Blockbuster storm, harsh arctic outbreak set to hit U.S. by Christmas
The Washington area will be most significantly affected by this extreme weather pattern after the back-end cold front of the Great Lakes storm passes Friday. Temperatures will plummet below freezing, with howling winds and we can’t rule out snow showers or light snow. Washingtonians will experience the coldest air so far this season.
There could be a bit of a winter mix early Thursday
We could see some chilly precipitation in the area as the storm system moves into the area on Thursday, provided it gets early enough in the day. Even if that happens, any sleet, snow or freezing rain is likely to be short-lived and concentrated west of the Interstate 95 corridor.
With precipitation coming and temperatures mostly above freezing, the winter weather potential of this system at the front appears to be more threatening than last Friday’s storm, which produced mostly rain in the region (except for the west-northwest some freezing rain).
The milder temperatures were largely the result of high pressure sliding off the northeast coast ahead of the storm, which helped create warm wind currents over the ocean. The center of the storm is also expected to be stronger compared to last week, which should help provide ample and relatively warm southerly winds ahead of an arctic front arriving late Friday.
The Baltimore/Washington Weather Service office said there was a slight risk of cold weather for western counties in our region Thursday and Friday, but no risk for nearby areas. Anything that seriously disrupts winter weather should be restricted to our western mountains.
After about 2 inches of rain late last week, another inch or two appears to be on the way later this week.
The heaviest rain is most likely to occur between late Thursday and Friday morning. There could even be thunder on Thursday night or Friday, given the warmth and humidity surging northward ahead of Friday’s cold front.
Here are the precipitation amounts shown by some recent model runs, including the extent of DC and the local area in parentheses.
- European ECMWF – 0.9 inches (0.75-1.5 inches)
- US GFS – 0.9 inches (0.75 to 1.5 inches)
- Canadian GEM – 1.2 inches (1 to 1.5 inches)
Washington sees 2.41 inches of rain in December and averages 3.41 inches for the month. The next storm will bring the city closer to above normal precipitation this December.
How much will the temperature drop and when?
Friday will be an unusually hot day for the region. Morning readings east of the Blue Ridge soaring into the mid-50s to mid-60s seems like a good bet as the center of the storm circles across the Great Lakes and a powerful cold front approaches the region.
Current weather models suggest that the front will pass over Washington at noon, and temperatures will drop rapidly thereafter. Numbers could dip below freezing in the western parts of the region in the afternoon, before Washington, D.C., and east around sunset.
As cold air rushes into the region, it cools quickly enough that any precipitation left behind by the front turns to snow. There may not be much precipitation at this time, but there may be light snow blowing, snow showers or brief blizzards. Under the right conditions, a coating or something similar may settle on the spot.
The wind chill in the region was at least as cold as the local single digits through Friday night, with sub-zero wind chill in northern Maryland and elevated elevations in our west.
As the cold front moves through Friday, brief gusts of wind speeds near 50 mph are possible, which could cause downed trees and wet ground, causing power outages. Wind gusts of 30 to 40 mph could continue into the evening. Winds could dip into the 20s by late Friday night.
With wind gusts of 20 to 30 mph on Christmas Eve and Christmas Day, the wind chill is likely to persist throughout the weekend. Single digits will persist on Saturday, with teens more likely on Sunday.
Coldest Christmas Eve and Christmas in decades
On Christmas Eve morning, low temperatures will reach 15 to 20 degrees without rising too much during the day. The afternoon highs in the mid-20s to nearly $30 currently look like a good target.
Christmas morning will be even colder, with lows in the 10s and 20s. Afternoon temperatures may be slightly cooler than Saturday, but the region should remain at or below 32 degrees for a second day in a row, with highs in the high 20s and low 30s.
The city’s average high on Christmas Eve and Christmas is 47 degrees and a low of 33 degrees.
The last time both were in their 30s was 2004. To find the last time temperatures didn’t rise above freezing on any single day, we looked back to 1999. Right now, 2022 looks to be the coldest two-day holiday season since 1989, with Christmas Eve peaking at 23 degrees and Christmas Day at 29 degrees.