1:45 PM | ****Accumulating snow threat increases for Saturday following likely record-breaking cold on Friday morning****

[12Z GFS forecast map for early Saturday afternoon (blue=snow); map courtesy "tropicaltidbits.com"]

Discussion

The Friday morning extreme cold The coldest air mass of the season is flowing into the region today on strong NW winds and low temperatures by early Friday could very well be in record territory up and down the I-95 corridor. Sub-zero lows are possible early Friday; especially, in the normally colder suburban locations of the big cities along the I-95 corridor. The record low for Friday at Philly International Airport is 1 degree above zero and that daily record is in jeopardy. The record at Reagan National Airport in Washington, DC seems to be an easy one to reach at 8 degrees (above zero) which has amazingly held since 1896 (when temperatures were measured downtown at 24th and M St.). Not only are record low temperatures quite possible tomorrow morning in the I-95 corridor, but it could turn out to be the most extreme cold in this area since January 1994. That winter (1993-1994) featured numerous severe ice storms in the Mid-Atlantic region and there was one incredible cold air outbreak during the second half of the month that followed significant accumulations of ice and snow. If DC manages to set a record low on Friday, it will be the first time it has done so in any winter month since 1994 (source: Washington Post/Capital Weather Gang).

The Saturday snow threat A large area of moisture is headed our way this weekend and it looks like it will arrive during the day on Saturday in the form of snow and accumulations are quite possible. Eventually, advancing warmer air will likely cause a changeover of the snow to sleet and/or freezing rain and perhaps even to plain rain in parts of the I-95 corridor. However, before the snow changes to sleet and/or freezing rain, it is possible for snow accumulations to occur in much of the region from DC-to-Philly-to-NYC on the order of a few-to-several inches. The snow should arrive in the DC metro region during the morning, mid-day-to-early afternoon in Philly, and by late afternoon in the NYC metro region. There will likely be a period of icing late Saturday or Saturday night - at least in DC and Philly - before any possible changeover to plain rain ever takes place (NYC could stay as all snow). The milder conditions on Sunday will quickly be followed by another Arctic blast by early next week and more accumulating snow may threaten the Mid-Atlantic region by the middle of next week.

Stay tuned on the weekend precipitation event – a complex forecast.

6:00 AM | ****Incredible cold right into Saturday with sub-zero temperatures possible in the I-95 corridor...could be the coldest air mass since January 1994****

[Record or near record lows this morning in a widespread area; map courtesy "coolwx.com"]

6-Day NYC Forecast

Today

Brutally cold today with mostly cloudy skies and a few more snow showers are possible, temperatures will struggle to reach the upper teens and strong winds will generate sub-zero wind chills

Tonight

Incredible cold with partly cloudy skies, still windy with painfully cold sub-zero wind chills, lows by morning near 0 degrees or even slightly below

Friday

Fierce cold with partial sunshine, windy early, but diminishing winds during the afternoon hours, highs may not surpass the 15 degree mark

Friday Night

Another incredibly cold night with partly cloudy skies, calm conditions, lows by morning in the low-to-mid (positive) single digits

Saturday

After a bitter cold start, skies will become cloudy and snow is possible late in the day, temperatures will moderate during the afternoon with highs late in the day near 30 degrees; snow may mix with sleet or freezing rain overnight, but accumulations of snow are likely before the mixing

Sunday

Any mixed precipitation early in the day is likely to change to plain rain, milder, low-to-mid 40’s

Monday

Partly sunny, colder again, windy, upper 20’s

Tuesday

Partly sunny, very cold, mid 20’s

Discussion

Another blast of Arctic air is flooding into the Mid-Atlantic region and this could turn out to be the most extreme of all this winter. There are widespread record or near record lows this morning in the eastern half of the nation and records are likely in many locations during the next couple of mornings. A few examples from this morning across the Midwest include Chicago, IL at -8 degrees which is a record for the date, -11 degrees at Mount Vernon, IL which is a record for the month, and Cape Girardeau, MO at -18 degrees which has tied their all-time record low.

