A sudden onslaught of rain closed roads and stranded cars in parts of Montgomery and Bucks Counties yesterday, surprising even veteran weather-watchers with its fury at one point.

Police and fire officials were busy in Whitemarsh Township and Upper Dublin in the Fort Washington area, setting up barriers and rescuing at least one motorist who tried to plow through the water.

The Holiday Inn in Fort Washington was evacuated as a precaution until 6 p.m., said Sara J. Erlbaum, chair of the Board of Supervisors in Whitemarsh Township, which has more than its share of flood-prone creeks.

"There's a reason it's called Whitemarsh," Erlbaum said. "It floods here. That's the reality of it."

The heaviest rain fell in Montgomery and Bucks Counties, with some places getting more than 5 inches over a couple of hours, said Anthony Gigi, a meteorologist at the National Weather Service office in Mount Holly. During the worst of it, an inch of rain fell in just 10 minutes, according to preliminary reports.

"That's Cherrapunjee territory," Gigi said, referring to the place in India that is often called the world's rainiest.

In Hatboro, cars were flooded in the parking lot of the Robert Bruce East apartments on Horsham Road. Fire officials considered evacuating some of the apartments but decided not to after the water retreated.

"Another three feet, it would've been in the first floor of several of these buildings here," resident Kerry Palanjian said.

In Whitemarsh, parts of Stenton and Pennsylvania Avenues were closed, as was Morris Road, Erlbaum said.

She said the township was already undertaking a number of projects to combat excess storm-water runoff, including improvements in retention basins and roadway inlets.