Friday, November 30, 2012

Final Winter 2012-2013 Outlook

This is the only winter outlook posted this year; there was no preliminary outlook. Last year's final outlook can be found here. As with the last 2 years, an updated winter outlook will be posted in early January.

Final Winter 2012-2013 Outlook
NYC Area Weather

For the second consecutive year, winter is already off to an early start for the NYC area. Only a year after last year's historic late October snowstorm, a significant snowstorm affected the area on November 7th this year with another minor snowstorm on the 27th, as this November ended up with the coldest monthly temperature anomalies for the area since early 2011. The early October snowstorm was as close to a winter as last year got in terms of snow, however; a mild, snowless and progressive pattern persisted through the entire season, resulting in one of the warmest and least snowiest winters on record. While the winter will be off to a somewhat mild start, unlike last year, there are already significant differences that will prove this year to be different than last year with more cold and snow, potentially even above average.

Tuesday, November 27, 2012

Nov 27, 2012 Evening Update

5:25 PM: Storm Ending West Of NYC

The second snow event of the month affected the area today, with snow totals as of earlier this afternoon mostly below 2 inches north and west of NYC into southern CT, with the highest totals towards western and central NJ away from the coast with as much as 3-5 inches of snow. NYC and Long Island mostly observed rain with little to no accumulations.

As the latest radar shows to the left, the storm is currently moving out of the area, with rain and snow ending from NYC and further west over the next 1-2 hours. Precipitation will persist through the early overnight hours for Long Island and southern Connecticut as the coastal low, currently south of Long Island, intensifies while moving away from the region. Temperatures will drop into the 20s tonight north and west of NYC, with low 20s further inland and mid to upper 20s for the north/west suburbs of NYC including parts of southern CT. Chilly temperatures will stick around through Friday, with warmer temperatures returning for the weekend and into early next week. More information on the forecast will be posted with a brief update tonight.

Monday, November 26, 2012

Nov 26, 2012: Tuesday Rain/Snow, Then Cold Again

Forecast Highlights:

After warmer temperatures for the area today, cloud cover will be on the increase tonight as a fast moving low pressure approaches, producing the second snow event for the month mostly focusing west and southwest of NYC. Behind this storm, temperatures will cool down for the second half of the week, but will not last for long as a warmer pattern develops for the first week of December, possibly beyond.

Sunday, November 25, 2012

Nov 24, 2012: Weak Storm For Tuesday

Forecast Highlights:

Following last night's cold front, a much colder air mass resulted in colder temperatures and windy conditions across the area, with isolated snow showers observed in some areas especially north and west of NYC. This colder pattern will last through the end of the month; while no significant storms are expected for at least the next 2 weeks, the main highlight will be a fast moving low pressure producing a light rain/snow event for Tuesday.

Friday, November 23, 2012

Nov 23, 2012: Light Rain/Snow Likely Tuesday

Forecast Highlights:

The stable pattern with little variation in temperatures that has been in place since last Tuesday is coming to an end with a cold front moving through the region tonight, producing scattered showers north of NYC with much colder temperatures for this weekend. A stormy pattern is unlikely to develop through the start of December, although a weak storm will affect the region during the middle of this week with light rain and snow likely. Click below to read tonight's forecast discussion.

Thursday, November 22, 2012

Nov 22, 2012: Storm Possible Next Week

Forecast Highlights:

After what has been a long stretch of dry conditions through the middle of the month, with most of the area at least 25-50% of the average monthly rainfall, a change in the pattern is expected, although at least for the next 2 weeks is not expected to result in any stormy pattern. The next upcoming precipitation event is possible for the middle of next week, with a storm expected to reach the region but with the track still uncertain.

Long Range Pattern Outlook #5

Brief Overview:

Tonight's long range pattern outlook focuses on the end of November into early December, regarding the medium range pattern and an expected pattern change, along with verification for the 2nd pattern outlook from 10/16. The final winter outlook will be posted next Tuesday.

