The National Weather Service is calling for 2 to 4 inches throughout the region, with perhaps 6 in some places, said Jim Hayes, a forecaster in the Mount Holly office.
"We're taking our normal precautions," said Robert Adams, police chief in West Norriton Township, along the Schuylkill in Montgomery County. It is one of the region's most flood-prone communities, with more than $7.5 billion in federal flood-insurance losses since 1978.
He added that if the worst did occur, the emergency response would not be compromised by drought-induced rustiness.
"Unfortunately, we've done it too many time to really get out of practice," Adams said.
The storm center may pass quite close to Philadelphia, and tree-threatening tropical-storm force gusts from the southeast of 39 m.p.h. or stronger are possible, Bastardi said.
For Philadelphia, it would be a nameless storm, although a dissipating Nicole, a blob of Caribbean moisture that was named Wednesday after its winds reached 40 m.p.h., is donating its generous moisture.
Hayes said Nicole's impressive atmospheric juice would be picked up by a storm forming early Thursday along a frontal boundary along the Carolina coast. The exact track of this storm as it moves north is not certain, and that would determine where the heaviest rains fall.
The rain is expected to come in two batches, with perhaps a break before a second pulse arrives later Thursday.
Fortunately, most of the region's streams that are monitored by the U.S. Geological Survey are at near- or below-normal levels as rainfall amounts have been about half the average for the last 60 days through most of the region - a third in the case of Philadelphia.
If the forecast is correct, Philadelphia could see as much rain from the storm as it has received in the last two months.
Contact staff writer Anthony R. Wood at 610-313-8210 or twood@phillynews.com.
