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.
When weather systems are relatively weak, small scale variations cause forecast uncertainty because several different weather types (such as showers, sunshine, cloudiness, etc.) can coexist in the same region and change constantly. This map shows such a pattern:
Some of the thunderstorms can become severe, with damaging wind and brief cloudbursts of rain. The greatest chance for locally severe storms should be in the "S" areas highlighted on this map (based on the NWS Storm Prediction Center's guidance).
There is a slight risk for severe thunderstorms later today from north-central Tennessee up across Indiana and Ohio to Michigan and eastern Wisconsin (shown by the "S" area on the map below. Thunderstorms are not predicted for areas near the coast from Delaware to New England.
It is not going to snow any time soon, but in any type of weather the flag is a symbol of freedom. This holiday weekend we celebrate the contributions of those who were there to defend the freedoms we enjoy in these times.
Once again, the rain will miss much of central and northern New England. The region has been in a dry spell, as evidenced by its appearance on this U.S Drought Monitor map.
A cold front crossed the Northeast yesterday. Looking at these maps, which show morning temperatures yesterday versus readings around the same time today, we can see that the biggest drop in temperatures occurred around the lower Great Lakes.