Wednesday 9:30 a.m.
Snow will fall from parts of Kansas to the upper Great Lakes. Cool, rainy weather will be common east and southeast of the snow area. Record heat is expanding in the Southwest, and normally moderate San Diego could have temperatures well up in the 90s on Friday. Chicago will have midsummer temperatures this afternoon, but much cooler air is likely to be in control starting tomorrow. There will be some rain once the cooler air arrives, but whether it falls in patches on and off or instead turns into a concentrated flood producing rain band remains to be seen.
In the Northeast, a high pressure area now in control will be reinforced by another high from northeastern Canada. As that second high arrives, cooler air will spread into New England then the Middle Atlantic tomorrow night and Friday. It should turn warmer again during the weekend.
In the "what could go wrong?" department, another batch of cloudiness has appeared east of New England and has been spreading southwestward toward the New Jersey coast this morning. The picture shows the clouds. Our forecast is based on those clouds not coming ashore to affect areas from Philadelphia northward. We'll be watching.
Today's Northeast Video
This video focuses on Chicago:
Later this week we expect to see a split flow pattern aloft. One branch of the flow will come in from the Pacific and go across the Northern states. With no access to arctic air, this setup favors milder-than-average conditions for the North Central and Northeastern states.
Wet weather is coming toward the Northeast, and episodes of rain may be spread out over a two- to three-day period. Supporting this idea is this satellite/radar image from mid-morning Monday showing pockets and bands of rain affecting several areas.
On this map from 10 a.m. ET Thanksgiving Day, you can see the high pressure area that is causing dry and mild weather in the East and the cold front farther west.
During the late afternoon and early evening hours, the cold front of a knife will slice through the turkey and cause it to accumulate 1-2 inches on plates...
This satellite picture shows clouds over parts New York and Pennsylvania, as well as areas of low clouds, fog and snow cover from Michigan to Illinois. Most of the Northeast should have at least some sunshine through Thanksgiving Day.
As we go through the week, the flow aloft over the East will become southwesterly. This will promote a major warmup. This map shows the projected upper-air flow for Thanksgiving afternoon: