For Bay Area weather, a repeating cycle: Rain and cold, damp and dry
A gray, overcast Friday was set to kick off a weekend that is likely to see a bit of a dry period and then some more rain — all of which will lead to an early work week that will see a bit of a dry period and then some more rain.
“A couple of these systems out ahead of us [on the calendar] have started to trend drier,” National Weather Service meteorologist Roger Gass said. “But it’s still going to rain. It’s too far out time-wise to know when there’s going to a significant change.”
A brief warm-up earlier this week set off a bit of a false indicator that the inclement weather may be gone for a while. Gass said that in actuality, the current weather pattern that began dropping rain into the region on Thursday is in keeping with how many early spring patterns behave.
That means lingering showers are likely for most of Friday and then a mostly dry Saturday before the next rain probably starts to fall Saturday night and lasts into Sunday, according to Gass. A storm on Tuesday into Wednesday follows the weekend rain after another day of a cold, cloudy dry day is expected Monday into Tuesday.
“Those amounts (Friday into Saturday) generally will be less than 15-hundredths of an inch for the Bay Area, and maybe one-third of an inch in the North Bay,” Gass said. “We still have decent rainfall amounts possible for Tuesday into Wednesday, but again, I expect those to trend downward.”
The reason, he said, is that the low pressure has dipped deeper than originally anticipated, thus shifting the entire system further to the south. That shift has begun to show on European weather forecast models that are now forecasting considerably less rain and is also beginning to appear on some U.S. models, Gass said.
Light snow is expected to fall in the Sierra Nevada through early Saturday, mainly over its highest passes. The weather service said 4-6 inches of snow are expected in areas of Donner Summit and other locations above 5,600 feet. Other areas of Donner Summit are expected to receive 2-3 inches, while Truckee is not expected to receive more than an inch.
The rain that began to fall Friday was heaviest on Mount St. Helena in Napa County and Mount Umunhum in Santa Cruz County, where the 24-hour totals at 9 a.m. showed about a half-inch and four-tenths of an inch respectively. Areas of Orinda received .32 inches and areas of Marin County received a quarter-inch. Downtown Oakland saw .07 inches. No measurable rain fell in San Jose, and other areas of the South Bay received no more than .09 inches.
The temperatures continued to hover with highs in the low 60s and lows in the low 40s, and that won’t change over the next week, Gass said. Dangerous waves that may break up to 30 feet also will continue along the coast, and the weather service extended a high surf advisory through Friday.