of the area. The dry conditions will not last for long, however, as yet another storm will quickly move through the Great Lakes towards the region, with cloud cover once again increasing by Friday night. With this storm, there is a stronger cold air mass ahead of the storm, and with the models showing some cold air initially, most of the area is expected to start out with light snow. As the low pressure approaches the area, however, temperatures aloft at 850mb are expected to quickly warm up, already ending up above freezing across the area by 12-1 PM. There is still colder air down to the surface, however, with temperatures still stuck in the 30s across most of the area. Some models, especially the NAM, have been suggesting the potential for sleet and/or freezing rain to fall in the interior parts of the area, and this potential will be closely monitored.

The models are showing different outcomes for the storm, with today's NAM runs going with a north and warm storm, with mostly rain for the entire area; the GFS has light snow changing over to rain for most places, the ECM has light snow with up to 1-possibly 2 inches changing over to rain near coastal areas and a mix further north, and the CMC also has a light-moderate snow to rain scneario. The models are apparently getting closer to a consensus, however, with the ECM trending warmer from yesterday's and last night's runs, both of which suggested a moderate snowstorm for most places north of NYC with yesterday's run including NYC in that potential, the GFS fluctuating between slightly colder and warmer scenarios, and the NAM trending south from what started out as a rain storm this morning to what is on its latest evening run modeled to be a snow to ice storm for the northern parts of the area.

With the latest trends kept in mind, the latest 5-Day Forecast was changed to show slightly colder temperatures, especially north/west of NYC, with the mention of sleet/freezing rain inland. The latest expectation is for light snow to fall around Saturday morning, and as the precipitation intensifies, the snow begins to mix with rain across the area, with NYC and places south/east changing to rain by noon. Up until that point, light snow accumulations are possible north and west of NYC; although the exact accumulation is still uncertain, from the latest models, at least 1 inch may be possible, if not more towards NW NJ/SE NY. After 12 PM, the interior parts of the area may mix with sleet and/or freezing rain, although the dominant precipitation type elsewhere will remain as rain. The storm will the end by the early overnight hours.

This scenario is not final yet; the models have not settled on a single solution, and it is possible that tomorrow's outlook may change. A slightly warmer outcome than the above may be possible, although it is just as possible that a colder scenario may be shown with the next outlook, including more snow and less rain. Stay tuned for more information on this storm and its impact across the area.


Tomorrow's update will also discuss the outlook beyond Saturday's storm in more details, including the warmer temperatures returning for Monday.

Tuesday, January 17, 2012

Jan 17, 2012: Some Snow Thursday Night


After last night's update, a widespread mix of light snow and sleet continued to affect most of the area through at least 12-1 AM, when warmer air began to move in and precipitation began to change over to rain. Most places ended up with a coating of snow and sleet, even in parts of NYC and Long Island, although light accumulations of up to 1 inch were observed in Orange county, NY, with up to 2-3 inches in parts of interior southern Connecticut. Temperatures peaked near the upper 30s to lower 40s inland and the mid to upper 40s across the rest of the area, although temperatures are expected to rise into the mid to upper 40s across the area, possibly near 50 degrees in parts of the NYC area, by 12-1 AM as the cold front moves through the area.

Colder temperatures will return into the area behind the cold front, with temperatures tomorrow steady in the mid to upper 30s across most of the area along with windy conditions, gusting up to 30-40 mph late tonight into tomorrow morning. The next storm will affect the area on Thursday night, when a more widespread light snow is likely to affect the area, ahead of another storm on Saturday which is more uncertain but could include some frozen precipitation as well.


Tomorrow's Outlook:


As previously mentioned, windy conditions are expected especially in the morning tomorrow, with winds gusting up to 30-40 mph at times in parts of the area. Partly cloudy skies are expected across the area, with temperatures steady, if not slightly rising, into the lower to mid 30s inland and the mid to upper 30s across the rest of the area, possibly reaching the lower 40s near NYC and parts of Long Island.


