Friday 7 AM
With a high pressure area building and drifting slowly southwestward from Maine, sunny weather will dominate the weekend in the entire Northeast. It is a little unnerving to the forecaster to see such a vast area of winds coming from ocean to land and not predicting overcast weather. However, at least from Delaware northward, the flow is not over the ocean terribly long before coming ashore, and its origin is in eastern Canada, where it is very dry.
Outside AccuWeather headquarters, a fine spring sunrise, the sunlight filtering through trees with budding leaves and flowers. This weather will be common in the Northeast all weekend.
This map shows the surface pressure pattern across the Northeast at 7AM EDT:
With a high pressure area over Maine, a low pressure area over western Indiana and an upper-air storm spinning over the western Great Lakes, the stage is set for wet weather in the Middle and North Atlantic states.
This map is a rainfall forecast from the NWS Middle Atlantic River Forecast Center located in State College, PA.
The upper-air flow forecast for this evening shows the trough that helps to support rainfall ahead of the cold front.
After reaching the 80s today from NYC to Boston, it might not be that warm again through much of next week.
A noticeable push of cooler air will spread southward from Ontario and Quebec into the eastern Great Lakes and New England between tomorrow and Saturday.
A cold front from eastern Canada will slide southward along the East coast between late Friday and the end of the weekend. For the area from Philadelphia to Boston, where temperatures will reach the summery 80s each day through Friday, it will mean a noticeable change to cooler weather.