The Bay Area experienced a bout of inclement weather as a cold front swept through on Sunday night, bringing widespread rain and strong winds that persisted into early Monday morning. The National Weather Service (NWS) San Francisco warned of gusty winds, the potential for thunderstorms, and nuisance flooding. Commuters were advised to allow extra travel time on Monday morning and to avoid flooded roads.
Heavy downpours were present, with the NWS San Francisco noting "several cells over the coastal waters have displayed rotational velocity of 30kts, indicating a legitimate waterspout potential." Despite the waterspouts typically losing structure as they neared shore, the possibility of damage along the coast from San Mateo to Monterey County remained. The weather system also brought intense rainfall, with Marin County spotters reporting rapid accumulations that heightened the risk of landslides, particularly over the Pickett Burn Scar, where a flash flood warning was in effect.
As the cold front advanced, the region prepared for more unsettled weather. "A strong cold front is moving through early Monday morning," reported the Area Forecast Discussion from the NWS San Francisco, mentioning forecasts of scattered showers which were expected to taper off throughout Monday. The same forecast discussed clearer conditions arriving on Tuesday, with the next system projected to bring milder rainfall from late Wednesday through Thursday. This interlude offered a respite from the more severe conditions experienced over the last 24 hours.
Maritime conditions echoed the turbulence found on land. The NWS advised that a cold front had led to gale-force gusts overnight and switched to a moderate westerly breeze by morning. Boaters were warned of strong northwest winds through Tuesday, which would generate rough seas. Calmer conditions were on the horizon for Wednesday and Thursday, but a strong western northwest swell was anticipated to arrive by the end of the week, keeping the marine weather watch on high alert.
In terms of the daily outlook, the detailed forecast for San Francisco provided by the NWS revealed rain likelihood before 4 pm on Monday, turning into a chance for showers and thunderstorms later in the evening. While conditions were expected to be mostly cloudy with highs near 60, the possibility of precipitation sat at 70 percent. For Tuesday, the skies were predicted to be mostly sunny, with similar highs, and a gentle northerly wind shift in the afternoon.
