Tuesday 10 a.m.
From Chicago to Syracuse and from Cincinnati to Philadelphia, yesterday was among the very hottest Memorial Days ever. Records were set in Chicago Sunday and again yesterday with highs of 97 and 95. The 97-degree high on Sunday represented the earliest date it had ever been so hot, and came within 1 degree of tying the all-time record for May. In contrast, temperatures may drop to the middle 40s in Chicago tomorrow night. That's still about 10 degrees above record lows, but more than 50 degrees lower than it was during the holiday weekend days.
Temperatures also reached the 90s in Buffalo, Syracuse and New York City. Philadelphia has had its warmest spring ever (where spring means March through May), and it has now been warmer than average for 16 consecutive months, one short of the record (thanks PhillyWeather.net). Meanwhile, cooling breezes from the east held temperatures in the 60s most of yesterday in Portland and Boston. A cool front that was on a line from Lake Erie to Kentucky will take the edge off the heat as it advances. The westerly flow will also bring a reduction in humidity. One exception: the New England coastal area that remained cool will actually have high temperatures tomorrow and Thursday as west winds arrive.
The video shows how things should play out for the rest of the week. Once the heat is broken, it will not return til at least some time next week. Keep in mind that violent thunderstorms are possible ahead of today's cold front... and there may be more nasty storms with the system approaching as we go into the weekend. This map below the video outlines where the greatest chance of severe thunderstorms will be today.
The maps I searched for were from December 1960. I was 13 and was thoroughly overjoyed when Philadelphia got 14.6 inches on Dec. 11 and 12. Schools were closed for three days, something that did not happen again until the Blizzard of January '96.
At midnight, the temperature will be in the 50s to low 60s from Virginia to Southern New England... more like late spring than Christmas time. Meanwhile, cold air will be advancing into western parts of Pennsylvania and New York, driven by strong winds. Earlier, this "cold" air mass looked like it would be more potent than it has turned out to be. This map shows the pressure pattern and some temperatures at 9 a.m.
Temperatures are likely to be in the 50s from Boston to Washington, D.C., during the nighttime hours of Christmas Eve. Dry chillier weather will arrive during Christmas Day, with dry weather lasting until at least Saturday.
This picture, which may or may not have been taken very recently, has a red dot near the North Pole. I cannot confirm that a red dot is there on the ground or that it means anything. We will monitor the area for any signs of activity and advise everyone to maintain the spirit of being nice and not naughty.
Rain with areas of fog should spread from Virginia to New Jersey Monday or Monday night then spread into New England for Tuesday. From the mountains of northeastern Pennsylvania into the interior of New England this could at least start as snow or ice. The GFS for 1 AM New Year's Day looks interesting. See the map below. Whether or not this storm develops and where it will snow or rain cannot be precisely predicted two weeks in advance using these models.
This map is a spaghetti plot showing the upper air currents predicted by members of last night's GFS ensembles. In looking at each line, you see variations, but they all show the idea of major trough centered east of the middle of the country on Christmas Eve.