Rain returns to the Bay Area; more on the way Friday

The Bay Area recorded its first widespread, measurable rainfall Wednesday in more than one month, a drizzle that allowed many cities to register a few hundredths of an inch.

And slightly heavier rain is expected Friday morning, which could arrive in time for the morning commute, according to the National Weather Service.

“We are anticipating an upper level system coming off the Pacific that may produce more widespread showers across the region,” Roger Gass, a meteorologist with the weather service, said about the chance of rain Friday. “It definitely has been a dry month. This might be our first and only widespread rain showers for the month of May.”

As of 5:17 a.m. Wednesday, 12-hour rainfall totals around the Bay Area were mostly limited to .05 inch or less, including San Francisco and Santa Rosa, both at .01 inch. A rain station southeast of Moraga was the wettest location with .11 inch.

The light rainfall was expected through midmorning Wednesday before tapering off by the afternoon, according to the Weather Service.

The last measurable widespread rain in the Bay Area was April 16, when San Jose recorded .22 inch, San Francisco .11 inch and Santa Rosa .42 inch. The North Bay also recorded light rainfall on April 28, while most other cities were dry.

Following the chance of rain Friday, a slight warming trend is expected through Memorial Day, with temperatures warming to the upper 70s, Gass said.

“Our warmest spots may hit 80 by Monday,” Gass said.