Thursday Outlook: Colder, Some Snow


With a high pressure moving towards the region, mostly clear skies are expected on Wednesday night with temperatures dropping into the 10s for most of the area except for parts of Long Island and NYC, which will stay in the lower 20s for lows. Temperatures on Thursday will warm back up into the lower to mid 30s inland and the mid 30s across the rest of the area, although cloud cover will increase as a low pressure approaches the region from the west. This low pressure will produce widespread snow showers across the region on Thursday night, including the area. Most of the snow will fall to the north and northeast of NYC as the low pressure will track north, however temperatures are expected to be cold enough along with enough precipitation to support at least light snow showers for most of the area. Long Island could see more of a borderline situation as onshore winds may be enough to warm temperatures above freezing, resulting in mixing with rain, although some snow is expected in Long Island as well.

There are two main scenarios for this storm right now; the first is where the storm quickly moves through the region with almost the entire precipitation staying north, with light snow affecting NW NJ, skipping through the NYC area with more snow dropping into southern CT/Long Island, in which case NYC would only see isolated flurries. This scenario is supported by some GFS runs and the ECMWF. The second scenario, supported by the CMC and the NAM, is where more precipitation affects the NYC area, with at least 0.1" or more QPF from the immediate NYC area and further north/east. This scenario would bring widespread light snow, with accumulations of 1-2 inches possible in the immediate NYC area into southern Connecticut. Forecasting snow has been difficult this year especially due to the lack of any snow events so far, and the model guidance has not had a good handle on some storms this winter. For now, I am going with a slightly lower snow potential, although it does appear to be likely that most of the area does see snow, and for now I am going with a 60% of snow across the area on Thursday night, with accumulations up to an inch possible. The accumulations are uncertain and subject to change, and could end up higher or lower than expected. Stay tuned for more information on this light snow event.


Friday - Weekend: Another Storm On Saturday


With Thursday's storm moving out, Friday will bring partly sunny skies across the area with breezy winds expected again, with gusts up to 30 mph possible in parts of the area. Temperatures will be similar to those of Thursday, reaching the lower to mid 30s inland and the mid 30s across the rest of the area. Cloud cover will increase again overnight, however, as another storm approaches the region. There is a model consensus for a storm to affect the area on Saturday, although details vary on the models, with the CMC and ECMWF showing a snowstorm for parts of the area and the GFS and NAM/DGEX favoring a further north and warmer scenario. While the southern scenario is possible, the trends this year have frequently been to the north and/or west with storms, and considering that there is not much to prevent this storm from tracking further north, I am leaning towards the northern track scenario, where the storm starts out with some snow in the area but changes over to rain for the rest of the storm, with the majority of the snow focusing over New England, where several inches of snow are possible. This forecast is still not final, as there is some time for changes with the storm, and while less likely, the potential is there that the southern scenario verifies and parts of the area get a snowstorm.

Beyond Saturday, details become more uncertain as the models begin to have more difficulties with handling the set up, although the outlook is likely to remain unsettled through Sunday and into the start of next week, with mostly cloudy skies likely along with the risk of some showers either on Sunday or Monday. Temperatures will warm up as well, reaching the 40s across most of the area for highs. Going forward into next week, however, as my long range discussions over the last week have mentioned, the cold air in Canada weakens and retreats north with a zonal flow in place, and while not the entire time frame will be warm, as some storms will move through keeping temperatures closer to average, although at least once, if not more, temperatures have the potential to reach and/or exceed 50 degrees next week. A more detailed long range outlook, along with an update on February's outlook and whether cold and snow chances will increase or not, will be posted with Friday's update.

Monday, January 16, 2012

Jan 16, 2012: Three Snow Potentials Ahead


9:40 PM Update: Widespread light to moderate snow, mixing with sleet at times, is now falling across northern New Jersey, with moderate snow in SE NY and interior southern Connecticut along with a light rain/snow mix in NYC. A widespread dusting to a coating of snow has been reported in places where snow/sleet is falling, although further inland towards interior SE NY, up to 1/2 inch of snow and sleet has been observed in some cases.

The wintry mix will continue to affect northern NJ and SE NY through at least 10:30 to 11 PM, when a dry slot from Pennsylvania will begin to move in. Until that time, an additional coating to 1/2 inch of snow is expected in interior SE NY and southern CT, with more light snow and sleet on top of the coating observed elsewhere in N NJ and SE NY. Once this round of precipitation ends, temperatures aloft will begin to warm, with the next round of precipitation coming in later tonight falling as rain in most of the area and freezing rain in NW NJ/SE NY.