Click below to read the full post.

Wednesday, November 21, 2012

Nov 20, 2012: Winter Approaches; Storm Next Week

Forecast Highlights:

Three more days of mostly to partly sunny skies and similar temperatures are expected in time for Thanksgiving day, with dry conditions and highs in the low to mid 50s expected. By this weekend, the pattern will begin to change as the cold air that has been building up in Canada drops into the US more frequently, starting with a much colder weekend followed by a storm around the middle of next week.

Tuesday, November 20, 2012

Nov 19, 2012: Mostly Sunny Thanksgiving, Colder Weekend

Forecast Highlights:

Temperatures will continue to gradually warm up slightly throughout this week, with partly sunny skies expected for Thanksgiving along with highs in the low to mid 50s. The zonal and dry pattern in place will begin to change starting this weekend with a transient cold air mass expected, with the next widespread storm potential expected around November 27-29.

Sunday, November 18, 2012

Nov 17, 2012: Pattern Lasts Through This Week

Forecast Highlights:

The drier pattern that has been in place since Wednesday will fail to break apart through the medium range, with a high pressure keeping dry conditions and little variation in temperatures sticking around through Sunday and the rest of the upcoming week as a coastal low pressure remains suppressed to the south and east. Beyond Friday, however, changes will begin to take place in the pattern leading up to December, starting with a likely cold spell around next weekend.

Saturday, November 17, 2012

Nov 17, 2012 Evening Post

The blog will be updated tonight with a forecast discussion and a new 5-Day Forecast. Brief updates will be posted until Tuesday due to my busy schedule, with the current posting schedule, in effect through December, to be resumed on Wednesday.

Blog Announcements:

1. The hurricane Sandy and early November storm summaries will be posted by late November.

2. Pattern outlook #5 will be posted on Tuesday, 11/20. This outlook will discuss the pattern through early December, including a verification of pattern outlook #2, as well as a preview of this year's winter outlook.

3. The 2012-2013 winter outlook is currently scheduled to be posted on Tuesday, 11/27.

Thursday, November 15, 2012

**No Updates Posted 11/14-16, 2012**

Due to a very busy schedule, I will not be able to update the blog tonight and tomorrow. The next update will be posted on Saturday, 11/17/12.

Wednesday, November 14, 2012

Nov 13, 2012: Cooler Temperatures Continue

Brief Forecast Overview:

Following this morning's cold front which brought widespread showers, a colder air mass returned into the region today, with chilly temperatures sticking in place through the rest of this week into most of next week. In this time period, high temperatures will generally remain in the mid 40s to low 50s across the area. Lows will start out tonight in the mid 20s to low 30s away from NYC, with mid 30s in NYC and the immediate coast, although will gradually warm towards the weekend and next week into the low to upper 30s away from NYC, with upper 30s to low 40s in NYC and the immediate coast. Mostly to partly sunny skies will continue through the weekend.

The forecast becomes more uncertain next week with a coastal storm, with some models keeping the storm south of the region while others show rain reaching the Northeast. With the pattern in place, this storm will generally be slow moving; increased cloud cover and possibly rain are expected for early-mid next week, with the storm likely to exit the region towards late next week. Stay tuned for more information on this storm potential and the possible impacts in the area.

Tuesday, November 13, 2012

Nov 12, 2012: Chilly, Drier Pattern Coming Up

Forecast Highlights:

Following another warmer than average day, a cold front is currently moving through the region, with a chilly air mass returning by Tuesday. Chilly temperatures will continue through the next 1-2 weeks without any significant warmth or cold, while a coastal storm may affect the region next week, especially in the Mid Atlantic and potentially in the Northeast, with additional rain possible.

Forecast Overview:

As the radar image above shows, a cold front is moving through the region with widespread showers. The rain should clear most of the area by the late morning except for the eastern half of the area, with colder highs expected for Tuesday peaking in the mid to upper 40s inland and the upper 40s to low 50s across the rest of the area. Dry conditions will persist through the rest of the week and into next weekend with little changes in the weather conditions across the region; highs will generally reach the mid 40s to low 50s for most days, with lows in the mid 20s to low 30s away from NYC, ending up slightly warmer by next weekend into early next week.

