Wednesday 10 a.m.
Dense fog has been ruining travel plans in parts of the Midwest this morning, with hours-long delays and many cancellations of flights to and through Chicago. At this time of year, there is much less solar energy available to help evaporate the fog and lift ground-level temperatures above the saturation point. The National Weather Service issued dense fog advisories that run right to lunchtime.
In the Northeast, it is a fine day, and Thanksgiving Day will feature sunshine (although the day may start foggy). Temperatures tomorrow will climb into the 50s across New England and even higher farther south.
A cold front that crosses the Great Lakes Friday will speed well off the East coast Saturday. The cold flow behind the front will set up snow flurries and heavier squalls downwind from the Great Lakes in the Appalachians, and it would not be surprising to see some flakes in the I95 corridor for a short time.
Looking ahead to next week, cold air will be widespread across Canada. However, separate upper air current will run from the Pacific eastward across the United States. Passing storms will tap into cold air as they move past each place, but mild air flowing northward ahead of the storms seems likely to prevent any major snowfalls in the Middle Atlantic States anytime soon.
This video has more.
Note: egrets are beautiful birds.
This table shows the ensemble means for the next two weeks at Philadelphia: It suggests that whereas it does turn cold, any snowfall looks quite limited.
It is too early to be confident about any forecast for Christmas Day (or even the week before). However, the GFS model does go out 16 days, and it has a cold look for the Northeast exactly one week before Christmas.
As the flow aloft becomes southwesterly, mild moist air will spread northeastward from the Gulf States. In summer, this creates a hazy, very warm and humid scene for the Northeast. Now though, the warmth is slowly drained away as the moist mild air advances over cold ground. With temperatures near the saturation point, clouds form.
If each one of us lights an inner flame for just one thing- just one aspect of our lives we are thankful for, the warmth we create can light the world on Thanksgiving. The flame of warmth and love can burn so bright that no cold wind on earth can blow it out.
One concern for later this afternoon and evening is a trailing batch of precipitation moving northeast from the Carolinas. If this survives to reach the I-95 corridor just as the cold air arrives, there could be a brief but nasty episode of snow that makes it slippery.
The exact placement of the storm center will determine who gets into the real warm air coming up on the east side of the storm and who stays in the chilly air on the west side.