Thunder and lightning roll through area, but rain will stay awhile

Our wetter-than-average August featured a sky show Monday afternoon as thunder and lightning punctuated what had been an otherwise gray, rainy day across the Puget Sound.

Lightning was especially heavy in the Kitsap County area but was also reported across King and Snohomish counties, said Johnny Burg, meteorologist for the National Weather Center in Seattle.

The storm was expected to taper off by today, but more showers and cooler temperatures were expected to return by tonight.

Reports of funnel clouds Monday on Lake Washington were confirmed by the National Weather Service after meteorologists saw video footage from television stations.

They described the clouds as "cold-air funnels" — a much weaker version of the menacing twisters characteristic of Midwest thunderstorms.

"I suppose (the cold-air funnels) might knock over a garbage can if it touched down," said meteorologist Mike McFarland. "They don't do much."

Meanwhile, rainfall so far this month has been a full inch above normal for the entire month.

The average August rainfall at Seattle-Tacoma International Airport is 1.7 inches, according to the Weather Service. By Monday evening, it had already reached 2.71 inches.

"We've had some record days of rainfall," said Jay Albrecht, a weather-service meteorologist.

With this week's weather, "it's possible we could get close to the 3-inch mark," he added.

Drier days are expected by the weekend. By Thursday, skies should be partly sunny with high temperatures in the low 70s — a trend that's expected to continue through Sunday.

A series of low-pressure systems moving through the area is bringing the rain and cooler temperatures.

That is consistent with this summer's weather pattern, which has alternated regularly between hot and cool days, Albrecht said.

The heat wave Aug. 13 to 15 pushed average temperatures up for the month, making it 1.5 degrees above normal for August, he said. But the numbers will average out with the cooler weather in the days to come.

That means another heat wave is unlikely.

"We could stay on the chilly side for the next couple of weeks, as we get into September," he said.

Seattle Times staff reporter Jim Brunner contributed to this report

Sonia Krishnan: 206-515-5546 or skrishnan@seattletimes.com