As mentioned with yesterday's pattern outlook, a more progressive and less amplified pattern will develop, with above average 500mb heights across the northern US with below average heights in the Southeast along with a potential coastal storm around early-mid next week. With the above average heights and a strong surface high pressure to its north, the low will remain suppressed, and at this time would be most likely to have possible impact in the Southeast, possibly extending further north into the Mid Atlantic. Frozen precipitation is not out of the question for interior parts of the region should precipitation make it this far north, but with an absence of widespread strong cold air which remains bottled up in Canada, this storm is unlikely to be a widespread snow producer. With the pattern in place, this is likely to be a slow moving storm, influencing the pattern across the region through at least mid next week. No significant change in temperatures appears to be on the way through at least late next week.

Monday, November 12, 2012

Long Range Pattern Outlook #4

Brief Overview:

Tonight's long range pattern outlook focuses on the second half of November, regarding the medium range pattern and the potential for a coastal storm, along with verification for the 1st pattern outlook from 10/6. The final winter outlook will be posted towards late November.

Click below to read the full post.

Sunday, November 11, 2012

Nov 10, 2012: Warmer, Less Extreme Pattern Ahead

Forecast Highlights:

Following the extreme 10-day period ranging from hurricane Sandy to extreme cold and a significant early season snowstorm, the NYC area is finally getting a much needed break from the active pattern. A pattern change is currently unfolding, with much warmer temperatures returning this weekend into early next week as a less active pattern continues through at least the middle of November.

Nor'easter Brief Summary:

For the 2nd year in a row, the NYC area was affected by an unusually early significant snowstorm, with widespread amounts of 4 to 10 inches, locally as high as 13-14 inches, observed. This storm was very difficult to forecast with the model guidance failing to reach a consensus on the storm scenario until the storm was already underway. While parts of the forecast from the night before did verify, such as the expectation for a widespread snowstorm across New Jersey, SE NY and CT, the heavy snow began earlier than expected, with the heavy snow axis east of the expectation as totals were much higher than expected. Parts of Long Island which were expected to receive rain ended up with as much as 4-8 inches of snow, parts of Connecticut and New Jersey received as much as 10-14 inches of snow, and even Central Park received 4.7 inches of snow; this makes this month the snowiest November since 1989 which also had 4.7 inches, tying it with that year as the 6th snowiest November on record; the top 5 snowiest Novembers in recorded history were all from 1938 and earlier.

Latest Forecast: Drier, Not As Cold

Fortunately, there is not much to say about the upcoming pattern which remains relatively calm, bringing a much needed break to the region after Sandy, unseasonable cold and an early snowstorm. A strong ridge is currently building over the eastern half of the US, with a much warmer air mass spreading into the region. This will result in a significant warm up as temperatures reach the upper 50s to mid 60s on Sunday and the low to mid 60s, locally upper 60s near NYC, on Monday. A cold front will move through the region on Monday night with scattered showers as a colder air mass returns behind it, with highs returning into the upper 40s to low 50s for most of the area on Tuesday, followed by more widespread lows in the upper 20s to low 30s away from NYC. These colder temperatures will continue through at least Thursday, with a gradual warm up late in the week into next weekend as highs return into the mid to potentially upper 50s range. The main highlight towards the medium range is the potential for a storm around next weekend or early next week, which remains uncertain at this time.

Thursday, November 8, 2012

Nov 7, 2012 Storm Summary

November 7, 2012 Snowstorm

On November 7, 2012, a moderate snowstorm affected the NYC area with moderate to locally heavy wet snow. Typically, a storm of this magnitude is not unusual, with numerous bigger storms observed over the last few years. This event, however, was made notable due to several factors, including this being the second year in a row the NYC area observed an unseasonably early snowstorm, unusually difficult forecasting of the storm even 1-2 days in advance, and this wet snowstorm coming barely a week after hurricane Sandy devastated the Mid Atlantic coast.

Wednesday, November 7, 2012

Nov 7, 2012 Storm Updates

Updates will be posted on the nor'easter and unusual early season snowstorm currently affecting the area starting later this afternoon. A few brief Twitter updates will be posted before then, with blog updates on the storm starting in the late afternoon as well.

10:20 AM: concern growing for heavy snow this afternoon to begin a bit earlier than expected with accumulations a bit higher in the NYC area. Update will be posted at 11:40.

Latest Twitter Updates:  (Scroll to the bottom of the post for blog updates)

Blog Updates:

11:20 PM: The snow band impressively continues to hold in place over the NYC area, although it has slightly weakened over the last few hours and has become a bit more broken up. Regardless, this storm has significantly overperformed in terms of snow totals, with widespread totals of 5-10 inches, locally up to 12 inches, likely across parts of New Jersey, NYC, western Long Island, and western/central CT, with the highest totals over SW CT.

This is the last storm update for tonight. The snow will gradually weaken later in the overnight hours, with dry conditions expected by the morning. The next forecast update will be posted on Thursday evening.

7:50 PM: The heavy snow band continued to train over the immediate NYC area over the last few hours, with accumulations as high as 6-8 inches reported in SW Connecticut. Precipitation from the nor'easter has dried up across parts of the Northeast, although the band of heavy snow remains strong over the immediate NYC area, with lighter snow observed in NW NJ, Orange county in interior SE NY, and eastern Connecticut and Long Island. Additional power outages are being reported with the snowstorm on top of locations that remain without power due to hurricane Sandy a little more than a week ago, while winds were weaker than expected, generally reaching 40-50 mph in Long Island. The snow is expected to begin weakening after 8-9 AM, gradually ending through the overnight hours.

5:30 PM: A highlight of the winter came quite unexpectedly before the season even started, and in the strangest of all situations possible: A significant early season snowstorm in the NYC area a little more than a week after a late season hurricane in New Jersey. The current set up is somewhat east of yesterday's forecast, the northwestern parts of the area are underperforming, with Sussex and Orange county likely to end up with 1 to 3 inches total, with the lowest totals further northwest.

Instead, the heaviest snow is focusing in the area over NE NJ, NYC, western Long Island into Nassau county, and southwestern/central Connecticut, where the storm is significantly overperforming. Totals of at least 4 to 8 inches are expected across most of this area. The latest radar shows banding over NYC, Nassau county and SW CT, with the heaviest storm totals possible towards CT where amounts as high as 10 inches may be possible in some areas.

Current conditions will generally continue through the evening, with weakening snow likely towards the late evening and early overnight hours, with lighter snow mixing with light rain later into the overnight hours with temperatures staying close to the freezing mark. Mostly cloudy skies with isolated rain/snow showers are expected  for Thursday with slightly warmer temperatures, peaking in the low to mid 40s across most of the area.

1:30 PM: As of the latest observations, the heavy precipitation band is now near western Long Island and SW CT, approaching NYC and the north/western suburbs. Once the band crosses NYC, heavier snow will develop in the immediate NYC area for the rest of the afternoon into the evening hours while moderate to heavy snow continues in western Connecticut. The snow will continue through the evening hours before starting to weaken.

The updated snow map has been posted below. The heaviest snow totals will be across north central and NE NJ into SE NY and western Connecticut, where totals above 4 inches are expected. Isolated locations may see as much as 7 to 9 inches of snow under the heaviest bands.

11:45 AM: As expected, snow is starting to affect the immediate NYC area with some areas also reporting rain. The main  change in the expectation, however, is that the period of heavy snow originally expected for late this afternoon into the evening looks to end up a bit east of the original expectation while also moving in earlier than expected, affecting the immediate NYC area into central NJ and SW CT with moderate to heavy wet snow as early as 1-2 PM, even in NYC. This could be a big issue for locations where snow accumulates on the roads, with hazardous driving conditions for the afternoon and evening commutes.

