San Francisco Bay north of the Bay Bridge, including San Pablo Bay, Suisun Bay, and West Delta, CA Marine Forecast
|Rest Of Today...Sw Winds 5 To 15 Kt.|
|Tonight...Sw Winds 5 To 15 Kt.|
|Tue...Sw Winds 5 To 15 Kt With Gusts Up To 25 Kt.|
|Tue Night...Sw Winds 5 To 10 Kt With Gusts Up To 25 Kt.|
|Wed...Sw Winds 5 To 15 Kt With Gusts Up To 25 Kt.|
|Wed Night...W Winds 5 To 15 Kt.|
|Thu...W Winds 15 To 25 Kt With Gusts Up To 30 Kt.|
|Fri...W Winds 10 To 20 Kt With Gusts Up To 25 Kt.|
| 226 PM PDT Mon Sep 21 2020 |
Synopsis for the Central California Coast and Bays Including the Monterey Bay, Greater Farallones and Cordell Bank National Marine Sanctuaries - PZZ500
Winds have increased out of the northwest over the northern waters and along the Sonoma County Coast. The inner coastal and southern waters will increase later today before breezy winds subside over the outer waters tomorrow. Mixed seas will persist with a shorter period northwest swell and a long period southwest swell. A more robust northwest swell will arrive across the waters by Friday morning.
| Area Forecast Discussion|
National Weather Service San Francisco Bay Area
535pm PDT Monday September 21 2020
.SYNOPSIS..A seasonable weather pattern through midweek with temperatures running near normal. A dry cold front passes through the Bay Area on Thursday that will keep persistent onshore winds in place into Friday. Dramatic change in store for the weekend as high pressure quickly builds with increasing offshore wind pattern. Temperatures rapidly warming over the weekend with periods of offshore winds that will increase fire weather concerns as hot afternoons, low humidity and breezy offshore winds coincide. Strong ridge to stay in place at least through early next week.
as of 2:19pm PDT Monday...Todays focus has actually been on the long range forecast and its potential impacts this weekend with less focus on the short term.
Short term: Marine layer locally just over 1200 feet with low clouds confined to the Monterey peninsula this afternoon while all other locations remain sunny. 24 hour temp trends show significant cooling compared to Sunday afternoon with most places running 4-8 degrees cooler while Watsonville and Salinas are running close to 20 degrees cooler. Weather pattern tonight through Weds will be zonal/onshore with some shortwave ridging by Weds. This should translate to seasonable temps with 70s/80s inland.
By Thursday a cold front will move into Northern California. Any rain looks to stay from Mendocino northward with perhaps some coastal drizzle, especially for the Sonoma coast on Thursday. Behind the front persistent onshore winds and lowering heigheights on Friday will keep temps running near to slightly below normal.
All attention then turns to the weekend forecast. Confidence increasing for potentially significant offshore wind event. Temps will warm rapidly on Saturday with highs bouncing well back into the 80s and lower 90s as a 594dm high builds off the coast with some offshore winds near the surface. Ensemble solutions remain consistent with building ridge leading to hotter temps and stronger offshore winds into Sunday. Would expect widespread highs into the 90s and even some lower 100s. The dry airmass will allow for decent night time cooling that should preclude widespread significant heat impacts though even the overnight lows will remain warmer than normal where the offshore winds blow all night.
Right now the peak of the winds looks to be Sunday morning for the North and East Bay hills but still several days out to dial in the details and exact timing. Confidence is high overall and Sunday does look to be hotter than Saturday as heigheights builds to at least 596dm with persistent offshore/drying winds. Interestingly enough the pattern looks to take hold for several days with the ridge anchored along the West Coast at least through Weds of next week. Right now the only hope of cooling looks to be a southerly wind reversal along the coast.
as of 02:26pm PDT Monday...Winds have increased out of the northwest over the northern waters and along the Sonoma County Coast. The inner coastal and southern waters will increase later today before breezy winds subside over the outer waters tomorrow. Mixed seas will persist with a shorter period northwest swell and a long period southwest swell. A more robust northwest swell will arrive across the waters by Friday morning.
.BEACHES...as of 02:34pm PDT Monday...A larger northwest swell arrives late Thursday evening and into Friday morning. The main impacts will be increased wave heigheights breaking near the shoreline and an increased risk of rip currents developing along coastal beaches. With the increase in temperatures inland expected this weekend, beachgoers should be mindful of the increased wave activity and rip currents. The wave activity is forecast to gradually decrease through the weekend, but caution is advised through at least Sunday morning.
.MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm until 9 PM SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM