Parade of storms to keep Bay Area wet into next week
The final storm system may be the wettest of the three, as atmospheric river to slam the region
January is shaping up to be a wet month for Northern California
he first in a series of three storms heading toward the California coast is expected to bring widespread precipitation to the Bay Area on Friday, with rain totals ranging from one-tenth of an inch to up to 2 inches in the wettest areas, according to the National. Weather Service.
Gusty winds are also expected Friday but won’t be as strong as last weekend, according to Roger Gass, a meteorologist with the weather service. The winds are forecast to be between 15 mph to 25 mph, with gusts up toe 40 mph.
Some inland locations may receive smaller amounts of rain because of the rain-shadow effect, a condition in which a mountain range or other topographic barrier causes prevailing winds to lose their moisture on the leeward side.
The first storm system, moving east from the Pacific Ocean, may split into two systems and impact both Northern and Southern California, according to the weather service. In the Bay Area, rain is expected to reach the coastal areas as early as Friday morning and then spread inland, Gass said.
It’s possible the southern part of the state receives the brunt of the storm.
“Rainfall totals are going to be difficult to pinpoint,” Gass said.
A one- day drying out period is expected Saturday before the second storm brings another round of rain Sunday. Gass said rainfall totals Sunday should mirror those from the Friday system.
A stronger system expected to reach the Bay Area in the middle of next week has the potential to become a moderate “atmospheric river” storm and be the wettest of
the three storms, according to the weather service.
Gass said it’s too early to call the storm an atmospheric river, but did say the system could “tap into deeper moisture over the Pacific and spread it inland.
“Right now our confidence is low of any type of atmospheric river event,” Gass said.
All of California remains in a precipitation deficit for this time of year, though rainfall totals have been improving with the recent storms. Through Wednesday, San Jose is at 75 percent of its historic rainfall average for this date with 4.49 inches, while San Francisco is at 73 percent with 7.46 inches and Oakland is at 72 percent with 6.57 inches.
So far this January, rainfall totals in some Bay Area are above their month-todate historic averages, in- cluding Napa 4.08 inches (152 percent), San Francisco 1.51 inches (115 percent) and San Jose (1.02, 116 percent). Other cities are just below their month-to- date averages, including Oakland (1.54 inches, 85 percent) and Mountain View (.78 inches, 86 percent).
The recent storms have also delivered several inches of new snow to the Sierra Nevada, boosting the statewide snowpack by about 23 percent in a span of seven days. As of Thursday, the statewide snowpack stood at 90 percent of the historic average, up from67 percent on Jan. 3.
Shasta Lake, the state’s largest reservoir, was 52 percent full Monday, or 81 percent of its historic average for this date. San Luis Reservoir, near Los Banos, was 76 percent full, or 101 percent of its historic average. And Folsom was 33 percent full or 66 percent of its average.