Monday, December 31, 2012

Dec 30, 2012 Brief Update

Forecast Overview:

The region will be under a cold and generally dry pattern for the next week, with few notable upcoming weather events. Aside from a few flurries on New Year's Eve and on January 1, most of the week will be dry. Until Tuesday, highs will be in the 30s, with highs in the mid 20s to low 30s expected for the rest of the week. The coldest day is expected to be next Friday, with highs in the 20s for most of, if not all of the area, with widespread lows in the 10s likely, possibly slightly below 10 degrees for interior northern areas. A moderation in temperatures is expected towards next weekend with the possibility for some precipitation but no major storm likely at this time.

The next full discussion and updated 5-day forecast will be posted on Monday, 12/31.

Saturday, December 29, 2012

Dec 29, 2012 Storm Updates

Updates will be posted on the rain and snow event currently affecting the region. A few detailed updates will be posted in the bottom of this post, with most updates from Twitter.

Live storm updates will be posted on Twitter occasionally throughout the day.

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

Blog Updates:

3:55 PM: Since the last update, the coastal low affected the area, with moderate accumulations observed in NW parts of the area. Towards NYC and NE NJ, however, this is busting on the low side, with rain in NYC resulting in barely any accumulations, while a persistent dry slot in NE NJ just west of the banding with the coastal low prevented locations from picking up much more than an inch. Long Island has seen rain so far, although a changeover to snow is expected as the coastal low intensifies, with heavy snow expected for some areas.

With the latest observations, the totals have been again revised. For NW NJ and SE NY, 2 to 5 inches are still expected. In NE NJ, 1-3 inches are expected, with less than 2 inches in NYC and western Long Island. Higher totals are expected in eastern Long Island due to heavy precipitation from the coastal low tonight with parts of the island picking up 2-4 inches, with the highest totals in the area in eastern and central CT, where at least 4 to 8 inches of snow are expected, with locally higher totals above 8 inches towards eastern CT.

12:10 PM: Since the last update, the coastal low has continued to intensify, and is currently a 1002 mb low near eastern North Carolina moving NNE. Precipitation associated with the coastal low continues to expand and intensify, and moderate to heavy snow is moving into the area, mixing with rain in parts of Long Island. Heavy snow rates are expected up to 1/2 to 1 inch per hour especially west and north of NYC for the main part until the storm ends.

Forecast accumulations have been slightly raised to 1-3 inches in Long Island, 2-4 inches in NYC, 3-5 inches in NE NJ and SE NY, and 4 to 7 inches in southern CT. Locally higher totals may be possible.

10:30 AM: The snow from this storm has been affecting Pennsylvania and New York throughout the morning, although most of the area has been dry so far. Last night's update mentioned the potential for a drier area to set up near the Interstate 95 corridor southwest of NYC in between the interior snowfall and the developing coastal low, which is what is currently happening, only that the dry conditions are reaching NYC and extending into southeastern New York. Precipitation from the developing coastal low is currently intensifying over Washington DC, and will reach the area late this morning through the afternoon hours.

Currently, temperatures are currently cold enough to support snow across most of the area, with 925mb temperatures ranging from 0C in eastern LI to -4C in NW NJ, and 850mb temps near -3C to -5C across the area. A southeast wind persists at 925mb, however, with the low still near western Pennsylvania, and 925mb temperatures will continue to rise. With that said, some of the models were already too warm for this morning, showing NYC and Long Island in the upper 30s when temperatures are only near 33-34 degrees for most, and may be overdoing the warmth at 925mb and thus the northern extent of the rain/snow line as well. The current forecast for today is still for plain snow north and west of NYC, perhaps mixing with rain at times towards Newark; snow occasionally mixing with rain in NYC and western LI; and mostly rain for eastern and coastal Long Island.

At this time, my thoughts on snow accumulations have not changed, although locally higher totals are expected across the area, especially in Connecticut. Below is an updated version of my regional snow map posted yesterday on Twitter:

Dec 28, 2012: Saturday Snow Forecast

Forecast Highlights:

After an unusually mild December, a winter pattern gradually began to spread through the US starting mid December, and will reach the NYC area starting tomorrow with a snow and rain storm expected for the area tomorrow. Behind this storm, a sustained cold pattern will develop going into the first week of January, with very cold temperatures possible as well as a few snow shower potentials, one of them on New Year's Day.

Friday, December 28, 2012

Dec 27, 2012: Snow Expected For Saturday

Forecast Highlights:

The gradual turn to a cold pattern continues through the forecast period, with no warmth in sight through the next week. Following yesterday's storm, drier conditions returned today and will continue on Friday, with the next storm affecting the area on Saturday with widespread moderate snowfall. Behind the storm, much colder temperatures are expected for next week with the first period of sustained near to below average temperatures since November.

Wednesday, December 26, 2012

Dec 26, 2012 Storm Updates

Updates will be posted on the rain, snow, ice and wind event currently affecting the region. A few detailed updates will be posted in the bottom of this post, with most updates from Twitter.

12 AM: An update has been posted on the weekend storm and the potential for changes in the forecast with a significant snowstorm possible. Scroll down for more information.

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

Blog Updates:

12:00 AM: While most of the event has ended for the area, a last strong batch of heavy rain is moving through the area, and is expected to produce strong to damaging wind gusts, up to and locally over 60 mph. Today's storm has had many impacts on the area; ranging from power outages further south due to the strong winds, heavy rain near NYC, and significant snowfall in the northwestern parts of the area, which are still reporting snow but are expected to mix with and gradually change over to rain, sleet and freezing rain.

**Forecast Update**: Behind this storm, yet another snow event is expected for the region, this time including more of the area without a changeover to heavy rain. A relatively weak storm will quickly move towards the region, with snow expected throughout the day on Saturday as it moves towards the coast and intensifies offshore. At this time, most models are relatively weak with the storm, but there are signs of a trend of a slightly stronger and wetter storm. The current expectation based on the latest model trends is for a light-moderate snowstorm to affect the area with snow totals generally between 2 and 5 inches, although it is not out of the question that a snowier scenario with a stronger and more amplified storm ends up being shown with future model runs; if so, forecast totals may need to be adjusted upwards for parts of the area with later updates, and a more significant snowstorm may be possible. More information will be posted on this with Thursday night's discussion.

9:00 PM: Over the last few hours, the snow in the immediate NYC area gradually mixed with and changed over to sleet and rain; currently, rain is the dominant precipitation type in NYC and further east and south, with southern Connecticut and NE NJ near the borderline, switching between rain and sleet. Heavy rain, mixing with sleet occasionally north of NYC, will continue until at least 12 AM, with only light occasional showers expected afterwards. Strong wind gusts will continue tonight, with lighter winds expected tomorrow.

Heavy snow continues to affect NW NJ and interior SE NY, with heavy snow and strong winds resulting in near blizzard conditions at times. Accumulations of 4 to 8 inches are expected prior to the end of the bulk of the storm, with freezing rain expected to begin mixing later tonight. Plain rain is also expected to start mixing but not until the bulk of the storm ends, when precipitation is lighter and more spotty.

5:40 PM: Since the last update earlier this afternoon, snow has developed from NYC and further north/west, with rain and some snow/sleet in Long Island. Moderate to locally heavy snow was observed in N NJ and SE NY, with accumulations generally in the 1-3 inch range so far. Especially towards NE NJ and NYC, precipitation has been going back and forth from snow to rain/sleet, but is expected to transition towards more sleet and rain as the rain/snow line, currently close to the Interstate 80 corridor, continues to slowly shift north.

Additional accumulations are expected in SE NY, southern CT, north central and NW NJ through the evening hours while NYC and NE NJ gradually change over to plain rain, with sleet, freezing rain and rain gradually reaching the northwestern areas as well this evening. For the immediate NYC area into Long Island and southern CT, once the changeover takes place, heavy rain will continue through at least 12-4 AM with up to an inch expected, along with wind gusts up to 50-60 mph, perhaps locally higher in Long Island.

Following the weakening of the primary low pressure over Kentucky, the secondary low pressure is developing as expected near SE Virginia, and will move NNE towards New Jersey and just south of NYC by tonight, although most of the precipitation will fall ahead of the low pressure.

2:40 PM: This morning, the storm produced light accumulating snow for Baltimore, with the rain/snow line currently set up near the Interstate 95 corridor with flurries observed from NYC and further west and SW. Light non-accumulating snow is expected in NYC, changing over to rain by at least 5 PM. West of NYC, the snow is expected to pick up in intensity through at least 5-6 PM, when the rain/snow line will gradually move from northeastern NJ further north/west, gradually making its way towards NW NJ and interior SE NY where more ice is expected towards the overnight hours. The current accumulation forecast is for 1 inch in NE NJ, 1-2 inches in SE NY, 2-4 inches towards western Bergen county and interior Rockland county, and 4-8 inches in NW NJ and interior SE NY, with locally higher amounts possible.

Dec 25, 2012: Final Storm Forecast

Forecast Highlights:

An active pattern continues for the region following a light rain/snow event last night, with a major storm currently in the southern United States making its way towards the Northeast, and is expected to produce heavy rain, strong winds, significant snowfall and ice across the region from Wednesday afternoon through early Thursday. A brief break is expected for Friday before another storm affects the region on Saturday with light snow.

Tuesday, December 25, 2012

Dec 24, 2012: Two Storms, Then Cold

Forecast Highlights:

A weak and fast moving light snow event affected the region tonight, with less than 1 inch of snow for most of the area, locally higher, with more snow than expected in NYC and Long Island. With the minor accumulations, enough snow will remain on the ground for some to experience a white Christmas. This is just the first storm of this new wintry pattern, however, as a significant storm on Wednesday produces heavy rain, wind as well as snow and ice inland, followed by another storm potential next weekend.

Monday, December 24, 2012

Dec 24, 2012 Storm Updates

NOTICE: Pattern Outlook #7 has been posted this evening, and can be found below this post.

Updates will be posted on the light snow event currently affecting the region. A few detailed updates will be posted in the bottom of this post, with most updates from Twitter.

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

Blog Updates:

6:30 PM:The first snow event since November 27, almost a month ago, is affecting the region tonight. Observations from the Mid Atlantic show the storm has overperformed with the extent of the snowfall, with bursts of heavy snow reported east of the Interstate 95 corridor while accumulations have been reported along and west of I-95, with some locations seeing up to 2-3 inches of snow. While the precipitation is slightly weaker than it was in the Mid Atlantic, the potential is there that there is more widespread front end snow than expected, extending into NYC and parts of Long Island as well. With the warmer surface temperatures, however, accumulations will be limited to locations north and west of NYC, with up to an inch expected for the north/west suburbs and 1-2 inches for the interior NW parts of the area.

Long Range Pattern Outlook #7

Brief Overview:

Today's long range pattern outlook focuses on the medium range pattern going into early January, with growing indications that the pattern changes evolving during late December continue into early January with a cold pattern for the region, possibly including several snowstorms as well, one of them on December 29-30.

Click below to read the full post.

Dec 23, 2012: Three Storms Coming Up

Forecast Highlights:

Following Friday morning's cold front, mostly cloudy skies were observed on Sunday with windy conditions and isolated snow flurries; weaker winds were observed on Sunday. Chilly temperatures will continue until Monday night, when two storm potentials are expected for the region. At least some snow is expected north and west of NYC on Monday night, with a more significant storm on Wednesday into Thursday that will produce heavy rain, wind, as well as snow and freezing rain for the interior.

Sunday, December 23, 2012

Dec 23, 2012 Noon: Brief Update On Storms

This post covers the planned update for yesterday, 12/22. Two posts will be added tonight, a pattern outlook and an additional discussion on the upcoming storms.

Monday Night - Tuesday: Christmas is shaping up to be wet rather than white for most of the area, although parts of the area still have a chance to make it to Christmas morning with snow on the ground. Light precipitation will develop early on Monday night, ending by Tuesday morning; this will be mostly, if not entirely rain from NYC and further south and east, with light snow quickly changing over to rain for the north/west suburbs with a longer period of light snow for the interior northwest parts of the area. Accumulations will be limited to north/west of NYC, with up to 1 inch possible for the suburbs and 1 to 2 inches towards NW NJ and interior SE NY.

