Bay Area Rain Chances Wednesday; More Snow Forecast In The Sierra

SAN FRANCISCO — The Bay Area could see a few rain showers Wednesday amid a fall-like turn in the weather, and an unusually early brush with winter is underway in parts of the Sierra.

The National Weather Service's Bay Area office recorded some light drizzle Tuesday and forecasters expect much of the region will have another shot Wednesday as temperatures continue to run 5 to 15 degrees below seasonal normals.

"Another upper-level low will approach the coast tonight and move across on Wednesday bringing generally light rainfall to the region," NWS Bay Area said Tuesday afternoon. "Rainfall amounts are expected to be light, not amounting to more than [0.10 inches] in most locations, except for locally higher totals in the coastal ranges or where any stronger showers develop."

Forecasters said there was a 15 percent chance for thunderstorms to develop in the North Bay, with a "non-zero" chance elsewhere in the Bay Area. Afternoon highs should continue to run cooler Wednesday, ranging from the low 60s in Half Moon Bay to the upper 70s around Concord and San Rafael.

Up in the mountains, the Sierra kicked off the week with a rare dusting of September snow, and another wintry blast is in the forecast through Thursday. According to the San Francisco Chronicle, the National Weather Service on Friday issued its earliest winter weather advisory in two decades over the weekend, covering high elevations of Yosemite, Kings Canyon and Sequoia National Parks.

Photos and videos shared on social media showed snow falling on Tioga Pass and at June Lake on Monday. The weather service said Tioga Pass had a 75 percent chance to pick up more than 3 inches of snow Thursday morning, and metrologists told the Chronicle higher elevations in Alpine and Mono counties could see similar outcomes.

Forecasters expect a warmer, drier trend will get underway heading toward the weekend and expect to welcome the autumnal equinox Sunday with temperatures close to their seasonal normals.