Isaias In PA: 6 Inches Of Rain Possible 'In Short Period Of Time'

PENNSYLVANIA — A tropical storm warning has been issued for the Philadelphia region as Tropical Storm Isaias turned away from the Florida coast and moved north on Monday morning.

Heavy rain is expected with the potential for flash floods all across region as Isaias continues the north-northeast trek, the National Weather Service's Mount Holly office said Monday morning.

Forecasters say Philadelphia and its suburbs can expect as much as 6 inches of rain in a "short period of time."

There is the potential for a major flooding rain and evacuations and rescues are likely, the weather service said.

Tropical storm-force winds and some rain likely will arrive by daybreak on Tuesday. Expect winds of 40 to 50 mph with gusts to 70 mph from Tuesday morning until Tuesday afternoon.

Isolated tornadoes are possible as well, the weather service said.

Isaias was expected to regain hurricane status later Monday as it moved north toward the Carolinas, where it was expected to make landfall. The National Hurricane Center's 8 a.m. briefing said Isaias had picked up speed, moving north-northeast at 13 mph, and had maximum sustained winds of 70 p.m.

The primary concern, forecasters said, is the expected heavy rain. Between 4 and 6 inches of rain is expected to fall in Eastern Pennsylvania, from the Poconos to the Delaware border. Some river flooding is possible, although forecasters said the main stem of the Delaware River is not expected to flood.

There is a potential for coastal flooding from a 1- to 3-foot storm surge, though forecasters said the highest potential for that is in the Chesapeake Bay area. Low-lying areas that flood regularly with heavy rainstorms or extreme high tides likely will be flooded as a result of Isaias.

"Rivers and tributaries may rapidly overflow their banks in multiple places. Small streams, creeks, canals, arroyos, and ditches may become dangerous rivers. In mountain areas, destructive runoff may run quickly down valleys while increasing susceptibility to rockslides and mudslides," the National Weather Service said. Flood control systems and barriers may become stressed.

Here are the areas with at highest risk of flooding:

With reporting by Karen Wall