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The cold air mass that was over the region through last night began to move out, with mostly sunny skies for today along with warmer temperatures, reaching the lower 30s inland, lower to mid 30s in the immediate NYC area, and the mid to upper 30s in Long Island and southern CT. As the radar shows to the left, there is precipitation approaching the area; this precipitation, however, will not start out as rain for most places north and west of NYC; read below for more information on the approaching snow/sleet.


The winter so far has only featured a handful of isolated snow shower events for the area, and while a cold and snowy pattern is not unfolding, there are three potentials for some frozen precipitation to fall across the area; the first is tonight, with widespread sleet from NYC and further north/west this evening before transitioning to rain, with freezing rain towards NW NJ and interior SE NY. In addition to tonight, a weak clipper on Thursday night along with another low pressure on Saturday will bring two additional snow possibilities, although very marginal, to the area.


Tonight - Tuesday Night: Snow/Sleet Tonight, Rain Tomorrow


Temperatures aloft at 850mb have warmed up above freezing across most places west of NYC, meaning that snow is not expected to fall across most of the area except for interior southern Connecticut late tonight. The 925mb layer closer to the surface, however, is decently below freezing, with surface temperatures still near freezing across most places north and west of NYC. Dew points, in addition, are still colder than the surface temperatures, and when the storm moves in around 8-9 PM tonight, evaporative cooling will take place, which along with a small pocket of sub-freezing 850mb temperatures moving in, will allow for widespread light sleet, mixing with light snow, to fall in SE NY, northern NJ and even NYC between 8 PM and 12 AM. Up to a coating of sleet is expected outside of NYC, possibly up to 1/2 inch further north, although the sleet is expected to change over to light rain across the immediate NYC area and southern Connecticut by 12 AM.

By 1-2 AM, temperatures will begin to slowly warm up across the area. surface temperature in NW NJ and Orange County in NY, however, will remain below freezing, setting up for a freezing rain event. Although no significant amounts of freezing rain are expected, with up to 0.1 inch at most, the freezing rain is expected to remain light, making it easier for the rain to freeze on most surfaces and creating hazardous travel conditions. The freezing rain inland is also expected to change over to rain by Tuesday morning.

A break from the rain is likely around Tuesday morning, with a few breaks in the cloud cover possible. By Tuesday afternoon, however, moderate rain will move into the area, lasting through the evening, as temperatures steadily rise into the mid 40s from NYC and further west and the mid to upper 40s in Long Island and southern CT. Temperatures will remain steady until about 12 AM along with isolated showers, with the storm's cold front moving through the area overnight. Temperatures will drop into the 30s towards Wednesday morning along with increasing winds, gusting up to 30-40 mph at times.


Wednesday - Thursday: Colder, Some Snow Thursday Night


Behind the cold front, cooler temperatures are expected for Wednesday, reaching the upper 30s to lower 40s across most of the area with winds still gusting up to 30-40 mph, especially in the morning. Clearing skies are expected overnight as a high pressure moves towards the region, with temperatures dropping into the mid 10s to lower 20s for most places north and west of NYC, with low to mid 20s expected for Wednesday night in NYC and parts of Long Island.

Temperatures will warm up into the mid 30s for Thursday, however increasing clouds are expected as a weak low pressure approaches from the west. Most of today's models have increased the amount of precipitation that falls with this clipper, with the GFS and CMC showing nearly a tenth of an inch of precipitation, which combined with temperatures in the 20s, would result in up to an inch of snow in parts of the area. There appears to be potential redevelopment of the clipper offshore, although there is some uncertainty with this scenario; if it does happen, snow could be enhanced over Long Island with over 0.1" of liquid-equivalent precipitation. The other scenario for this storm is where the clipper is further north, and the majority of the region sees snow except for NYC, which would end up under a dry slot with snow falling to the west and east. Last night's GFS runs as well as the 12z ECM support this scenario. There is still uncertainty, although the potential for snow in parts of the area is increasing, and I placed widespread scattered snow showers across the area in the 5-Day Forecast page, focusing over Long Island. Accumulations are still uncertain, although if the first scenario mentioned verifies, supported by the CMC and GFS, up to an inch of snow may be possible in parts of the area, especially east of NYC. Although this is nothing close to a significant snow event, it has the potential to become the first accumulating snow event for parts of the area. Stay tuned for more information on Thursday night's snow potential.


