The San Francisco Bay Area may see a break from the usual warm and dry September weather with an upcoming chance of rain and isolated thunderstorms late Sunday into Monday, according to the National Weather Service (NWS) San Francisco Bay Area. A shift in weather patterns will bring cooler temperatures and breezy conditions throughout the weekend.
Temperatures are anticipated to trend cooler, with coastal areas experiencing highs in the low 60s and interior regions reaching the mid to upper 80s. The Salinas Valley and Monterey Bay are currently sporting a layer of stratus clouds that have rolled back in, contrasting the clear skies seen on previous nights, according to the NWS. A cold front, bringing increased winds, is set to move in, and while it is not expected to deliver substantial moisture, it might just be enough to introduce the fondly-known 'petrichor' - the earthy scent produced when rain falls on dry soil.
With the front's arrival, the possibility of isolated thunderstorms looms, particularly late Sunday and into Monday. There's a 10-15% chance across the region for such phenomena, which could also bring lightning and gusty winds, posing potential risks such as fire starts from lightning strikes. Residents are reminded to head indoors when hearing thunder, a safety tip circulated by NWS San Francisco Bay Area advising, "when thunder roars, go indoors! Or, see a flash, dash inside!"
Regarding precipitation, the Bay Area and north Central coast have been depicted in light green on the NWS Weather Prediction Center's 7-day forecast through 5 PM PDT September 20. The NWS Bay Area on Twitter notes that, given September is typically the third driest month of the year, like October, it usually is warm/hot and dry with offshore winds here. With the current forecast, it won’t take much for this month's rainfall totals to reach the normal September precipitation levels.
NWS WPC 7 day precipitation forecast thru 5 PM PDT Sep 20, 2024. Light green ~ Bay Area & north Central coast. Sep typically 3rd driest month of year like Oct it's usually warm/hot & dry w/ offshore wind here. Next week's #CAwx, won't take much to reach normal Sep precipitation. pic.twitter.com/h6N83kMRgZ
— NWS Bay Area 🌉 (@NWSBayArea) September 14, 2024
As conditions return to normalcy after Monday, high temperatures are expected to sit around 15 degrees below normal with highs mainly in the 60s before moving back to the 70s in the interior as the low-pressure system moves out. Another system will be quick on its heels midweek, bringing another chance of light rain. As we move towards next weekend, ensemble guidance indicates a shift from troughing to ridging suggesting a possible return to warmer weather, as highlighted by the NWS. The Bay Area's residents should stay tuned for further updates as these prediction models continue to evolve.
