Blockbuster storm, bitter arctic outbreak to destroy US before Christmas
The DC area will see the most significant effects of this extreme weather pattern after the cold front passes on the back of the Great Lakes storm on Friday. Temperatures will drop below freezing and the wind will roar, and we can’t rule out some snow showers or gusts of wind. Washingtonians will experience the coldest air of the season yet.
A bit of winter mix possible early Thursday
We could see a bit of winter precipitation in the region just as the storm system moves into the area on Thursday, provided it’s early enough in the day. Even if that happens, any sleet, snow, or freezing rain would likely be brief and concentrated west of the Interstate 95 corridor.
With temperatures mostly above freezing when precipitation falls, the winter weather potential of this front end system looks even less threatening than last Friday’s storm, which brought mostly rain to the area (aside from some freezing rain in the far west and northwest ).
The milder temperatures are mainly due to high pressure slipping off the northeast coast before the storm arrives, helping to set up a warmer wind stream from the ocean. The storm center is also expected to be more powerful compared to last week’s, which should help provide abundant and relatively warm southerly winds for the Arctic front that won’t arrive until late Friday.
The Baltimore/Washington Weather Service office has western counties of our area with a small risk of winter weather on Thursday and Friday, but no risk in the immediate area. Anything that stands in the way of significantly disruptive winter weather should be confined to mountainous areas west of us.
After collecting about 2 inches of rain at the end of last week, another inch or two of rain seems to be ready at the end of this week.
The heaviest rain is likely to fall between late Thursday and Friday morning. There may even be a thunderstorm on Thursday night or Friday, given the heat and humidity moving north ahead of Friday’s cold front.
Here’s what some recent model runs show for precipitation, both in DC and the range for the local area in parentheses.
- European ECMWF – 0.9 in (0.75-1.5 in)
- US GFS – 0.9 in (0.75 to 1.5 in)
- Canadian GEM – 1.2 in (1 to 1.5 in)
Washington has seen 2.41 inches of rain in December, compared to 3.41 inches as an average for the entire month. The next storm should push the city near and above normal for precipitation in December.
How much temperatures will drop and when
Friday promises to be a wild day for temperatures locally. Readings as high as the mid-50s to around the 60s seem like a good bet east of the Blue Ridge in the morning as the storm center swirls through the Great Lakes and a strong cold front approaches the region.
Current weather models suggest that the front will pass through Washington in the afternoon and temperatures will immediately drop rapidly in its wake. In the western parts of the area, numbers may drop to and below freezing during the afternoon, then into DC and by sunset or so in the east.
As cold air flows into the area, it cools quickly enough to turn any precipitation behind the front into snow. There probably won’t be much fall at this point, but some gusts of wind, snow squalls, or a brief blizzard may blow by. Under the right conditions, a coating or so can fall off in spots.
By Friday evening, the region is looking at wind chills as cold as the single-digit local and below zero in northern Maryland, as well as elevation to the west.
Wind gusts may briefly approach 50 mph as the cold front moves through Friday, which could lead to downed trees and power outages given the wet ground. In the evening gusts of 30 to 40 mph can be normal. Winds are likely to decrease to above 20 later Friday evening.
Given wind gusts of 20 to 30 mph on Christmas Eve and Christmas Day, chills are likely to remain brutal all weekend. Single numbers persist on Saturday, with teens more likely on Sunday.
Coldest Christmas Eve and Christmas Day in decades
On the morning of Christmas Eve, low temperatures will reach the mid-teens to below 20 without rising much during the day. Mid-20s to near-30s midday highs seem like a good target for now.
It’s going to be an even colder Christmas morning, with lows ranging from about 10 to 20. Afternoon readings may be slightly less frozen than Saturday, but the area should stay at or below 32 for a second straight day, with peaks in the upper 20s and low 30’s.
Average temperatures for both Christmas Eve and Christmas Day are 47 for a high and 33 for a city low.
The last time both were in the 30s was in 2004. To find the last time the temperature did not rise above freezing on either day, let’s look back to 1999. Right now, 2022 looks like the coldest for the two-day holiday since 1989, when peaks reached 23 on Christmas Eve and 29 on Christmas Day.