Tuesday 9 a.m.
Yes, the GFS operational run from yesterday afternoon included a forecast map for the afternoon of Oct. 10 that suggested heavy wet snow would be falling over the higher elevations of central and northern Pennsylvania. That map is below. The output from the same model run 12 hours later shows no such thing... just a Great Lakes low pressure area causing showers with fairly mild temperatures. That map is below the snowy version.
At this point, we cannot put much faith in either idea.
In the shorter range, southwest winds are sponsoring a warmup in the Northeast from today into tomorrow. A cold front will then move though to cause some showers and in places a thunderstorm... followed by cooler air. The front will stall in Virginia or Norrth Carolina, and a low pressure area forming along the front can then bring rain to the Middle Atlantic states on Friday. The video has more.
It appears that a large low pressure area will form in the Plains this weekend and then drift very slowly eastward next week. This could lead to a lot of rain over a large area. This map depicts the Euro model predicted rainfall between now at midday Saturday May 3rd.
Thunderstorms broke out in eastern New England this morning. Here is a lightning map showing strikes between 8 a.m. and 10:30 ET:
I'd like to think that my explanations of what was going on enlightened him, but we all know better! This map shows the distribution of lightning from around daybreak yesterday to the wee hours of the morning today.
Omega blocks are known for causing long periods of whatever kind of weather you had when the block was getting established. In other words, if it was rainy, you were in for more (perhaps a lot).
This satellite picture shows the storm that affected the Southeast on Saturday (1) , the frontal system that will reach the East Coast late tomorrow night (2) and a disturbance in the Pacific Northwest that may affect the Northeast at the end of the week (3) .
A deck of clouds about a half-mile overhead spread westward from the Atlantic to much of the I95 corridor from DC to Boston early this morning. These cloud decks can be a forecaster's nightmare in the spring because ...