As September draws to a close, the Bay Area is bracing for two consecutive storm systems that promise to deliver the season’s first significant rainfall. Meteorologist Nicole Sarment of the National Weather Service shared insights with SFGATE, indicating that the upcoming weather patterns are a result of an active Pacific Ocean.
The initial storm, anticipated to arrive by Monday morning from near the subtropics, will be followed by another system on Wednesday, fueled by a typhoon in the western Pacific. Both systems are set to approach from the Gulf of Alaska, with forecasts suggesting that the North Bay will be the hardest hit, potentially receiving up to an inch of rain by week’s end.
In contrast, the East Bay can expect around a quarter of an inch, while other interior regions might see about a tenth of an inch. San Francisco, in this scenario, could receive approximately half an inch from the combined storms.
Earlier forecasts hinted at the likelihood of thunderstorms following a series of lightning strikes across the Bay Area, but as of Sunday, Sarment noted that the chances of such weather occurring had significantly reduced, estimating they would remain below 15% over land.
Adding to the area’s weather dynamics, wildfire smoke from the Moon Complex in southwestern Oregon prompted an air quality advisory on Saturday evening. However, the incoming storms are expected to improve these conditions. “With an active weather pattern, the atmosphere becomes more turbulent, so we shouldn’t see the smoke linger,” Sarment stated, adding that even if the winds don’t clear the air entirely, the rain will help dissipate it.
While the rain offers potential relief from smoke and drought conditions, forecasters are urging caution for commuters, especially in the North Bay, where the rainfall could create slick roads due to oil and debris separation on pavement. Drivers are advised to reduce speed and ensure headlights are on during inclement weather.
Showers may persist into Thursday, after which warmer and drier conditions are predicted to settle in for the weekend, offering a brief respite before the fall weather settles fully into place. This cycle of rain and sun aligns with the natural rhythms of the region, ultimately contributing positively to both air quality and environmental conditions.