Temperatures around here today will be confined to the upper teens for highs and strong winds will generate sub-zero wind chill values. There can still be some snow shower activity today as the Arctic air continues to pour into the region. Temperatures in the overnight hours will likely drop to zero degrees or slightly below in many parts of the I-95 corridor which would be record-breaking territory. After a bitter cold day on Friday, temperatures should drop to single digits by early Saturday morning, but then the trend will be up for temperatures - at least temporarily. In fact, by Sunday afternoon high temperatures should get back to rather seasonal levels with highs in the 40’s ahead of yet another Arctic blast which will arrive early next week. There can be some snow late Saturday as the milder air advances into the region and then the snow is likely to mix with sleet and freezing rain in the overnight hours, but not before some snow accumulations take place. Any mixed precipitation early Sunday is likely to change to plain rain as temperatures climb on Sunday afternoon towards the 40's.

Video

httpv://youtu.be/HMchQWFULjs

3:25 PM | ****Snow showers/snow squalls this evening to usher in record-breaking cold for the eastern US on Thursday/Friday****

[Latest NEXRAD radar image showing snow bands setting up to the west of the I-95 corridor; map courtesy University of Wisconsin]

Discussion

Snow showers/snow squalls The coldest air mass of the season so far is plowing towards the eastern US and its arrival this evening will generate snow showers and snow squalls in the I-95 corridor. Just like the previous Arctic frontal passage this past weekend, heavy snow bursts can quickly have an impact on visibility and road conditions and a coating to an inch of snow accumulation can take place in a hurry. The arrival of the snow is likely around 5-7PM in DC, 7-9PM in Philly and 9-11PM in NYC, but the threat for snow showers will continue well into the night and there can actually be more snow showers on Thursday.

Record-breaking cold As far as temperatures are concerned, this air mass is likely to break many records in the eastern US between Thursday and Saturday with sub-zero low temperatures likely in much of the I-95 corridor; especially on Friday and Saturday mornings. In fact, in many parts of the I-95 corridor, this cold air outbreak could produce temperatures not seen around here since January 1994. All of this is courtesy of an air mass that crossed over the North Pole from Siberia and is about to pounce on the eastern US. Temperatures moderate noticeably late Saturday after a bitter cold start to the day and they could actually surpass 40 degrees in much of the I-95 corridor on Sunday before yet another Arctic blast occurs early next week.

[Lower atmosphere (850 mb) temperature anomalies for Thursday; map courtesy Weather Bell Analytics]

7:00 AM | ***Another powerful Arctic frontal passage to spark snow showers this evening and possible heavier snow squalls...brutally cold air will follow for Thursday into Saturday...sub-zero temperatures possible with this next Arctic blast***

6-Day NYC Forecast

Today

Sun followed by clouds, still quite cold, snow showers possible at the end of the day, highs in the upper 20’s

Tonight

Snow showers, possibly a heavier snow squall or two, a coating to an inch of new snow accumulation is possible along with slick spots on roadways, turning breezy and brutally cold by morning with lows in the lower teens

Thursday

Bitter cold with considerable clouds, windy, occasional snow showers still likely, highs only reaching the upper teens

Thursday Night

Downright fierce cold with possible sub-zero temperatures by morning (perhaps even record-breaking), partly cloudy skies, still windy with painfully low wind chills

Friday

After a possible sub-zero start continued bitter cold with partial sunshine, windy, highs only reaching the middle teens

Saturday

Mostly cloudy, still quite cold, but not as harsh, chance for snow late in the day and a mixed bag of precipitation possible at night, near 30 degrees

Sunday

Mostly cloudy, milder, chance for mixed precipitation becoming all plain rain, low 40's

Monday

Partly sunny, colder again, mid-to-upper 20’s

Discussion

Another powerful Arctic front is approaching the I-95 corridor and it is likely to spark some snow shower activity from this evening and there can be a heavier snow squall or two. In fact, it is not out of the question that there be a quick coating to an inch of snow given the strong upper-level energy that is associated with this surface frontal system. Once this front passes through the region, incredible cold Arctic air will flood the region. The period from late tonight into early Saturday will be frigid indeed with amazing low temperatures each morning – possibly even sub-zero and record-breaking come early Friday. Saturday starts off very cold, but it’ll turn milder late along with the chance for some snow. By Saturday night and Sunday, it should become mild enough for a mixed bag of precipitation to change to all plain rain with highs on Sunday surpassing the 40 degree mark before yet another cold air mass arrives for the early part for next week.

