Issued at 819 AM PST Sun Mar 1 2026
The broad view on satellite shows a low pressure system spinning off the NorCal coast. Ahead of this system, clouds continue to stream over the Bay Area and Central Coast. A shallow stratus also move inland ushering in low clouds and patchy fog along the coast and locally inland this morning. Lastly, if you looked at the KMUX radar imagery you probably noticed a few echoes. Despite echoes, nothing is reaching the ground just yet. Morning sounding from KOAK shows a rather dry column in the atmosphere. We'll need to moisten up the column before anything hits the ground.
For the rest of the day, the upper low will continue to inch its way toward the coast. As such, we'll hold onto clouds this morning and into the afternoon. There is some clearing/scattering potential late this afternoon. As for precip, still looking like this evening and overnight with highest confidence north of the Golden Gate. Temps for today int he 60s and low 70s or seasonably mild.
No updates needed.
MM
, Issued at 449 AM PST Sun Mar 1 2026 (Today and tonight)
The SFO-SAC pressure gradient is 1.9 mb. Fresh onshore winds from the surface through the lower levels of the atmosphere continue to bring cooler air inland. Satellite shows areas of low clouds forming in the cooler air intrusion across the Bay Area and north Central Coast. Mid to high level clouds continue to move in from the southwest. 24 hour surface temperature trends are solidly cooler including across the higher elevations with widespread 50s and a few spots in the mid to upper 40s. 500 mb height ridging is to our east. A closed 500 mb low is ~ 500 miles west-northwest of San Francisco and it's forecast to move east across northern California tonight and Monday morning. Cooler air with the low will bring a chance of wet weather and a slight chance of thunderstorms mainly tonight and Monday morning.
..issued at 449 AM PST Sun Mar 1 2026 (Monday through Saturday)
Light measurable precipitation chances from the North Bay to the San Francisco Peninsula, including part of the East Bay south to the Big Sur Coast Monday morning decrease by Monday afternoon. 500 mb height ridging arrives from the west Monday night and Tuesday. Cooler air with surface high pressure arrives Wednesday night and Thursday morning. From mid to late week surface high pressure over the eastern Pacific will steadily strengthen bringing our coastal waters gusty northwest winds with land overlap of gusty northwest winds. For Friday and Saturday recent ECMWF and GFS ensemble means forecast a 7 mb to 9 mb WMC-SFO pressure gradient supporting moderate offshore winds. Guidance shows 925 mb and 850 mb northerly to northeasterly winds increasing from mid to mostly late week. If this synoptic pattern verifies it would result in dry conditions and downsloping gusty winds to the coastline with the potential for larger diurnal temperature ranges from cool/chilly morning lows (if the valleys decouple from winds aloft) to ~ 10F above early March normal daytime highs to the mid to upper 70s if not Friday then Saturday perhaps on Sunday too.
(18z TAFS) Issued at 950 AM PST Sun Mar 1 2026
A weak system spinning off the NorCal coast and ample onshore flow led to a mixed bag early this morning with IFR to VFR conditions across the terminal sites. Have seen gradual improvement over the last hour or two and expect this trend as low stratus breaks up and low to mid cigs begin to scatter. The back edge of SCT is becoming more apparent over the coastal waters and expect that to move inland this afternoon. Therefore, mostly VFR this afternoon. Tonight, a transition IFR with DZ or -SHRA BR and lower cigs most terminal. Best chc for precip will be coastal sites and N Bay.
Vicinity of SFO, VFR to MVFR through 19-20Z then VFR. IFR redevelop tonight with -DZ lingering into the AM rush. Tail end of the AM rush transitioning back to VFR
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Ample high clouds will limit clearing potential in the AM and into afternoon. Keeping MVFR to IFR through the period.
(today through Friday) Issued at 819 AM PST Sun Mar 1 2026
A weak storm system passing through Northern California will bring a chance of showers and a slight chance of thunderstorms late tonight into Monday morning. High chances for precipitation will be north of the Golden Gate. Seas continue to weaken until mid- week. However by late week, high pressure strengthening over the eastern Pacific will likely result in northwest winds to gale force and steepening seas over 12 feet.
Ca, None. PZ, None.
