FXUS66 KMTR 272343
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
443 PM PDT Mon Apr 27 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1055 AM PDT Mon Apr 27 2026

 - Warming and drying trend kicks off Tuesday, peaking Thursday
   and Friday

 - Cooler conditions return this weekend with a chance of rain

&&

.SHORT TERM...
Issued at 1055 AM PDT Mon Apr 27 2026
(This afternoon through tonight)

Isolated light rain showers are continuing with the help of remnant 
surface troughing across the Bay Area. Activity will wane this 
afternoon, giving way to a mix of sun and clouds and below normal 
temperatures. With remnant moisture, low clouds will return to 
bayshore and coastal locations tonight as the lower levels 
destabilize.

&&

.LONG TERM...
Issued at 1055 AM PDT Mon Apr 27 2026
(Tuesday through Sunday)

The upper-level troughing that brought us light rain over the 
weekend will pinch off a cutoff low as upper-level longwave ridging 
moves in from the Eastern Pacific Ocean. This will result in a 
warming and drying trend with temperatures rebounding to near to 
slightly above normal. The warmest day of the week will be on 
Thursday for the Bay Area and Friday for the Central Coast. The 
locations of the two features, ridge over the Pacific Northwest and 
low off the coast of Southern California, will support light 
offshore flow during the overnight hours. Subsidence aloft and 
offshore flow in the higher terrain will likely yield a shallow 
marine layer that will only impact coastal locations. Global 
ensemble clusters are in agreement that the ridge will get tamped 
down by an approaching upper-level trough as we approach the 
weekend. There is some uncertainty on how we get there, but by 
Sunday it is likely that there will be an upper-level low off the 
California Coast. While there's no measurable precipitation in the 
forecast right now, this will renew chances for rainfall as we head 
into next week.

&&

.AVIATION...
(00Z TAFS)
Issued at 437 PM PDT Mon Apr 27 2026

VRF through the evening rush. CU field across the region is
thinning as the sun sets. Expect VFR to persist into the first
part of tonight. A more stable lower level and weak flow will lead
to stratus develop tonight. Lower confidence for stratus develop 
is SJC, but enough prob guidance hints to justify a mention. Late 
morning clearing for stratus on Tuesday. Breezy to gusty onshore 
winds will lingering through early Monday evening.

Vicinity of SFO...VFR through most of tonight with clouds
reforming near 10Z Tuesday. Onshore gusts of 20-25 kt through 
Monday evening then decreasing overnight and then another push
Tuesday afternoon.

SFO Bridge Approach...VFR. Some MVFR patchy cigs may impact
portions of the approach early Tuesday.

Monterey Bay Terminals...VFR. Latest guidance does bring some 
MVFR cigs back, but late tonight and more so Tuesday AM.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 437 PM PDT Mon Apr 27 2026

Moderate NW winds will persist through Tuesday before gradually
increasing to a fresh to strong breeze Wednesday through Friday.
These stronger winds will build rough seas of 8-12 feet across
exposed waters.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 PM this evening to 3 PM PDT 
     Wednesday for Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...MM
MARINE...Flynn

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Prepared by Boulder-Creek.com Weather at: Mon Apr 27 20:30:03 PDT 2026