Several major roads in Downingtown, Chester County, have been shut down, the result of "significant flooding," the borough's mayor reported Tuesday afternoon.

Flooding also was reported in elsewhere in the county, in East Caln Township, and in towns in Ocean County, N.J.

Earlier, after an inch of rain out ahead of a cold front fell upon the Pottstown Airport in 20 minutes, the National Weather Service issued a flood warning for upper Montgomery and northern Chester Counties.

A flood-advisory was in effect for areas just to the north and west of Philadelphia as a line of strong storms from Hatfield to near the Maryland border pressed southeastward.

Much of the rest of the Philadelphia region remains under a flash-flood watch with perhaps two rounds of potent thunderstorms in the afternoon and evening.

The government's Storm Prediction Center sees a "slight risk" of severe storms with winds gusting close to 60 mph.

The rain would be welcome — to an extent; rainfall this month has been about a third of normal.

The flood watch, which runs through this evening, covers Philadelphia, Delaware, Eastern Montgomery and Lower Bucks counties in Southeastern Pennsylvania, and New Jersey, Camden, Gloucester, Mercer and Northwestern Burlington counties in South Jersey.

The forecast calls for showers and thunderstorms, mainly after 3 p.m.

The weather service says some of the storms could be severe, packing damaging winds and heavy rain. The high will be around 88 degrees.

Rainfall amounts of between a half to three-quarters of an inch are possible.

Skies should clear overnight and it will be sunny with a high of about 86 Wednesday.

No other chances of precipitation are in the forecast until Saturday and highs will be in the mid-80s for the remainder of the work week.

Downingtown is experiencing significant flooding.

Police and Public Works have shut down several thoroughfares.

Please remember, our town is at the bottom of a large watershed.

Stay safe and avoid closed roads and sidewalks.