7:00 AM | ***Winter's worst weather continues with more snow and incredible cold including sub-zero temperatures***

6-Day NYC Forecast

Today

Snow winds down by late morning then remaining mostly cloudy and very cold, highs this afternoon in the low 20's

Tonight

Partly cloudy, very cold, lows in the mid-to-upper teens

Wednesday

Mostly cloudy, still quite cold, snow showers likely in the late afternoon, possible heavier snow squalls, mid 20’s

Wednesday Night

Snow showers early with a possible snow squall, a quick coating to an inch of new snow possible along with slick spots, becoming brutally cold, lows by morning in the upper single digits

Thursday

Bitter cold with partial sunshine, highs only reaching the low-to-middle teens

Friday

Possible sub-zero start to the day, bitter cold with partial sunshine, highs only reaching the middle teens

Saturday

Partly sunny, not as harsh, chance for snow at night, upper 20’s

Sunday

Mostly cloudy, milder, chance for rain, ice or snow, mid-to-upper 30’s

Discussion

This stretch with the worst weather that winter has to offer will continue over the next several days with more snow and incredible cold including possible sub-zero low temperatures. Now that the latest snowfall is winding down in the NYC metro region, attention turns to the next important weather event. Indeed, another powerful Arctic front will arrive late tomorrow and it is likely to generate late afternoon and early evening snow showers along with a possible heavier snow squall. In fact, this frontal passage could produce a quick coating to an inch of new snow later tomorrow and early tomorrow night and there can be slick spots on the roads as a result. Incredible cold pours in behind the front for Thursday, Friday and Saturday. Low temperatures will bottom out at extremely cold levels during that stretch with single digits likely on Thursday and Saturday morning's and sub-zero temperatures - possible record-breaking - likely on Friday morning. More snow is possible by late Saturday, but as the weekend progresses, the temperatures will climb to levels which will allow for the possibility of precipitation other than that in the form of snow.

Video

httpv://youtu.be/qwsSY00SdTA

1:30 PM | ****Snow on the way****

Discussion

No significant changes from the morning timetable and snow accumulation estimates…snow has begun in the last hour in Charlottesville and Culpeper in Virginia - just to the southwest of DC - and it should arrive in the DC metro region between 3 and 6pm. The snow will hold off until after the evening commute in the Philly metro region not arriving until 6-10pm. In NYC, the snow will hold off until late tonight likely not arriving up there until the 12am-4am time period. Accumulations by mid-day Tuesday still look higher in the southern and eastern portions of the I-95 corridor region with 6-9 inches likely in the area from DC to the (southern) Jersey Shore, 4-7 inches in and around Philly (the higher amounts to the south and east, the lower amounts to the north and west), and 2-5 inches in the NYC metro region. Snow showers and snow squalls are possible late Wednesday as another brutally cold Arctic invasion arrives. Thursday and Friday will be downright frigid with possible record-breaking cold.

7:00 AM | ***Fierce cold this morning, accumulating snow from later tonight into mid-day Tuesday...more brutal cold follows later this week which could produce temperatures not seen here since Jan 1994***

6-Day NYC Forecast

Today

Sunshine giving way to late day increasing clouds, frigid, after a start near zero degrees, temperatures will struggle to reach the upper teens

Tonight

Snow develops late this evening and continues in the overnight hours, very cold, lows near 10 degrees

Tuesday

Snow in the morning with total accumulations by mid-day in the 2-5 inch range, very cold, low 20’s

Tuesday Night

Mostly cloudy, very cold, middle teens

Wednesday

Mostly cloudy, breezy, very cold, snow showers likely at times, possibly a snow squall, additional small accumulations possibble, mid-to-upper 20’s

Thursday

Brutal cold and possibly even record-breaking, partly sunny, middle teens for highs

Friday

Brutal cold and possibly even record-breaking, partly sunny, middle teens for highs

Saturday

Partly sunny, cold, near 30 degrees

Discussion

Winter will put on quite an amazing display this week and here is a quick summary: frigid cold this morning with temperatures near zero degrees will be followed by accumulating snowfall from later tonight into mid-day Tuesday; snow showers and snow squalls should take place late Wednesday with additional small accumulations possible, and that will be followed by record-challenging cold on Thursday and Friday.

