Friday 8 a.m.
AccuWeather celebrated its 50th birthday yesterday. Several hundred people gathered to hear short talks by some of the company's leaders as well as two elected officials from Congress. It had rained earlier in the day, with storms bringing vivid lightning, booming thunder and gutter-gushing rivulets of rain. However, by the time the festivities began, some drier air had arrived. Later, we were treated to a nice rainbow just above the roof of the building.
Cooler air has now replaced this week's hot spell all the way from the Great Lakes to the East Coast. There is still some rain, especially in eastern New England and downwind from lakes Erie and Ontario, but dry weather will be the rule there this weekend. This video has more.
As cool air crosses the relatively warm Great Lakes, the low-level air warms, and this reduces the barometric pressure. This morning, that effect showed up as weak troughs embedded in the cool surface flow moving southward from eastern Canada.
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:
A major snowstorm will affect the area from Iowa to Michigan tonight and tomorrow. At first, snow can melt on streets, but as it continues and the temperature drops, the area impacted by slippery conditions will increase dramatically. This map shows expected accumulations:
This map shows two cold fronts in the northeast quarter of the nation; 9 a.m. ET temperature are plotted. The isobars are closest together over the central and western Great Lakes, and this is where the strongest winds were occurring.
This map shows how large an area is directly affected by precipitation on Tuesday morning. The low pressure center was in Kansas early today but will move all the way to Hudson Bay by Thursday while sending a cold front eastward on its south side.