At this time my forecast accumulations are similar to my map from last night but slightly adjusted upwards, with up to 1-2" likely in parts of NYC, and widespread 3-4+ inch totals across northern NJ, SE NY and SW CT, starting from the north/west suburbs of NYC. Totals may be as high as 6-8 inches in some areas.

Nov 6, 2012: Snow and Wind Expected Tomorrow

Forecast Highlights:

As the nor'easter that has been significantly complicated by unusually large differences in the model guidance approaches, there remains some confusion regarding exactly what it will end up doing, with the latest model guidance just 12 hours before the storm still not showing signs of agreement regarding the exact solution. Despite the uncertainty, there is more confidence that the area is dealing with a moderate to significant nor'easter tomorrow with strong winds for the coast and a wet snowstorm for interior parts of the area. Click below to read the latest analysis for the nor'easter.

Tuesday, November 6, 2012

Nov 6, 2012 Noon Update

The science of weather forecasting is not perfect. Storms are not always certain to follow a specific solution even in the short range prior to a storm's arrival; typically, the model guidance narrows a range of a storm down to a reasonable expectation within at least the 3 day range, allowing  for a high confidence forecast to be made, but in some cases, there continue to be differences within this range with lower confidence. This has happened in the past few years on numerous occasions, including the 12/26/10 blizzard and the 10/29/11 snowstorm. Typically, I take the conservative route to wait for more data, but sometimes I take a risk and make a forecast that's bolder and which I think has the higher chance of being closer to reality.

In this case, the risk I took with the forecast backfired. The model guidance has had an extremely poor handling of this storm, and even now, less than 2 days away from the storm, still can't get the set up right and continues to vary with the handling of the storm. After every model shifted east last night, the model guidance is back to being inconsistent, with most models shifting back west while some remain well to the east; while the models have had large short range trends as mentioned with the two examples in the top, there was already a growing model consensus 48 hours out; the models rarely change this much while within the 48 hour range as we are seeing with the current storm. As such, my latest forecast focuses less on the model guidance trends and more on the recent observations.

My preliminary forecast at this time, one which I do have a bit more confidence with than yesterday but still not a high confidence forecast, is for the low to end up closer to the coast but not as close as the discussion 2 days ago showed. Many of the points from that discussion will be brought back into tonight's final forecast as well, which will include a longer discussion focusing on the observations of the storm, comparing them to today's different model outlooks, and attempting to narrow the forecast down to a single scenario, clearing up the confusion from last night and earlier today.

With the latest thinking, coastal areas look to suffer the most, with strong wind gusts of 50 to 60 mph, perhaps higher in some areas, which along with coastal flooding will bring back many issues to the same places still devastated by Sandy which are struggling to recover. While the coastal flooding is not expected to be as significant as it was with Sandy, that region is already left more vulnerable to the impact of coastal flooding following Sandy.

The biggest change from Sunday's forecast discussion, however, is the snow outlook. Heavy precipitation is expected to move into the eastern Mid Atlantic region, likely from Delaware into New Jersey, which along with marginal boundary layer and mid level temperatures, is likely to result in a band of moderate to heavy wet snow in places that typically do not receive snowstorms in early November, which in this case includes most of New Jersey, perhaps eastern Pennsylvania, into the NYC area and parts of southwestern New England. Even the Jersey shore and NYC may see some mixing with snow, although at this time very little, if any accumulations are expected in the coast. Snow accumulations are uncertain, but the potential is there for at least 2 to 5 inches of wet snow in the areas that fall under the heaviest snow in New Jersey.

Stay tuned for additional updates this afternoon and evening for the final forecast, and if any changes are to be made to the forecast above. Coastal areas are still highly recommended to pay close attention to this storm and the recent developments.

