Pottstown Under Tropical Storm Watch

The National Weather Service issued a hurricane watch for Philadelphia and a tropical storm watch is in effect for Chester, Montgomery and Bucks counties.

A watch means that the weather condition is expected, but not imminent.

The local weather forecast calls for tropical storm conditions possible, starting Saturday night with storms and the possibility of heavy rainfall.

The conditions could last through Sunday.

Irene is still a Category 3 hurricane with maximum sustained winds of 115 mph, according to NWS.

The core of the hurricane is expected to move north along the northwestern Bahamas Thursday night.

Irene is getting larger, and the storm watches in the Carolinas have been upgraded to warnings.

The National Oceanic and Atmospheric Administration issued a hurricane warning for the coast of North Carolina from Little River Inlet on the South Carolina border north to the Virginia border.

A hurricane warning means tropical storm force winds are expected somewhere within the warning area within 36 hours.

In the warning area, NOAA forecasts a storm surge of up to 10 feet and life threatening waves.

NOAA issued a tropical storm warning for South Carolina from Edisto Beach north to Little River Inlet on the North Carolina border. A tropical storm warning means tropical storm conditions are expected somewhere within the warning area within 36 hours.

A hurricane watch was issued for the east coast from the N.C. - Va. border north to Sandy Hook, N.J. That includes Chesapeake Bay south of Smith Point.

In the hurricane watch area, NOAA forecasts Irene could produce "significant storm surge flooding."

A tropical storm watch was issued for Chesapeake Bay from Smith Point north, as well as the Tidal Potomac.

The storm is getting larger.

Hurricane-force winds now extend up to 90 miles from its center -- Thursday morning it was 70 miles -- and tropical storm force winds extend up to 290 miles from the center.

NOAA reports Irene produces swells that will cause life threatening surf and rip current conditions along portions of the east coast.