Vencore Weather
21Nov/14Fri

12:15 PM | *Cold and snow threat for Thanksgiving Eve/Day time period*

Sfc_map_Thurs
[Surface forecast map for Thursday morning by the 12Z GFS-parallel model; map courtesy tropicaltidbits.com]

Discussion

Overview
Yes, a significant warm up is about to take place in the Mid-Atlantic region; however, it will be short-lived and colder air will return to the area by the middle of next week. In addition, there are reasons to believe that a storm may organize near the Mid-Atlantic coastline during the middle-to-latter part of next week at the same time colder air is becoming more and more established in the region.

The warm up
Temperatures will climb into the 50’s on Sunday in the I-95 corridor and then peak on Monday well up in the 60’s with an outside shot at a record-breaking 70 degrees in some isolated spots. A cold front will pass through the region by Tuesday and that frontal passage will begin a downward trend in the overall temperature pattern. High temperatures around here should drop to the 50’s on Tuesday and then the 40’s on Wednesday. Once this cold front moves off the east coast early next week, it’ll tend to stall out in a north-to-south orientation and this boundary zone may then play a pivotal role in the weather pattern later next week.

Cold and snow threat
By the middle of next week, colder air will become better established in the Mid-Atlantic region and abundant moisture will become aligned with the stalled-out frontal boundary zone just off the east coast. One upper-level short wave will ride up the east coast in the Wednesday time frame and then a second wave will follow close behind. It is this second upper-level short-wave (bigger circled area on 500 millibar height forecast map below) that will become the crucial player later next week as it ultimately will help to allow low pressure to ride up along the east coast. Depending on the exact timing of the interaction between this second wave and all that moisture sitting along the coastline, the result could be some snowfall in the I-95 corridor anytime from early Wednesday to later Thursday. Not all computer forecast models are in agreement with this threat and we'll see how things evolve over the next few days. The forecast maps in this posting come from today's 12Z updated GFS computer forecast model (called "GFS-parallel") and the latest 12Z European forecast model also contains a snow threat for later next week. Stay tuned.

500 mb anomalies_Thurs
[500 millibar height forecast map for Thursday morning by the 12Z GFS-parallel model; map courtesy tropicaltidbits.com]

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21Nov/14Fri

7:00 AM | Colder today, but significant (albeit temporary) warm up begins on Sunday and peaks on Monday

6-Day Forecast

Today

Mostly sunny, breezy, colder than yesterday, highs in the mid 30’s

Tonight

Mostly clear, calm, quite cold, lows near 20 degrees

Saturday

Mostly sunny, cold, low-to-mid 40’s

Saturday Night

Mostly cloudy, not as cold as recent nights, low 30’s

Sunday

Mostly cloudy, noticeably milder, periods of rain developing during the afternoon hours and continuing at night, low-to-mid 50’s

Monday

Partly sunny, very mild, an occasional shower possible, but much of the time will be rain-free, upper 60’s

Tuesday

Partly sunny, breezy, cooler, mid-to-upper 50’s

Wednesday

Mostly cloudy, colder, chance for some rain or snow, mid-to-upper 40’s

Discussion

A reinforcing shot of Arctic air moved in overnight and high temperatures this afternoon will be confined to the 30’s and there will be a noticeable wind chill. Winds calm down tonight and Saturday will be a tranquil day with plenty of sunshine, but still on the cold side. A significant warm up begins on Sunday and then peaks on Monday, but it will be accompanied by some more rainfall. The 50's are likely for highs on Sunday, 60's on Monday and perhaps even a flirt with the 70 degree mark and a record-breaker, and then we'll drop back to the 50's for Tuesday. Rain is likely later Sunday and Sunday night along with the warmer conditions and a few lingering showers are possible on Monday; especially, early in the day. Even colder air pushes in by the middle of next week in time for the Thanksgiving Day holiday and we'll have to watch an area of moisture that will likely ride up along the coast at mid-week as it could back in far enough to the west to produce some problems here around Wednesday.

Video

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20Nov/14Thu

7:00 AM | Reinforcing blast of Arctic air arrives tonight; significant warmup on Sunday and Monday to be accompanied by some rainfall and then it turns colder again

6-Day Forecast

Today

Partly sunny, not as harsh as it has been in recent days, breezy this afternoon, highs in the low-to-mid 40’s

Tonight

Mostly clear, quite cold, breezy, lows in the lower 20’s

Friday

Mostly sunny, colder, breezy, mid 30’s

Friday Night

Mostly clear, quite cold, near 20 degrees

Saturday

Mostly sunny, cold, low 40’s

Sunday

Mostly cloudy, noticeably milder, PM rain likely, mid 50’s

Monday

Mostly cloudy, quite mild, occasional showers likely, mid 60’s

Tuesday

Mostly sunny, breezy, colder, low-to-mid 50’s

Discussion

A reinforcing shot of Arctic air will arrive by tonight, but temperatures today will actually modify slightly ahead of this next frontal system. Highs this afternoon should pass the 40 degree mark, but will then be confined to the 30's once again on Friday following the frontal passage. Saturday will remain on the cold side of normal despite plenty of sunshine, but a significant warm up is coming for Sunday and Monday; however, that milder weather will be accompanied by some rainfall and colder air will return later next week.

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19Nov/14Wed

7:00 AM | *Record lows this morning throughout the eastern and southern US; continued very cold this afternoon, but not nearly as windy as yesterday; much milder on Sunday and Monday, but also rainy at times*

record_lows

6-Day Forecast

Today

Mostly sunny today, but there will be an increase in clouds later this afternoon, continued very cold for this time of year, but not nearly as windy as yesterday, highs in the low-to-mid 30’s

Tonight

Becoming mostly cloudy, cold, but not nearly as extreme as last night, lows in the mid-to-upper 20’s

Thursday

Mostly sunny, not as harsh, becoming breezy, low-to-mid 40’s

Thursday Night

Mostly clear, breezy, quite cold, low 20’s

Friday

Mostly sunny, breezy, colder, mid-to-upper 30’s

Saturday

Mostly sunny, cold, low 40’s

Sunday

Mostly cloudy, noticeably milder, PM rain likely, low-to-mid 50’s

Monday

Mostly cloudy, quite mild, occasional showers, low-to-mid 60’s

Discussion

More than 170 records were broken this morning across the eastern and southern part of the country including many in the I-95 corridor region from DC-to-Philly-to-NYC. For example, low temperature records were broken today at the following airports: BWI (19°F), IAD (13°F), JFK (23°F), LGA (23°F) and PHL (20°F-tie). The map above shows the widespread extent of this record-breaking cold in the eastern and southern US with numerous record lows (blue/white circles) and even a few monthly low temperature records (black circles) [map courtesy coolwx.com].

Temperatures today will struggle to pass the freezing mark – way below normal for this time of year - but the wind will be noticeably less intense than yesterday. Temperatures should climb into the 40's on Thursday ahead of a reinforcing shot of Arctic air that will arrive tomorrow night and keep highs confined to the 30's once again on Friday as we close out the work week. Looking ahead, after a cold day to start the weekend, noticeably milder weather is in store in the region on Sunday and Monday, but this warm up will be accompanied by some rainfall.

Video

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