Here is the video forecast, showing why the Middle Atlantic region will have a warmup going into the weekend, but all of the Great Lakes and Northeast will have a cold period after that.
During warmer-than-average weather in winters past, we have frequently taken a look at the upper stratosphere for any signs of a reversal that would signal a change to colder and stormier weather. We saw this winter that such a setup is not at all required to have a cold, stormy period. There has been a strong vortex near the North Pole at the 10 millibar pressure level all winter; 10 millibars is just one percent of the typical pressure down here where we live.
But now, just as many of us look forward to warmer times, a high stratospheric reversal has occurred over just the last 10 days. You can see the difference on this map:
Studies have shown that, in a statistically significant way, such a reversal precedes a high-latitude blocking pattern that forces the jet stream southward. The signal may not be as important in spring as in winter, but if we do get the blocking and southward shift in the jet stream, it would suggest chillier-than-average conditions for the North Central and Northeast states, and perhaps stormier weather. Farther south, an increase in temperature contrast and storminess could mean more severe thunderstorms. As always, it will be interesting to see how all of this plays out.
Looking ahead to <strong>next</strong> weekend, the Mothers Day Weekend, we see quite a difference between the GFS model and European models on where cold Canadian air is heading at 2 a.m. Sunday.
Rain is spreading across the Middle Atlantic states today. Dampness will linger from southern New York state to Virginia tomorrow even as the main rain area moves offshore.
For the rest of the week and this weekend, the upper-air "steering winds" will be arranged in two separate streams. The northern branch will send air from central Canada toward New England.
In the Northeast today, the low pressure area shown on this map will move to the East Coast today, pulling the front south as a cold front. Showers and gusty thunderstorm will affect areas south of the front while steady rain and gray skies are common to the north...
This map shows predicted temperatures for 2 p.m. ET today. This is about two hours before the daily high temperature is often reached. Note how close the chilly and warm air masses are to each other in the Northeast and eastern Canada.
Tomorrow is the anniversary of the birth (in 1564) and death (1616) of William Shakespeare. For this weekend, we expect no Tempest in the Hamlets of the Northeast because no Merchant of Menace will be nearby.