Friday - Sunday: Warming Up, Some Rain/Snow Possible


Behind Thursday night's storm, a slightly colder air mass will move in, with temperatures once again reaching the mid 30s for highs across most of the area on Friday. Meanwhile, an area of snow is expected to move towards the Great Lakes, with a low pressure moving through the region towards Saturday. Yesterday's models had different solutions, although today's models began to hint on a possible snow event, with the latest 18z GFS as well as both of today's ECM runs showing light snow accumulations for parts of the area. The ECM, however, has shown snowstorms for the area in its medium range several times this winter before losing them as it enters the shorter range, and most storms in the medium range this winter trended north and/or west as they approached the shorter range. The GFS and ECM runs this afternoon already began to trend north, and given the pattern and trends, I expect the storm to trend north of its current position on the models. With cold air ahead of the storm, light snow is possible again in parts of the area, and due to uncertainty, I went with a rain/snow mix across the area, changing over to rain in parts of the area if the warmer scenario verifies. There is still some uncertainty on Saturday's storm potential, however, and it is possible that the storm ends up further south to result in a light snow event, or it could trend north to bring rain for the area with snow again falling in New England. More information will be posted on this potential event as details become clearer.

Looking at the longer range, the addition of the Saturday event along with colder air than previously expected in southeastern Canada is decreasing the probability of a major warm spell across the region; despite this, however, the potential is still there for an unseasonably warm day or two next week. Although some more cold than previously expected is likely for next week, temperatures overall are still likely to average out to warmer than average. Stay tuned for more long range updates, along with updates on the pattern potentially setting up for February.

Sunday, January 15, 2012

Jan 15, 2012: Interior Wintry Mix Tomorrow Night


With a cold air mass moving into the region today, colder temperatures were observed again across the area, with temperatures dropping into the 10s last night before peaking in the lower to mid 20s across the area today with mainly sunny skies. With a high pressure moving in, temperatures are already dropping, and are expected to drop into the single digits for the interior parts of the area tonight. Warmer temperatures will return tomorrow, with a wintry mix inland tomorrow night changing over to rain on Wednesday, and although cooler temperatures will return for Thursday and Friday with isolated snow showers, this cold will only be brief as significant warmth begins to return towards next weekend.


Monday - Tuesday Night: Wintry Mix To Start Inland


Increasing clouds are expected tomorrow with temperatures rising into the mid 30s across most of the area. Temperatures aloft at 850mb will quickly rise above freezing, although surface temperatures will take longer to warm up, resulting in the potential for sleet and freezing rain on Tuesday night towards interior northern NJ and SE NY, although any ice amounts are expected to stay below 0.1 inch.

With warmer temperatures moving in near the surface, warmer temperatures will return by Wednesday with the interior parts of the area changing over to rain in the morning. The low pressure, however, will still be near the Great Lakes on Wednesday while moving NE, meaning that temperatures will only gradually warm up throughout the day, starting out in the mid 30s to near 40 degrees in the morning before reaching the lower to mid 40s inland and the mid 40s across the rest of the area by the evening. The warmest temperatures are expected overnight, towards, 12 AM, when temperatures are likely to peak in the mid to upper 40s across most of the area. The cold front will move through in the overnight hours, with most of the rain expected to end by 2 AM with a total of near 1/2 inch of rain possible. Winds will then increase towards Wednesday morning, gusting up to 30-40 mph. Stay tuned for more information on the interior wintry mix potential.


Wednesday and Beyond:


Temperatures on Wednesday will peak in the upper 30s to lower 40s across the area, although colder temperatures will return overnight, dropping again into the 10s north and west of NYC. Thursday will bring increasing clouds with temperatures reaching the mid 30s as a weak low pressure approaches the Northeast. The best chance of snow will stay to the north of the area with widespread snow showers in the Northeast, although a few snow showers are possible across the area. Some of the models, such as the CMC, ECM and DGEX, have been showing the potential for a coating or more of snow, although until a better consensus emerges, I will keep a chance of isolated/scattered snow showers in the forecast. Friday will bring drier conditions again with highs in the mid 30s due to a colder air mass briefly coming in behind the storm.

Another low pressure may affect the region on Saturday into Sunday, although there are different solutions on the models, ranging from isolated precipitation on the GFS to heavy rain on the ECMWF. Given the latest trends, I am leaning with the GFS and CMC supporting only light, scattered precipitation, although a slightly wetter solution could be possible for this time frame. Temperatures will also gradually warm up into the 40s throughout the weekend, with high temperatures by early next week possibly reaching the 50s. Stay tuned for more information on the longer range.

