Bay Area residents will go from soaking up some winter sun to being soaked by one of the winter season’s most powerful storms this week, the latest in a string of rain that has fallen mostly uninterrupted since the start of the month.
“It looks like we might get some rain late Tuesday into Wednesday morning,” National Weather Service meteorologist Dalton Behringer said. “That’s a precursor. The big show starts Thursday.”
The “big show” is an atmospheric river-type system that will dump a torrent of rain that is expected to be reminiscent of one of the late-fall storms that saturated the region. It also will bring up temperatures that were near freezing again early Monday.
Preceding it is a small upper-level low pressure system that has some moisture, not a lot of energy and will drop a small amount of rain as an appetizer, Behringer said.
Put them together, and the higher elevations of the region are likely to see 4 to 6 inches of rain, while the lower elevations are expected to see anywhere from 2 to 3½ inches, according to the the weather service. Rain is expected to fall at least through Saturday.
“This is gonna be one of the bigger events that we’re going to see,” Behringer said.
The region still has not dried out from a series of storms that rolled through last week and created flooding concerns. The last rain fell Thursday, but temperatures that did not escape the 50s and hovered in the 30s at night did not do a lot to dry the saturated vegetation, according to the weather service.
Those temperatures brough a freeze warning and frost advisory again Monday morning, the fourth straight morning with one. They are likely again Tuesday and Wednesday, according to the weather service.
“It may warm up by a degree or two the next couple of mornings,” Behringer said. “But by Thursday morning, it will be noticeably warmer.”
It also will be considerably windier, according to Behringer. Wind gusts are expected to pick up again along the coast with the arrival of the Thursday storm, and are likely to blow between 40-45 mph in the higher elevations.
The weather service said it remains uncertain how the the factors contributing to the Thursday storm will impact the Sierra Nevada, though they already are predicting gusty winds and challenging travel. The weather service said it would have a better idea of how low the snow levels may drop as the storm moves closer to the land.
The stretch of heavy rain follows a nearly monthlong period in January that featured no measurable rain for areas of the Bay Area outside the North Bay.