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.
This map shows the predicted upper air flow for Saturday. Chilly air from west-central Canada will have a clear path to the Middle and North Atlantic states. However, another warmup seems likely as we go through next week.
A cold front that will cross the Northeast and Middle Atlantic states this afternoon and evening will trigger showers and, in some places, a thunderstorm. Once the front is offshore, a high pressure area from the Midwest will take over for the weekend.
This map shows the high pressure area that is promoting cool, dry weather in the Northeast today. The low pressure area on the left side of the map is associated with a cold front that will send showers eastward tomorrow.
With fine weather likely on most of the days ahead through early next week, leaf viewing will be a cool experience for many, especially in areas highlighted on this map showing the typical progression of peak fall colors:
This map is a forecast of the upper air flow early on Saturday, Oct. 16. It shows a mild to warm pattern for the Great Lakes and Northeast. The second map is for two weeks from today. Northern snow showers, anyone?
...with almost 16 inches of rain in Myrtle Beach, South Carolina, and more than 20 inches around Charleston. You don't find amounts like that anywhere in the historic record for this area. This picture shows the radar-estimated rainfall over South Carolina between Friday afternoon and mid morning today: