Dominant northern jet to bring down coldest airmass of season late this weekend

Good Thursday morning,

Cold weather patterns continue to exist across the Eastern US including here in western North Carolina. Temperatures have been running below normal since Thanksgiving and that will continue through the end of this week.

Looking at the water vapor, the northern jet is dominant right now as northwest flow at the jet stream level is steering cold air from Canada down into the United States. Abnormally high snow cover across the Midwest has allowed the cold air intrusions to have some staying power. We are feeling one of these today and a much bigger cold air blast will move down this weekend.

Looking at the forecast vorticity on the European Model, another disturbance in Canada is poised to dive southeast down into the Great Lakes Region by Sunday morning. Out ahead of the next cold blast, there will be one good day of temperature moderation here in the Carolinas, we may see some mid-upper 50’s on Saturday but that will be short lived.

The coldest air of the season moves in during the day on Sunday. Strong northwest winds may help produce some brief northwest flow snow showers in the mountains but the big story will be the cold that is being ushered in.

Sunday may turn out to be one of those days where the high temperature is observed around noon (30’s, lower 40’s) with a sharp decline in temperatures by late afternoon and a plummet Sunday night.

By the time you wake up on Monday morning, widespread teens are expected across most of North Carolina with single digits in the High Country. The combination of arctic chill and wind will create a “feels like” temperature in the lower teens across the Piedmont and single digits working into some foothill locations. In the High Country, sub-zero “feels like” temperatures will be observed above 3000 ft.

It will take a couple days to scour out this arctic plunge, high temperatures on Monday will struggle to get out the 30’s and with calm winds, we will have another frigid morning on Tuesday. However by the middle of next week, we begin to see a wholesale pattern change for the country and the strong amplification of the northern jet relaxes and more zonal flow (west-to-east) takes over. Expect us to finally break out of this extended cold pattern that has essentially been in place since Thanksgiving.