Bay Area rain lingers longer than expected, but sun is coming

Morning commuters through much of the Bay Area were greeted Thursday with wet roads and steady showers, a surprise given that the National Weather Service figured that a low-pressure system from the north would move out of the region.

Instead, it barely moved Wednesday.

“It’s still lingering,” NWS meteorologist Roger Gass said. “That’s what’s resulting in the rainfall, and those rain chances are going to continue for much of (Thursday).”

The rain is expected to be steady if not real heavy, according to the weather service, though it could spawn a thunderstorm or two and periods of heavy rainfall, Gass said.

Conditions were extreme near the water and the weather service issued a warning for hazardous beach conditions beginning at 9 a.m. Thursday and lasting until 3 a.m. Friday. Sneaker waves and strong rip tides are likely.

The rain fell harder overnight than it did during much of Wednesday. By 6 a.m., the weather service’s 24-hour rainfall totals showed more than one-third of an inch of rain on Mount Hamilton in Santa Clara County, as well as about a quarter-inch at Ben Lomond in the Santa Cruz Mountains. The North Bay also was soaked, with four-tenths of an inch falling in Petaluma.

Elsewhere, the rain was considerably lighter. About two-tenths of an inch of rain fell in Hayward, one-tenth fell in Livermore and about four-hundredths of an inch fell in San Jose and in Concord.

“It should start winding down by (Thursday) afternoon or evening,” Gass said. “There’s an ever-so-slight chance that it could go into late in the night or into (Friday) morning in the North Bay.”

The system also is expected to drop more snow into the Sierra Nevada. Up to two inches of snow were expected above 7,200 feet, according to the weather service. Snow flurries began at that elevation on Wednesday.

As the low pressure moves — slow as it might be — a jetstream flow from sub-tropical low pressure is expected to create gusty winds from the ocean that could gust as high as 30-35 mph, Gass said. That sub-tropical moisture was an an element that contributed to the rainfall early Thursday, Gass said.

By the weekend, that wind will come amid ever-increasing temperatures. The weather service still expects the temperatures to hit 80 degrees in the hottest places and 75 degrees in many others by Sunday, figures that are expected to increase by 3-5 degrees into the next work week. Temperatures near the water are expected to remain cool, with Oakland, San Mateo and San Francisco not expected to get much past 70 degrees.