Nov 6, 2012 Morning Update

Nov 6, 2012 Morning Update

This is very unusual, and an unprecedented move on my part, but I had to remove my forecast discussion from last night. The model guidance is almost never this inconsistent - in the nearly 3 years I had this blog, and before that as well, the model guidance was never this inconsistent with an expected storm just 1-2 days prior to the event. After every single model trending and staying east last night, this morning's models are trending back west just as quickly.

Stay tuned for more information as I post additional updates on this frequently changing situation. An update will be posted at noon, focusing less on the model guidance and more on the observations.

Monday, November 5, 2012

Nov 5, 2012 Noon Update

5:00 PM: Confidence remains low on the forecast as some of the models that have been the most consistent with a significant nor'easter are backing down and shifting east, towards less impact in the region. The latest GFS run significantly changed from its previous runs and keeps the storm almost entirely east of NYC with less winds as well. Forecasts usually aren't this uncertain within the 2 day range ahead of an approaching storm - for now I kept the 5-day forecast similar, but slightly lowered probability of precipitation west of NYC. Tonight's forecast will be posted at 1:30 AM, following the rest of tonight's model runs, to have a better idea of what the storm might do. Stay tuned.

1:20 PM: Since yesterday's update, there have been significant changes with the model guidance regarding the nor'easter on Wednesday and Thursday. Some of the models are much more east, such as the NAM and UKMET, although they are likely outliers and are expected to trend back west. The CMC model has the storm intensifying much further south, with some snow in Virginia and Maryland along with moderate rain and strong wind gusts in the NYC area; the GFS and the 12z ECM, however, show a moderate wet snowstorm for the eastern Mid Atlantic up through eastern Pennsylvania and most of New Jersey, even including NYC.

Confidence in the forecast is currently lower than it was yesterday as the models continue to change around, with the main changes involving the precipitation type and the intensity, although wind gusts are still expected to be strong for the area, especially for the coast with wind gusts near or above 50-65 mph expected for Wednesday night into Thursday, which along with some coastal flooding will result in even more issues for the coastal areas struggling to recover from Sandy. Stay tuned for a detailed forecast discussion this evening reviewing today's trends along with a new, updated forecast.

Long Range Pattern Outlook #3

Brief Overview:

Tonight's long range pattern outlook focuses on the first half of November, regarding the medium range pattern and the warmer pattern developing, along with the November outlook. The final winter outlook will be posted towards late November.

Click below to read the full post.

Sunday, November 4, 2012

Nov 4, 2012: Rain, Wind Return This Week

Forecast Highlights:

Colder temperatures will continue to affect the area over the next few days with highs in the 40s to low 50s and lows in the 20s to mid 30s, which will be an issue for areas without power and heating still struggling to recover from the devastating impact of hurricane Sandy. The dry conditions won't last for long, however, as a nor'easter affects the region on Wednesday into Thursday with additional rain, wind, and even snow for interior areas, with additional wind and coastal flooding for the coast. Click below to read the full post.

Saturday, November 3, 2012

Nov 2, 2012: Nor'easter Expected Next Week

Forecast Highlights:

As the NYC area enters its fifth day after the devastating hurricane Sandy, the weather pattern offers little improvement over the next week. A sustained cold pattern will continue for the next several days, with highs in the 40s and lows in the 20s to mid 30s becoming an issue for places without power and heating. Following the cold, a nor'easter is expected to affect the region next week with additional rain, wind and snow, although not nearly to the extent of Sandy. Click below to read the full post.

Thursday, November 1, 2012

Nov 1, 2012: Cold Weekend; Storm Possible Next Week

Forecast Highlights:

The devastating impacts from hurricane Sandy continue to affect the region three days since its landfall in New Jersey; although some places have regained power, many others still remain without power. Unfortunately, the upcoming weather pattern is not helping the hard hit areas from Sandy, as places without power will have to deal with a cold weekend with highs in the 40s to low 50s and lows in the 30s, which will additionally be followed by the potential for a storm next week. Click below to read the full post.