Issued at 903 AM PST Wed Nov 12 2025
Light rain is falling over the North Bay, with generally less than 0.05" over the past 3 hours in the higher terrain across the region and along the coast. This is as the warm a result of orographic lift as southwesterly winds continue to increase ahead of our main frontal system that will move through the region late tonight and into the morning on Thursday. The ongoing forecast remains on track with no updates anticipated at this time. Look for a full forecast update by 3 PM this afternoon.
RGass
, Issued at 414 AM PST Wed Nov 12 2025 (Today and tonight)
The picture from space this morning is absolutely mesmerizing. You can clearly see the upcoming pattern change. High clouds continue to stream in ahead of a deepening upper level low over the Pacific. Radar shows light echos passing over portions of northern and central CA at this time; however, soundings show a decent dry pocket beneath the high clouds. Chances for rain will slowly increase throughout the day, from north to south. The more prominent time for rain will begin late tonight and into Thursday as the continues to deepen and dig southwards as it moves towards the west coast. What we can expect moderate to potentially heavy rain at times, and perhaps a few rumbles of thunder. In terms of rainfall totals from 4AM this morning to 4AM Friday, the forecast amount has come up. The North Bay will see between 1.25-5.0 inches, with the larger amounts occuring in the higher portions of the and orographically favored terrain. East Bay amounts vary from 0.75-2.25 inches with the higher amounts expected over the terrain. From the San Francisco Peninsula, Santa Cruz, and into the South Bay look for 1.25-3.5 inches. And finally for Monterey and San Benito amounts vary from 0.75-5.25". With that being said, the WPC has added a Slight Risk of heavy rainfall around the Bay Area which may lead to poor drainage and urban flooding due to runoff. This matches well with some of the hi-res models and HREF where it pinpoints the potential for flooding parts of northern California. For those commuting in the morning, be prepared for rain and consider allowing extra time for your commute.
In addition to the rain, this system is expected to pack a potent punch with winds. The strongest winds will be along our coastline, especially from the North Bay Coast, including the Marin Hills, down the San Francisco Peninsula. Here we can expected to see wind gusts reaching 55 to 60 miles per hour, with gusts up to 70 mph possible at favored coastal and higher terrain locations. A High Wind Warning will go into effect from 10 PM tonight through 10 AM Thursday morning. Elsewhere a Wind Advisory remains in effect from 10 PM tonight through 10 AM Thursday morning 15 to 25 mph with gusts up to 45 mph.
..issued at 414 AM PST Wed Nov 12 2025 (Thursday through Tuesday)
As the front works its way through the region, we'll be left with post-frontal showers in its wake. An upper level trough looks to meander over southern CA through Friday, and perhaps into the weekend. Ensemble guidance shows either shows troughing or weak zonal flow through early next week. This should lead to cooler weather and unsettled weather.
(18z TAFS) Issued at 924 AM PST Wed Nov 12 2025
Currently VFR at all terminals with the exception of SJC which has a high-end MVFR ceiling. Low-end VFR ceilings will prevail today. Rain showers are approaching the region from the southwest, so these can be expected to make a run at the terminals this afternoon. Rain showers will increase in coverage and intensity overnight with the cold frontal passage. Southerly winds will increase ahead of the cold front, becoming the strongest and gustiest during the passage. An embedded thunderstorm cannot be ruled out, but confidence is too low in timing and location to include in the TAF. No definitive low-level wind shear, but bumpy conditions can be expected. During the time of heaviest rainfall, MVFR conditions can be expected to prevail with further deterioration possible.
Vicinity of SFO, Currently VFR with southerly flow. Low-end VFR ceilings will prevail today. Southerly winds will increase through the day, becoming gusty this afternoon. Rain showers are expected by mid-afternoon, increasing in coverage and intensity overnight with moderate rain expected by mid-morning. Conditions improve towards the end of the 30 hour TAF period.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Currently VFR and calm at MRY and VFR with moderate drainage flow at SNS. Low-end VFR ceilings will prevail today. Southerly winds will increase through the day, becoming gusty this afternoon. Rain will approach the terminals towards the end of the TAF period with the heaviest rainfall for the terminals expected in the next TAF period.
(today through Monday) Issued at 903 AM PST Wed Nov 12 2025
Widespread hazardous marine conditions will develop this afternoon with conditions deteriorating through tomorrow morning. Rain showers this afternoon will increase in coverage and intensity tonight into tomorrow morning with embedded thunderstorms possible. Widespread gale force gusts are expected tonight through tomorrow morning with storm force gusts expected for the northern waters. Winds will quickly diminish Thursday night. Moderate seas today will build to become rough for the inner waters and very rough for the outer waters Thursday through Friday. Seas abate to become moderate by Saturday.
Issued at 414 AM PST Wed Nov 12 2025
Wave bulletins recently are showing potential for hazardous surf conditions developing late to very late Thursday night and Friday. However, currently it's a low confidence forecast as to whether we'll reach beach hazard criteria or possibly high surf advisory criteria. Complicating the forecast is in situ rapidly deepening low pressure development 400 miles northwest of San Francisco that has itself rapidly evolved just since the weekend, and part of potentially hazardous surf may be related to the local wind field in the vicinity of the storm developing in the nearest term. Wave model forecasts also currently show much of the wave energy over the offshore waters passing by to our west late this week which may help mitigate coastal hazards. Please stay tuned to further updates.
Ca, High Wind Warning from 10 PM this evening to 10 AM PST Thursday for CAZ006-502-505-509.
Wind Advisory from 10 PM this evening to 10 AM PST Thursday for CAZ503-504-506-508-510-512>518-528>530.
PZ, Small Craft Advisory until 3 PM PST this afternoon for Mry Bay- Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.
Gale Warning from 3 PM this afternoon to 9 AM PST Thursday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-SF Bay N of Bay Bridge.
Gale Warning until 9 PM PST this evening for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Storm Warning from 9 PM this evening to 9 AM PST Thursday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.
Gale Warning from 3 PM this afternoon to 9 PM PST this evening for Pt Reyes to Pigeon Pt 0-10 nm.