Jan 15, 2012 Morning Update


11:30 AM: Colder Than Expected For Today

Last night's temperatures were cold across the area, ending up in the lower to mid 10s for most places. Despite full sunshine, however, temperatures are only slowly going up, and the model guidance is continuously correcting itself towards a colder solution for today, with the latest models only showing highs in the upper 10s to lower 20s today. A similar scenario also happened in December with one day where highs were originally expected to be in the mid to upper 30s but only ended up near 30 degrees, and given the latest observations, it is reasonable that highs end up colder than expected today.

With sunny skies, the expectation for today is for highs to end up in the upper 10s to lower 20s degrees across NW NJ and SE NY and the lower 20s across the rest of the area. Temperatures may get close to 25 degrees in some areas near NYC.

Saturday, January 14, 2012

Jan 14, 2012: Colder Tomorrow, Warmer Monday


A line of scattered snow showers developed this morning, as mentioned with this afternoon's update, and affected northern New Jersey to NYC and western Long Island from the late morning until just half an hour ago with scattered snow showers, some of these briefly moderate. Most locations in northern NJ to NYC saw flurries, although between about Warren through Morris and into Hudson counties in NJ, a band of light snow stalled through most of the afternoon, with some areas picking up a coating of snow. The snow has shifted to the south of the area, however, and with the snow staying south, skies will clear later tonight with much colder temperatures returning by tomorrow morning.

Cold temperatures are expected for Sunday again, although a warmer air mass will once again return by Monday and Tuesday, with above average temperatures expected to return. A weak low pressure will move through the region, bringing widespread rain on Tuesday and Tuesday night with temperatures in the 40s, though the potential is there for the storm to start out with a light wintry mix with little to no accumulations in NW NJ and southeastern NY. Colder temperatures will briefly return for the end of next week with a light snow shower potential for Friday, although the set up that develops beyond this time frame may bring some of the warmest temperatures the area has seen so far this winter into the longer range.


Tomorrow's Outlook:

With the cold air mass moving into the area, cold temperatures are expected tonight, dropping into the lower to mid 10s across most of the area except for parts of the immediate NYC area, which will see warmer temperatures in the upper 10s to possibly the lower 20s. Mostly sunny skies are expected for tomorrow along with cold daytime temperatures, peaking in the mid to upper 20s across the area.


Next Week: Warmer, Some Rain

The cold air mass will quickly be pushed out on Monday with warmer temperatures once again returning, reaching the upper 30s to lower 40s across most of the area. An approaching storm will bring cloudy skies overnight along with a warmer air mass moving in, which will result in temperatures only slightly dropping overnight before rising towards Tuesday morning. There may be enough cold air left at the start of the storm that NW NJ and Orange County in NY start out with a wintry mix, although if this does happen, little to no accumulations are expected, which would be followed by a quick changeover to rain. Occasional showers will continue on Tuesday and Tuesday night with high temperatures warmer than average but still relatively chilly compared to what we've previously seen this winter, reaching the lower 40s inland and the lower to mid 40s across the area, with showers ending before Wednesday morning as a colder air mass moves in. Wednesday will be dry with temperatures reaching the mid 30s for highs across most of the area.

A colder air mass will temporarily move into the region for Wednesday night into Friday, with Wednesday night bringing low temperatures back into the 10s for most of the north/west suburbs of NYC and southern CT. Clouds will increase again on Thursday, however, as a low pressure approaches the Northeast, with high temperatures reaching the mid 30s again across most of the area. Mostly cloudy skies are expected on Thursday night with light snow across the Northeast, and while most of the precipitation will stay to the north of NYC, isolated rain or snow showers are possible especially in the northern parts of the area. Temperatures are likely to warm back up into the 40s for Friday.


Longer Range: The outlook for the longer range has not changed since yesterday, with increasing warmth and temperatures likely to gradually rise into the 40s and later on the 50s during the weekend and into early next week. In the Long Range Forecasts page, I posted yesterday's long range discussion but with a few additions; with the set up potential for the medium range, the potential is there for temperatures to pass 60 degrees in the area at least once, if not more than that, in the 1/20 to 1/28 time frame. Stay tuned for more long range updates.