San Francisco starts Wednesday in the low 50s before sunny skies push temperatures up to around 71 degrees. Rain is not expected, but the week comes with a bayshore flood advisory and rising fire-weather concerns in higher terrain.
Sunny Wednesday, Sharper Warm-Up Thursday
Wednesday night will be mostly clear with a low near 53 degrees. Temperatures are expected to peak Friday.
Waterfront Advisory Remains In Effect
A Coastal Flood Advisory remains in effect through 4 p.m. Wednesday for bayshore locations along San Pablo Bay. People near low-lying waterfront areas should use extra caution and follow any posted closures or barricades.
Dry Winds Raise Fire Concerns In Higher Terrain
Elevated to near-critical fire-weather conditions are expected from late Wednesday night through Friday morning, especially in the North Bay Interior Mountains and East Bay Hills. Gusts of 30 to 40 mph are possible, with locally stronger winds on exposed ridges, while dry air and warmer temperatures leave vegetation more vulnerable to ignition.
How Flooding and Fire Risks Fit in Context
High tides can contribute to temporary flooding, but they do not by themselves explain this week's advisory. NOAA says high-tide flooding can occur when rising sea levels combine with local factors such as winds, ocean currents and strong tides, including those associated with full or new moons. NOAA tide predictions can help anticipate tidally driven flooding, though the exact timing of peak water levels depends on real-time weather. Separately from this week's advisory, BCDC developed mapping data to help assess community vulnerability to current and future flooding from sea level rise and storms.
Past fire conditions are not a prediction of current danger: the U.S. Fire Administration's report on the October 1991 Oakland-Berkeley East Bay Hills fire says the fire's advance could not be stopped until wind conditions changed. That past disaster does not mean a fire is forecast now. Separately, The Conversation reported that a study found California's typical summer fire-season onset had shifted earlier by at least one month in most of the state since the 1990s. That statewide historical trend does not predict a fire or explain this week's forecast.
