Before that, the region will see mostly rain, although our colder areas may see a very brief wintry mix from the front end of the storm Thursday morning. Winter weather tips are issued for western Loudoun and Frederick counties and places west of that for the potential of less than 1 inch of snow and light ice coverage.
Rain may be heavy at times, requiring a flood watch by National Weather Service from Thursday morning to Thursday evening.
Thursday’s drenching rain will be followed by a wintry shock. A mega-cold front will blast through the region Friday morning, causing temperatures to plummet near 40 by evening. This foray into the Arctic will produce the region’s coldest December since at least 2004 and the coldest Christmas since 1989.
Here’s what to expect over the weekend:
- It’s a long-lasting event, including heavy rain on Thursday, followed by a quick drop in temperatures on Friday and cool weather over the weekend.
- Slippery patches are possible on Thursday morning, mainly west and north of the city.
- Rain will fall for most of Thursday and will be heavy at times from midday into the evening.
- A big cold front will move through Friday morning, sending temperatures back down from 35 to 40 degrees in 24 hours and likely bringing snow showers and freezing temperatures.
- It will be the coldest two-day Christmas holiday since 1989, with wind chills near zero on Christmas Eve morning.
The bulk of Thursday’s precipitation will be rain. Rainfall totals of about 1.5 inches should be common in the D.C. area, with some locations nearing 2 inches.
4am to 7am Thursday: Precipitation should begin to arrive from the west, moving into areas mainly west of Interstate 95. A very light icing is possible, mainly in elevated areas far west and north of the Beltway, possibly following a blanket of snow.
7am to 1pm Thursday: Rain should also cover the rest of the area, with some freezing rain in the west. It could take until late morning to reach temperatures above 32 degrees west of Route 15 (from Warrenton to Leesburg to Frederick). Temperatures are expected to rise into the 30s elsewhere, with the coverage and intensity of the rain increasing by the early afternoon.
13:00 to 19:00 Thursday: Frequent periods of rain should continue, heavy at times. There may be a rumble of thunder. Temperatures are expected to rise to near 40 degrees in our cooler areas of the northwest to the mid-50s in the south and southeast. Strong winds with 40 mph gusts are possible.
7pm Thursday to 7am Friday: Rain is expected late in the evening and the wind should ease slightly. Much of the night may be dry, but precipitation is an increasing risk towards dawn. Temperatures should remain mild overnight before cooling into the low 40s by sunrise.
We’ll likely wake up to temperatures near 40 degrees on Friday, and that could be as high as they get for a while. Between about 7am and 10am, an arctic front will pass with increasing winds and a sharp drop in temperatures.
“The onset of strong winds with the arrival of a front can be quite sudden and dramatic,” said Jeff Halverson, severe weather expert with the Capital Weather Gang. “With the ground very wet from the rain, isolated downed trees and spotty power outages are possible.”
A little snow or mixed rain may fall during the trek. Any remaining wet spots on paved surfaces can freeze.
“Weather models are advertising the potential for snowfall behind the front,” said Wes Junker, CWG’s winter weather expert. “Even without snow, puddles on the roads are likely to freeze over, so there could be slick spots.”
If there is snow as the front passes, the chance of icy roads increases, Juncker said. If the front moves through without precipitation, strong winds can help dry pavement before it has a chance to freeze.
By early afternoon, wind chills should drop to the single digits and teens in most areas with wind gusts between 40 and 50 mph. Temperatures will quickly drop into the low 20s during the afternoon hours.
Gusts should ease by the evening, but still gust around 25 mph to 35 mph by Friday night, bringing wind chills near freezing. In the mountains to the west, wind chills of minus teens to minus 30 degrees are likely.
If you must travel on Friday, consider bringing emergency supplies such as blankets, food and water in case of a delay.
A frosty Christmas weekend
With clear skies, Christmas Eve morning lows are expected to range from around 10 to 15 degrees (perhaps a bit warmer in the centre). Expect afternoon highs of only 20 to 25 degrees with wind chills no higher than the teens.
On Christmas Day, lows will range from the single digits to the mid-teens. Afternoon highs may be milder than Saturday’s, but still only reach the mid to upper 20s.
It is almost certain to be the coldest two-day Christmas holiday since 1989. This year the high was 23 with a low of 10 on Christmas Eve and the high was 29 with a low of 11 on Christmas Day. Several cold records may fall in the region.
If the low temperature drops to at least 16 degrees on Saturday or Sunday, it will match the coldest of 2022.
If it drops to 15 degrees or colder, it will be the coldest January since 2019. Since 2000, only three December days have seen temperatures of 15 degrees or colder, most recently in 2004.
Jason Samenow and Dan Stillman contributed to this report.
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