, Issued at 327 AM PST Thu Dec 4 2025 (Today and tonight)
Longwave pattern over the EPac through Plains is complicated with: two upper lows (one west of Baja and the other east of Hawaii), a large area of high pressure off the CA coast extending into the PacNW, and a shortwave trough sweeping through the 4-corners. Despite the complexity, pretty quiet weather across the Bay Area and Central Coast with minor to moderate impacts. Satellite imagery continues to show widespread mid-high level clouds streaming the northern periphery of the ridge and spilling over the Bay Area. The high clouds initially limited radiational cooling, but gradual thinning over the last few hours had led to a steady drop in temperatures. A Cold Weather Advisory has been issued for the North Bay Valleys, and Interior Central Coast (S Monterey/San Benito) through 8 AM for cold temps 33 to 36 degrees. Even seeing a few 20s across interior San Benito. This is the first Cold Weather Advisory of the season. Areas outside of the advisory are chilly and in the upper 30s and 40s - low 50s coast. Winds were stronger yesterday, but still seeing some gusty winds in the hills of the North Bay with Mt St Helena still shows gusts 35-45 mph. The larger offshore gradient is still on track to relax during the afternoon leading to weakening winds over the North Bay Mts. Despite the chilly start in some locales, today's temps will warm into the 50s and 60s or seasonal averages . One last item in the near term is pesky Tule Fog developing in the Central Valley again. Fog was initially slow to get going (likely due to some of the high clouds), but now it's in full force in the West Delta and interior East Bay Valleys. Clouds and locally dense fog will be the main impacts.
For tonight, slight warm up, but still chilly across the interior. Coldest temperature will be over the interior Central Coast and therefore have extended the Cold Weather Advisory through Friday 8 AM for that location with lows in the 33 to 36 degree range.
..issued at 400 AM PST Thu Dec 4 2025 (Friday through Wednesday)
The ridge to our west shifts east Thursday night into Friday. As such, a gradual warming of the airmass is expected. Still a chilly start to the day Friday, but afternoon temperatures will rebound and be up 3-5 degrees from Thursday. Additional warming is expected over the weekend. One other thing we'll be keeping an eye on heading into the weekend will be precip chances. A few weak systems pass to the north and get buffeted by the ridge overhead. As such, precip chances remain highest north of the region. The exception will be tail ends of decaying cold fronts bringing precip chances to the coastal waters Friday and Saturday.
The ridge does flatten, but then remains parked off the SoCal coast through the middle of next week. That means high and dry conditions for the Bay Area and Central Coast. Interior Central Coast may even hit the mid 70s by next Wednesday.
Longer range ensemble guidance better precip return by the middle of the month.
(12z TAFS) Issued at 327 AM PST Thu Dec 4 2025
VFR through the TAF period. Light to moderate easterly winds last through the morning before winds turn north to northwest into the afternoon for all but the North Bay and LVK, which stay easterly. Winds reduce again into the evening, becoming light for the night.
Vicinity of SFO, VFR through the TAF period. Light and variable winds turn moderate and northeast into the mid morning. Expect winds to turn north-northwest in the mid to late afternoon, then more westerly into the night as winds reduce.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR through the TAF period. Light to moderate southeasterly winds last through much of the morning before becoming northwesterly into the afternoon. Winds weaken and become light and variable into the evening and through the night.
(today through Tuesday) Issued at 327 AM PST Thu Dec 4 2025
Winds and seas are easing. Expect mostly calm conditions into the night before breezy to gusty northwest winds return with rebuilding seas up to 8 feet. Winds stay breezy into the next work week, but seas abate in the early week.
Ca, Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508- 529-530.
Cold Weather Advisory until 8 AM PST Friday for CAZ516-518.
PZ, Small Craft Advisory from 9 AM Friday to 3 AM PST Saturday for Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 9 PM this evening to 3 AM PST Saturday for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 3 AM Friday to 3 AM PST Saturday for Pigeon Pt to Pt Pinos 10-60 NM.
