Thursday 10 AM
The video discusses our scenario for weather during the Labor Day Weekend. In much of the Northeast, it will be warm and humid with afternoon temperatures reaching the 80s (except perhaps along the Maine coast). The chance for thunderstorms is likely to increase during the course of the weekend, and the most active day may be Monday.
Through mid-morning, today has turned out to be overcast along the I95 corridor from Washington DC to Boston. With a flow from the east and northeast, there is no assurance it breaks today and spotty drizzle and a bit of rain can fall as well. Usually at this time of year, the clouds eventually thin out and allow some sunshine, but timing this is quite challenging.
This pressure analysis shows the flow from the ocean that contributes to the cloudiness. This does not always happen, When there is a fresh dry air mass from Canada that moves offshore and then heads back toward the coast, it can often be bright and sunny. However, when the air is nearly saturated to begin with, it doesn't take much additional moisture to create a solid overcast.
A cold front moving east from the Great Lakes and Ohio Valley will move off the East Coast by tomorrow morning. This map shows the location of the front at 7 a.m. EDT today.
The NWS Storm Prediction Center issued this outlook for today and tomorrow: A preliminary area of showers may advance from the Carolinas as far as southeastern Pennsylvania and southern New Jersey by tonight.
For the almost 24 hours between 10 a.m. ET Tuesday and 9:20 a.m. ET today, here is a the lightning recap. The dry pattern from the Midwest will now advance across New York and New England.
Cooling aloft and heating moist air closer to the ground should trigger strong thunderstorms from eastern New York and much of New England southwest through parts of the Middle Atlantic states.
The front will move into a region with high humidity as it approaches the I95 corridor tomorrow. This is the basis for SPC's forecast of thunderstorms approaching severe limits tomorrow.
Tropical Storm Colin is caught in the southern stream while the northern stream is helping to send unseasonably cool air out of central Canada.