Today starts off on the frigid side with temperatures near zero and they will struggle this afternoon to reach the 20 degree mark. Snow will break out later today likely in the midnight-3am time period and continue right into mid-day on Tuesday. The total snowfall accumulation range in the NYC metro region will likely be 2-5 inches by early afteroon on Tuesday. This snowfall will have serious implications on the Tuesday morning commute, school openings, etc. Another Arctic blast arrives late Wednesday likely accompanied by snow showers/snow squalls and additional small accumulations, and then record-challenging cold on Thursday and Friday which may even surpass this morning's fierce cold for its severity.

10:30 AM | ****Accelerated accumulating snow threat - now set for late Monday into Tuesday****

[Record or near record lows from early Sunday; courtesy "coolwx.com"]

Discussion

I should have known better. Tomorrow is President’s Day and this particular holiday has a way of attracting snowstorms (e.g., 1979, 2003). What was once looking like an accumulating snow threat for the time period of Tuesday into Wednesday is now looking like a serious threat for late Monday into Tuesday. In fact, anywhere from a few-to-several inches of snow is looking possible now from late Monday into Tuesday in the I-95 corridor region from DC-to-Philly-to-NYC with perhaps the threat for the heaviest snowfall in the DC metro region. This snow event could certainly have serious implications on the Tuesday morning commute, school openings, etc. Preliminary snowfall estimates by Tuesday mid-day are as follows: 6-10 inches in DC, 4-8 inches in Philly, 3-6 inches in NYC.

Today’s "slap-in-the-face" Arctic cold in the Mid-Atlantic region ensures that this next event will be an all-snow event. Low temperatures in the overnight hours will drop to 0 degrees or even slightly below in many I-95 corridor locations to start the new work week and the scary news is that the same extreme type of cold could happen again later in the week. Records will be challenged in many Mid-Atlantic locations on Monday morning as well as on Thursday and Friday mornings of this upcoming week. Another brutal cold Arctic outbreak - perhaps even colder than the current blast - will follow behind the next storm with the second half of the week featuring widespread, extreme and sustained bitter cold across the eastern US. Incredible stuff.

[5-day temperature pattern from today through Thursday...brutal cold in the eastern half of the nation; courtesy WSI]

8:30 AM | ****Incredible looking overall long-term pattern: afternoon/night accumulating snow with heavy squalls, damaging winds late tonight/early Sunday with possible power outages, painful cold on Sunday, multiple additional snow threats and brutal cold air outbreaks****

[Early morning NEXRAD radar image with snow over the Great Lakes/Ohio Valley and headed our way; image courtesy University of Wisconsin]

Discussion

The next 24-36 hours will bring us accumulating snow with heavy squalls, high impact winds, painful cold and dangerous sub-zero wind chills as a result of tremendous intensification of a storm system off the Northeast US coastline. This storm is currently located over southeastern Ontario and it will drop rapidly today towards the I-95 corridor region. Once this system reaches the coastal waters it will deepen explosively by some 36 millibars in a 24-hour period. The combination of the relatively warm waters of the western Atlantic Ocean, an extremely vigorous upper-level wave of energy, and a powerful upper-level jet streak will help cause this rapid intensification during the next 24 hours or so. This type of rapid and significant intensification will lead to a very sharp pressure gradient across the Northeast US which, in turn, will lead to extreme wind gusts on the order of 55 mph or so in the period between late tonight and Sunday morning (approximately 3 am to noon). Unfortunately, power outages are quite possible with this type of wind from late tonight into early which is the same time the coldest air of the season comes pouring into the region. Winds will slowly decrease later Sunday afternoon and evening.

As far as the snow is concerned, while there can be some snow seen this morning, the majority of the snow showers and possible heavier snow squalls should occur this afternoon and continue this evening. The snow part of this event will really consist of two parts: one part associated with the Arctic front from this afternoon into the late evening hours and then the second part associated with the developing storm late tonight and early Sunday. Some of the snow squalls this afternoon and evening can be quite intense with brief heavy snowfall, gusty winds, very poor visibility ("white out" conditions) and quick accumulations. Late tonight and early tomorrow will pose another chance for additional snowfall from eastern PA northeast across New Jersey and New York City as the storm deepens rapidly off the coastline. In fact, New York City could end up with its heaviest snowfall during this latter portion of the storm when an “inverted trough” extends to the northwest of the intensifying surface low pressure center. One final note on the snow, it is possible that some "thunder snow" occurs during the next 24 hour in portions of the I-95 corridor given this tremendous upper-level suport and upward motion in the atmosphere.