Wednesday - Thursday: The model guidance is still not consistent with the storm mid-late next week, with the GFS having gone all the way from a coastal low with a major snowstorm in NYC to a low pressure over Ohio with heavy rain and 50 degrees for the area. The 18z GFS run last night showing this outcome is likely a western outlier, just as the 18z GFS run 2 nights ago with the major snowstorm is also an outlier. For now, I'm making little revisions to my original thinking, going with a slightly more west track and a warmer outcome with the low pressure tracking over or not far west of New York City. Most of the area is likely to see plain rain, with some snow to start changing over to rain north and west of NYC as well. The exact timing is uncertain at this time, but appears to be mostly a Wednesday night event into Thursday. The main risk at this time appears to be heavy rain over 1 inch and strong winds, although some accumulations are still possible further inland towards NW NJ and interior SE NY.

These storms will be discussed in more detail tonight, along with another storm potential towards the end of the month. A pattern outlook focusing into early January will be posted as well.

Saturday, December 22, 2012

Dec 21, 2012: Winter Begins With 2 Snow Potentials

Forecast Highlights:

While the start to winter has been delayed, unlike last year winter has not been denied; the heavy rain and wind event today marks the transition to an actual wintry pattern, starting off with snow showers and strong winds across the region tonight and tomorrow, followed by chilly temperatures. The effects of this change will become even more noticeable next week, with two snowstorm potentials expected for the region, one which may result in a white Christmas for parts of the area.

Friday, December 21, 2012

Dec 21, 2012 Noon Update

4:55 PM: Last night, the area was affected by a heavy rain and strong wind event. Widespread gusts of 45-60 mph were observed along with rainfall generally up to 1 inch as temperatures surged well into the 50s for some. Following the cold front, temperatures have dropped, and are currently in the upper 30s to low 40s west of NYC and in the low to mid 40s from NYC and further east. Winds will pick up again with the strong upper level low over the region, with gusts up to 40-50 mph expected again on Saturday along with scattered snow showers, especially towards interior western areas where a coating of snow may be possible.

The December limited posting schedule of one discussion in 2-3 days has ended yesterday. Daily discussions and updates, including a daily 5-day forecast update, will resume starting tonight. More information on the upcoming wintry pattern, including two snow potentials, will be posted tonight.

Wednesday, December 19, 2012

Dec 19, 2012: Rain Thurs Night, Then Cold

*Correction: The headline was edited to fix a typo expecting rain tonight instead of Thursday night.

Forecast Highlights:

Following heavy rain and even some thunderstorms on Monday night into Tuesday, conditions are briefly drying up across the region for Wednesday and Thursday. This period of calm weather will be short lasting, as a stronger storm affects the region on Friday with heavy rain, wind and isolated flurries while a cold air mass settles over the region until about Christmas or the day afterwards, when the next storm is set to affect the region.

Monday, December 17, 2012

Dec 17, 2012: Rain Tonight, Thursday Night

Note: The current limited posting schedule with 1 discussion in 2-3 days will end late this week. The typical daily posting schedule will resume next weekend.

Forecast Overview:

Today - Tuesday: Following the departure of the overnight showers, another round of rain is expected on Monday night, with mainly cloudy skies and highs in the low to mid 40s inland and mid to upper 40s elsewhere on Monday. Light to moderate rain is expected overnight with locally heavy showers possible. Rain totals are expected to generally end up around 1/2 to 3/4 inch for most with locally higher totals possible. Temperatures will reach the upper 40s to low 50s inland and the low to possibly mid 50s for the rest of the area on Tuesday with mostly cloudy skies and increasingly windy conditions from the NW.

Wednesday - Friday: Wednesday will be another windy day but with mostly sunny skies, as high temperatures reach the mid 40s inland and the upper 40s for the rest of the area. Lighter winds are expected for Thursday with highs slightly warmer than those of Wednesday. By Thursday night, a strong low pressure will move into the Great Lakes region, with temperatures overnight steadily rising into the low to possibly mid 50s across the area while moderate to locally heavy rain affects the area with the cold front. Once the front moves through, temperatures will quickly cool down by the morning hours into the 30s west of NYC and 40s in NYC and north/east, with mostly cloudy skies and windy conditions for Friday with highs in the 40s for most.

