Monday 9:45 AM
A storm crossing the Gulf states dropped heavy rain over a wide area, and the moisture is moving northeastward. However, the upper air trough supporting the rain is shown to weaken slowly on the computer model (I use this term interchangeably with numerical forecasts) maps, and so places in the Northeast should not match the Gulf states in the rainfall amount department. One thing that is apparent is with a persistent flow from the Gulf states to New England, it will be warmer than average for this time of year.
Last week at this time, I showed a GFS forecast map for Oct. 10 that suggested it could snow in central and northern Pennsylvania. I suggested the model would change looks over time and, in fact, the very next run has a warmer look and no snow. On the other hand, a typhoon re-curved over the western Pacific, and this kind of event has often been followed by an upper air trough n the East about 10 days later. The most recent runs of GFS has trended toward this trough in the East scenario, and this suggests next week will be quite a bit cooler than this week (with the first push of cooler air arriving this weekend).
The numerical forecasts (I use this term interchangeably with computer models) for next week will certainly change in various ways before next week arrives, but there are hints that the higher terrain downwind from the Great Lakes could get their first snow showers of the season next week. This map for next Thursday shows a close call setup for this:
Meanwhile, my daily video shows what we can expect this week:
One concern: the chance of cold frontal snow squalls that could move all the way to the East Coast tomorrow night. Sudden snow squalls have been implicated in chain reaction collisions that turn deadly and damaging.
These two maps show the change from the very, very cold flow likely this Saturday to the much milder Pacific-origin westerly flow later next week.
When we look more closely, we see a variety of disturbances embedded in the main current, each capable of temporarily increasing or cutting off the chance of snow. This map shows the setup:
This map shows the circulation around the offshore storm and a larger but less intense storm moving into the Great Lakes. With this sprawling storm likely to be in the region for several days, the weather can vary widely.
...speculation about a snowstorm Monday or Tuesday, and one is still possible. However, timing and placement remain elusive. This map shows the GFS ensemble mean "solution" for Tuesday morning showing snow just off the New England coast. Watch this story evolve on accuweather.com all weekend.