Accumulations by tomorrow morning are likely to be in the 1-3 inch range across Philly, a coating to 2 inches in the DC metro region, and 2-5 inches in and around NYC metro region. However, we'll have to watch for a potential surprise late tonight and early Sunday for additional snowfall in the Philly metro region and especially in the New York City metro region which could add to these preliminary accumulation estimates. Much of the snow that does accumulate will be whipped around by powerful winds late tonight and on Sunday with considerable blowing and drifting possible in some areas. Temperatures are likely to drop to single digits by early tomorrow throughout the I-95 corridor, then struggle to rise at all during the day, and then plunge to possible record-breaking territory by early Monday morning in the area of 0 degrees or even slightly below.

Another system could throw significant accumulating snow our way late Tuesday into early Wednesday, but that storm track is still somewhat uncertain. However, what is quite certain is that there will be more bitter cold air for the second half of next week and beyond and there will be multiple additional snow threats as an unbelievable long-term pattern is shaping up for the Mid-Atlantic region.

7:00 AM | ****Weekend accumulating snow, painful cold, dangerous sub-zero wind chills with potentially damaging wind gusts to 55 mph or so****

6-Day NYC Forecast

Today

Mostly sunny, windy, bitter cold, highs in the middle teens with sub-zero wind chills

Tonight

Partly cloudy, winds die down rapidly to calm conditions, very cold, lows in the lower teens

Saturday

Thickening clouds, becoming windy, cold, but not as extreme as today, snow developing during the afternoon hours, upper 20’s

Saturday Night

Occasional snow, becoming extremely windy, bitter cold by morning, snow accumulations by late night on the order of 2-5 inches with blowing and drifting of snow after midnight, low temperatures not far from 10 degrees

Sunday

The coldest day of the year so far…snow still possible early, painfully cold, extremely windy with dangerous sub-zero wind chills, potential damaging wind gusts to 55 mph or so, considerable blowing and drifting of snow, highs struggle to reach the lower teens

Monday

A bitter cold start near 0 degrees; mostly sunny, breezy, still very cold with afternoon highs struggling to reach 20 degrees

Tuesday

Becoming cloudy, quite cold, snow possible late in the day or at night, upper 20's

Wednesday

Snow possible, windy, cold, upper 20's

Discussion

Arctic air has arrived and today promises to be a brutally cold day despite plenty of sunshine along with sub-zero wind chills as winds remain quite strong through much of the day. The winds will relax rapidly this evening, but before this Arctic air mass even has a chance to modify, another one will be fast-approaching as we begin the weekend. By late tomorrow, a clipper system and its associated Arctic front will be dropping southeastward across the Great Lakes region right towards the I-95 corridor. Snow will break out in the afternoon hours and continue at night with 2-5 inches likely by early Sunday.

This clipper low pressure system will explode off the Mid-Atlantic coastline late tomorrow and tomorrow night once it passes over the relatively warm waters of the western Atlantic Ocean. This explosive development will lead to a tremendously sharp pressure gradient which will lead to extreme wind gusts around here by late Saturday night and early Sunday on the order of 55 mph or higher. The last thing we need on Sunday - the coldest day of the year so far - is for power outages to develop, but that is definitely on the table for this event so prepare as well as possible. The cold on Sunday will be downright painful and the high winds will cause dangerously low sub-zero wind chill values. This rapidly intensifying storm will produce significant snow once again for New England, and in some ways it will actually be nastier than recent record-setting storms because of the extreme cold and wind that is expected.

Single digits are possible for lows around here on Sunday morning, highs will struggle on Sunday afternoon to even reach the lower teens, and then overnight low temperatures by early Monday morning could drop to right near the 0 degree mark. Another accumulating snow threat will come late Tuesday into Wednesday, but that storm track is still uncertain and it could still end up not being a big problem around here. However, what is certain is that more brutal cold will follow by the middle and latter part of next week - perhaps even on the levels with this Sunday's extreme cold. How about some good news...pitchers and catchers report in just 6 days.

Video

httpv://youtu.be/OQtfYgMWr3I