A foretaste of winter to start the working week


Analysis of high-altitude winds shows that a large-amplitude wave has established itself in the jet stream over central and eastern North America, sending air from the Canadian Arctic directly to the Midwest. This has resulted in our temperatures being almost 10 degrees below normal over the weekend. Conditions will get worse before they get better. Satellite imagery identified a core of fast-moving air in the jet stream over northern Canada late Saturday. As this feature dips south on Sunday and Monday, it will serve to deepen a pool of unusually cold air over the western Great Lakes. This arrangement can produce patchy snow showers as far north as Illinois on Monday. Snow showers, intermittently mixed with rain, are likely over parts of NW Indiana and SW Michigan. High temperatures on Monday afternoon are expected to be around 20 degrees below normal. The late November chill is compounded by NW winds gusting in excess of 40 mph. Although these conditions are expected to improve by mid-week, sub-normal temperatures will continue through Thursday before any significant warming begins.
Winds howl when temperatures change
Chicago is said to be truly a “windy city” in the coming days. Rapid changes in temperature are usually associated with increased wind speeds. Zones of rapid temperature flow produce air pressure changes, which in turn increase wind speed. Therefore, average wind speeds are higher during the transitional periods than in summer, when the hemisphere is more evenly warm.


https://wgntv.com/weather/weather-blog/a-taste-of-winter-to-start-the-work-week/ A foretaste of winter to start the working week