After periods of very abnormally warm weather, surges of very cold air from the Arctic will be barreling out of Canada starting Thursday into next week.
These cold surges are a result of a highly amplified jet stream which has been shifting around North America for the past few weeks with a strong ridge over the Western US and trough over the US. However, the ridge is retreating over the Eastern Pacific and intensifying into Alaska, heating up the Arctic and putting southern Canada and the US in the ice box.
The Storm Prediction Center does have a marginal risk of severe weather ahead of this week’s major frontal system over Southeast TX Friday. The risk appears to be for a isolated severe thunderstorm wind gusts over 60 mph and low risks of tornadoes.
Here in the land of the corn? We should peak in the upper-30s tomorrow morning and then have falling temperatures and increasing winds during the afternoon with freezing drizzle with increasing breezy conditions out of the northwest. Not much snow accumulation expected here, although it could get slick from some of the freezing precipitation. Anyone else in the middle of the country, be careful as the cold air moves in if you’re on the roads!
Quick update on the Thomas Fire in California:
As of this post, the fire burned 272,000 acres…the 2nd largest in California state history (within less than 1500 acres of the state record). It has killed two people, including a firefighter. It is 60% contained. It began December 4th.
No significant rainfall is expected is expected in Southern California through the end of the month based on computer models. The Eastern Pacific ridge of high pressure seems to have a dominant grip on the region unfortunately. A combination of a La Nina pattern and climate change-induced extremely low Arctic sea ice and warm Arctic causing an incredibly amplified jet stream which tends to produce “stuck” and “stale” patterns.
We can only wait and see if the lack of rain and snow forecast in the models in fact verifies for the Southwest US.
Happy first day of (astronomical) winter!
–Meteorologist Nick Humphrey