Longer Range: There is still some uncertainty regarding what happens in the longer range with the late week storm, with the latest model guidance keeping the upper level low suppressed over the region with a strong block to its north, which would result in several days of near to colder than average temperatures, with highs in the 30s and lows in the 20s, starting on Saturday. At this time, a cold and dry Christmas appears likely, with a storm potential afterwards. Stay tuned for more information on the longer range.

Saturday, December 15, 2012

Dec 14, 2012: Three Storms Next Week

Forecast Highlights:

Following a generally inactive and mild first half of the month, some changes in the pattern are currently developing with less sustained mild temperatures, and at least in the short to medium range more storminess as well. This will be most noticeable next week with three storms expected; at this time, rain or a wintry mix is favored over a snowstorm, especially for the first two storms, but the potential is still there for at least one snow event to affect the area before the end of the month.

Wednesday, December 12, 2012

Dec 11, 2012: More Active Pattern To Return

Forecast Highlights:

Following last night's cold front, cooler temperatures returned with highs in the mid 40s inland and the upper 40s to low 50s for the rest of the area, which was warmer than expected. Similar conditions will continue through Saturday until a more active pattern develops, with rain expected on Sunday and Monday with another potential storm around the 19-20th.

Monday, December 10, 2012

Long Range Pattern Outlook #6

Brief Overview:

Tonight's long range pattern outlook focuses on the medium range pattern going into the second half of the month, as some changes in the pattern do not result in a much colder pattern but do increase the probability of seeing at least one snowstorm by the end of the month.

Click below to read the full post.

Sunday, December 9, 2012

Dec 9, 2012: Rainy Start, Dry End To Week

Forecast Highlights:

Showers have been observed across the area today as temperatures are currently starting to climb, and will peak in the low 60s near NYC for the third time this month tomorrow behind a stronger cold front. Temperatures will cool down significantly on Wednesday before slowly rising throughout the rest of the week ahead of another rain event towards next weekend into early next week.

Dec 8, 2012: Warmth, Rain Early This Week

Forecast Highlights:

A cold front is currently moving through the area, although rain will redevelop again on Sunday as a warm front moves through the region, with warmth returning briefly for Monday before another cold front overnight. Temperatures will warm up again throughout the rest of the week with dry conditions ahead of another rain event likely late next weekend or early the following week.

Thursday, December 6, 2012

Dec 5, 2012: Rain Returns Weekend, Next Week

Forecast Highlights:

Following another unseasonably warm day on Tuesday, slightly colder but still above normal temperatures returned today (Wednesday) behind a cold front, with chilly temperatures sticking around through Thursday night. The cool temperatures will only be short lasting, however, as a warmer air mass returns for the weekend into early next week with persistent cloud cover and occasional showers, peaking on Monday into Monday night as another cold front moves through the region.

Tuesday, December 4, 2012

Dec 3, 2012: Little Cold, Snow Through Mid Month

Forecast Highlights:

As soon as meteorological winter began two days ago, the winter-like pattern in November fell apart, with a short lasting surge of warmth providing the region with widespread 50 and 60 degree weather through Tuesday for most and Wednesday for some areas further east. While cooler temperatures will return behind a cold front on Tuesday night, they will not be long lasting, with a warmer than average pattern with little snow chances continuing through at least the middle of the month as more clouds and rain return for parts of the weekend and especially early next week.

Sunday, December 2, 2012

Dec 1, 2012: Fall-Like Start To Winter

Forecast Highlights:

The region has been under a cold pattern for the last week of November, with the 2nd snowstorm of the month on the 27th. Following another cold day today, a warm front is moving through the region, removing the cold air mass from the region as much warmer temperatures briefly return. Behind a cold front on the 5th, temperatures will cool down briefly before returning to slightly above average, with stormy weather potentially returning by the 9-11th.