Heat wave? More like a heat trickle as temperatures to fall by Sunday

Normally, when the thermometer starts to tick upward in the early days of May, Bay Area residents can prepare to settle in for a long stretch of heat.

That won’t be the case this time, according to the National Weather Service.

Shorts, T-shirts and air conditioners all figure to be utilized Thursday, Friday and Saturday throughout the region, but meteorologist Roger Goss said there’s a blast of cooler air on its way and perhaps even some rain after that.

“It’s a bit unusual to see a pattern like this around this time,” he said. “But that’s what we have.”

Temperatures throughout Santa Clara, Alameda and Contra Costa counties all will be in the upper 80s, and some in far interior locations — Livermore, Concord and Brentwood in the East Bay; Morgan Hill and Gilroy in the South Bay— will see the gauge climb into the mid-90s by Saturday.

By Sunday, an off-shore flow from the Pacific Ocean will begin to replace the high-pressure ridge that has allowed temperatures to climb, and Bay Area residents will feel temperatures that are “probably 15 degrees cooler,” Goss said.

“Even inland, you’re going to see temperatures fall into the lower 80s,” he said. “Then they may fall again, and we may see rain.”

That figures to happen by Monday or Tuesday. A storm system is approaching the Pacific Northwest coast, and Goss said it could drive down a cold front through the Bay Area.

Measurable rain is likely in the North Bay, where as much as a half-inch could fall, he said. It will be much lighter in the East Bay and South Bay. The temperatures will fall significantly, and the weather will mimic the type of pattern typically seen during the earliest days of spring in late March or early April.

“It’s gonna be more like a tenth of an inch here,” Goss said. “It’s nothing that’s going to cause any flooding concerns, but after a month of no rain, there will be slick roadways and the other usual things you see when you haven’t had rain in a while.”