San Francisco started today under a warm, muggy blanket of coastal fog, keeping most neighborhoods in the mid-50s. The marine layer is expected to mix out through late morning, trading low clouds for partly sunny skies and a high near 69°F this afternoon. It will not stay tranquil for long, though, with showers possible later in the day and a more unstable, thunder-friendly pattern setting up tomorrow through the weekend.
What To Expect Today (Thursday, April 9)
Patchy fog before 7 AM should lift as the morning wears on, with light southwest winds around 2 to 9 mph nudging temperatures into the upper 60s by midafternoon. There is a slight chance of light rain between about 1 PM and 5 PM; most of the city will see only brief, spotty showers, while the North Bay and inland hills have a somewhat higher chance of a rumble of thunder. Aviation forecasters expect SFO to improve to VFR by early afternoon, though low clouds and light rain could redevelop tonight. Local reporting pegs the odds of measurable rain this afternoon at roughly 20 to 25 percent, according to SFist.
Late-Week And Weekend Threats
A slow-moving low-pressure system will boost shower coverage and bring the highest chances for thunderstorms tomorrow and Saturday, April 11, with showers hanging on into Sunday, April 12. Thunderstorms could bring lightning, brief heavy downpours, gusty or erratic winds, and small hail, and forecasters caution that training rain bands could drop locally heavy totals. Through Sunday, most spots are expected to pick up about 0.5 to 1.5 inches of rain, with localized amounts up to 3 inches in the coastal ranges. Mountain snow above roughly 4,000 feet is also on the table. The National Weather Service is also urging mariners to take extra care, noting that thunderstorms over the waters could spin up strong gusts and waterspouts.
Commute And Outdoor Plans
Morning fog will cut visibility along the waterfront and on bridge approaches, so drivers should budget extra time for today's commutes and use lights suited for foggy conditions. If the heavier storms develop tomorrow and Saturday, expect slick streets and the risk of localized flooding in low-lying or poorly drained areas, and make sure outdoor plans include a fallback option.
