A winter weather advisory was in effect in the Sierra Nevada from 5 a.m. Wednesday until 8 a.m. Thursday. The Bay Area saw a second consecutive day of rainfall, with Wednesday’s precipitation expected to exceed Tuesday’s totals, according to the National Weather Service.

Rainfall Totals and System Details

By 2 p.m. Wednesday, Mount Hamilton recorded approximately half an inch of rain. Ben Lomond and Mt. Umunhum in the Santa Cruz Mountains received about a third of an inch, while downtown Oakland saw three-tenths of an inch. Concord received two-tenths of an inch, and San Francisco and San Jose airports recorded .05 and .02 inches respectively.

The current system is a result of a disturbance spinning off the main band of a storm originating from the Gulf of Alaska. It began impacting the North Bay late Wednesday morning, with increasing intensity expected overnight for the rest of the region.

Shift to Warmer Temperatures

Following the rain, high barometric pressure is building, promising the return of sunshine and warmer temperatures. National Weather Service meteorologist Dylan Flynn stated on Wednesday afternoon, “This high pressure is going to be more progressive. It’s not gonna hang around any more than a week. It’s probably just a few days before another trough comes through again.”

March's Record-Breaking Heat

The anticipated warming trend comes after a historically warm March. The weather service reported that 12 of its 13 climate sites recorded the highest temperature anomalies for any month since record-keeping began. Every climate site also experienced its warmest March ever, with average temperatures rivaling those typically seen in April.

Flynn explained, “That heat assimilation is a real thing. The actual standard we use for issuing heat advisories is higher in the summer, because our bodies are used to it. It was hard to be ready for that.”

Weekend Forecast

While the weekend heat isn’t expected to reach the extremes of March, temperatures are forecast to rise. Areas of the South Bay and the interior East Bay could reach the 80s. Oakland is predicted to reach 75 degrees Fahrenheit by Saturday, with similar temperatures expected along the Peninsula. San Francisco may see temperatures around 70 degrees Fahrenheit.

Sierra Nevada Conditions

The Sierra crest is expected to receive 6 to 12 inches of snow before Thursday, with 1 to 3 inches at lower elevations near Lake Tahoe. Lake Tahoe is anticipated to experience waves between 3 and 6 feet high, and wind gusts of up to 100 mph at ridge tops, and 45-55 mph at lower elevations.

Caltrans implemented chain controls on eastbound Interstate 80 at Applegate and screened westbound trucks west of Reno. Permit loads were prohibited in both directions, while State Highway 50 remained open without restrictions as of Wednesday afternoon.