Monday is expected to offer the Bay Area its cleanest window before the storm: mostly sunny skies, building clouds and temperatures ranging from the low 60s near the coast to almost 70 inland. One forecast urged residents headed to the polls Tuesday to “pack an umbrella and a raincoat” — or vote early or use a ballot drop box on Monday.¹

That advice is already resonating beyond the forecast maps. Elon Musk reposted an early voter’s account of a line that “wraps through the building and pushes outside,” adding that it was raining and the voter was “staying in line.”Elon Musk (elonmusk)²

Tuesday morning: The first wave is expected to reach the North Bay coast after 5 a.m., spread to Santa Rosa, Petaluma and Novato by about 8 a.m., then move into San Francisco, the Peninsula and East Bay. The South Bay may get lighter rain and longer dry breaks. The steadiest showers could coincide with the morning commute, with isolated heavy downpours possible along the Marin coast.³

Tuesday afternoon: The first cold front should move east, leaving a temporary lull for much of the region. But the break will be cool, cloudy and gusty rather than genuinely settled. Forecasts put the North Bay’s total rainfall at roughly a quarter- to half-inch, versus about a tenth of an inch in San Jose and the Santa Clara Valley.¹

Tuesday evening: The greater concern comes as the storm’s low-pressure center approaches. Stronger showers, isolated thunderstorms and intermittent downpours could hit during the evening commute — uncomfortably close to poll-closing time. Warm coastal waters may add moisture to the system, though forecasters stress that the precise timing and placement of the heaviest cells remain uncertain.¹

Rain should fade from north to south after sunset, setting up a fast turnaround: Wednesday is forecast to be dry, sunny and in the mid-60s for the Valkyries championship parade.³