The maximum temperature on Friday will be before dawn. It’s a strange day when the temperature starts to drop when the sun rises and continues to drop until the sun sets. Dangerously cold winds near zero will hit the entire region by Friday evening.
The cold front could also bring a small amount of snow and the possibility of flash freezing as it moves by Friday morning. This can create a dangerous moving area. The front is sure to make the DC area the coldest Christmas holiday since at least 1989.
Showers along the Arctic front will spread across the region from 6 a.m. to noon on Friday. As cold air spills westward, temperatures can plummet and snow can fall.
The big story is how fast the temperature drops. Here’s the timeline:
5am ββto 7am: With the Arctic front moving in from the west, temperatures will rise to nearly 40 degrees. Winds of over 40 mph are blowing during a few showers.
7am to 9am: A cold front cuts through the western part of the region and advances rapidly eastward to the vicinity of the district. When you reach your 30s, the temperature drops sharply. As the front passes, showers can become locally stronger, with a small chance of thunder and light hail. Wind gusts of over 40 miles per hour can damage isolated trees and cause power outages.
9am to 11am: The front passes through the area east of Interstate 95. With temperatures in his mid-20s to near 30s, the lingering rain can briefly turn to snow. At best, it can create dust.
Slippery spots can form on the road if it’s snowing and the temperature is below 32 degrees, or if the pavement has been left wet from previous rains. However, if precipitation stops before temperatures drop below freezing, high winds can dry the pavement, minimizing the threat of flash freezing. The wind chill has gone down in his teens, with gusts of nearly 40 mph.
11am-1pm: Even the snow should be over and the sky should be clearer. By 1pm, temperatures are in his teens to 20s, northwest to southeast range. Gusts are around 35 to 45 miles per hour.
1:00pm to 7:00pm Under mostly sunny skies, temperatures drop to the teens across the region around sunset. Wind chill could be within a few degrees of zero by mid-afternoon before dropping below zero across the region by evening. The wind is still gusting around 35 mph.
This is the strongest signal I’ve seen for WSSI’s Flash Freeze component (which is currently moderately limited for that particular component). There are a few discontinuities due to the temporal resolution of the NDFD data, but they are about the same size and continuous swaths as those generated so far. pic.twitter.com/Wh2tHXqVWI
β Alex Lamers (@AlexJLamers) December 22, 2022
If the trip is mandatory from Friday afternoon to Friday night, be prepared for the possibility of getting caught in extreme cold and high winds. Carry a winter emergency kit. Temperatures are expected to be about 35-40 degrees cooler than they were 24 hours ago, excluding wind chill.
“[I]It will get dangerously cold,” wrote the National Weather Service forecast office, which serves the area. “Even in the subway, I could see the wind cooling down from Friday night to Friday night.”
By Saturday we wake up with wind chills of about zero to minus ten. Wind chills of -40 to -50 degrees can occur in high elevation areas of West Virginia.
The general forecast for Friday through the weekend is for colder weather over the past two days. Forecasts are currently calling for single-digit lows and low-10s lows. These are near-record dates across the region.
Washington’s record low of 5 degrees in 1983 is probably safe, but temperatures below 11 degrees will be as cold as December since 2000.
Saturday’s high temperatures are likely to threaten the record.
Wind speeds will be around 10 to 20 mph, with gusts of around 30 mph through Saturday, and wind chills will remain in the single digits up to nearly 10 degrees.
Conditions are similar, but slightly milder on Christmas morning. Lows are mostly in the late teens to mid teens, with wind chills in the single digits. Christmas highs should hit him in his mid-to-late 20s.
Both days were mostly sunny, and you may have captured the snow falling from outside.