Flash thunderstorms brought high winds, some hail and downed power lines and trees yesterday afternoon, breaking the lazy, hazy calm that had blanketed the area earlier in the day along with a record-breaking temperature of 97 degrees.

The heaviest storm, which hit upper Northwest Washington and southern Montgomery County around 3 p.m., cut off electricity to 4,300 homes, Potomac Electric Power Co. spokesman Tom Welle said. About 1,500 homes remained without electricity as of 12:30 a.m. today, Pepco said.

At the Tournament Players Club at Avenel in Potomac, where grounds were being readied for the Kemper Open, high winds "ripped up 16 tents, including the big pavilion, and ripped off the roof from the CBS broadcast booth," according to Ben Brundred, general chairman of the tournament.

Elsewhere along the East Coast, the story was also heat. In New York, the 95 degree reading broke the record of 92. Windsor Locks, Conn., had a record 97.

The previous record for Washington for May 30 was 95, set in 1895. Yesterday's high also tied the all-time high for the month of May. Humidity that measured at 37 percent added to the discomfort, and the hot, sticky weather is expected to hang around a couple of days, said Calvin Meadows, a National Weather Service spokesman.

Meadows offered a prescription for the coming days: "Stay inside with the air conditioning or head to the pool."

"There's no large mass of cold air moving in to cool things off after these thunderstorms," said Meadows. "We have a lot of moisture left over from precipitation earlier in the week and that caused the thunderstorms."

During the heaviest storms, hail and high winds knocked out power, and some traffic signals in Northwest Washington in the Foxhall Road corridor were also out.

The storms knocked down large tree limbs off Reno Road NW. District police reported that they were busy all afternoon with calls about downed limbs and power outages, mostly in Northwest.

"We're lucky the damage was concentrated in one area," said Welle, who said that some customers who lost power got it back in a couple of hours.

The thunderstorms were caused when the heat that built up because of recent days of clear skies met the moisture left in the air by several rainy days, said Meadows. "The storms might cool things off a little bit, but not enough to even mention," he said.

The storms were violent but spotty. Large parts of the Washington area had little or no storm activity. Prince George's County police, for example, reported no weather-related calls. A Virginia Power spokesman said, "We had a minimal problem. The storm skimmed the northern edge of our area and affected about 150 customers."

If you enjoyed yesterday, chances are you'll love today. Meadows said to expect a high of 90 to 95 and added that there is a 30 percent chance of an afternoon thunderstorm.