MONTEREY >> After a brief warmup, cooler weather — and even rain — are set to return to the Bay Area this weekend.

National Weather Service meteorologist Rick Canepa said Friday afternoon that a sharp trough that will lower temperatures and drop cold rain is “on track to arrive Saturday night into Sunday.”

The rain will end a stretch of about two weeks without a significant soaking and will arrive just in time for what is considered the meteorological spring. That time period runs through May 31, a period sandwiched between the three coldest and three warmest months of the year.

Canepa said about half an inch of rain is expected through most of the region, and an inch is likely to fall in the Santa Cruz Mountains, according to Canepa. Very wet snow in the highest mountains, including Mount Diablo and Mount St. Helena, also is a possibility.

Isolated thunder and some lightning strikes also are possibilities, he said.

“Warm air will be surrounding the low to the south,” Canepa said. “It’s unstable mostly in the midlevel (atmosphere), then more stable in the higher levels.”

The overall result will be much colder temperatures in addition to the rain, he said.

Average to slightly below- average temperatures will arrive today and persist into next week, with highs generally in the upper 50s to low 60s, according to the weather service.

Another low-pressure system is expected to arrive Tuesday morning and hang around until Wednesday. Forecasters were keeping an eye on the characteristics of that system.

The cooler and wetter weather follows a brief warmup that saw two Central Coast cities set new daily high temperature records and one Bay Area city tie its previous record.

On Thursday, King City hit 85 degrees, topping its previous record of 83 set in 2002, and Salinas reached 84 degrees, besting its old mark of 82 set in 1992, the weather service said.

Redwood City, meanwhile, tied its previous record of 79 degrees set 93 years ago.