2:20 PM | **Colder pattern returns to the Mid-Atlantic region on Christmas Eve (Sunday)…threat for rain changing to snow in parts of the area**
Paul Dorian
12Z GEFS forecast map of 850 mb temperature anomalies averaged over 5-day periods (days 1-5 left; days 6-10 right) with a big change to colder-than-normal in the Mid-Atlantic region; maps courtesy tropicaltidbits.com, NOAA/EMC
Overview
After a mild and wet day on Saturday, a strong cold front will pass through the region and usher in a colder air mass for Christmas Eve (Sunday) and Christmas Day (Monday). In fact, it looks like once this colder pattern sets up in the Mid-Atlantic region, it’ll stick around for the next couple of weeks. Low pressure is likely to form near the coast late this weekend as the colder air filters into the I-95 corridor and this could generate more rain which could change to snow before ending; especially, in the northern Mid-Atlantic and Northeast US. Looking ahead and still in the "speculation" phase, there may be a nice setup at the end of next week for snow in the region.
Low pressure along the Northeast US coastline as of Monday morning according to the 12Z Euro; map courtesy WSI
Details
A strong cold front will approach the region on Saturday and temperatures will turn quite mild ahead of it with highs well up in the 50’s in most spots. Rain is also likely ahead of the frontal system from Friday night into Saturday. Colder air will filter into the I-95 corridor on Sunday following the passage of the cold front and it looks like it may stay generally colder-than-normal during the next couple of weeks.
500 mb forecast maps for Monday morning by the Euro model (left) and GFS model (right) with differences in the handling of the upper-level wave of energy; maps courtesy WSI, NOAA/EMC
Low pressure will try to form near the east coast late Sunday as the colder air pushes into the Mid-Atlantic region and this could generate more rain for the DC-to-Philly-to-NYC corridor. There is a chance that it gets cold enough for a changeover to snow before precipitation ends; especially, north of the PA/MD border. There are some differences in the GFS and Euro computer forecast models for this late weekend system with the Euro model generating a stronger storm and a better chance for a changeover to snow in the northern Mid-Atlantic/Northeast US. The difference in the model solutions is in the handling of the upper-level wave of energy which is “strung out” in the GFS and stronger in the Euro (circled regions).
Later next week, strong high pressure is likely to shift eastward across the northern US and this could result in a favorable pattern for snow around here at the end of next week. With strong high pressure potentially anchored to our north and northwest, there looks like there may be lots of moisture heading our way from the south-central states and this could result in snow at the end of next week – still a lot of time to go until then, but the potential setup is favorable for snow.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com
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