FXUS66 KMTR 271758
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1058 AM PDT Mon Apr 27 2026
...New SHORT TERM, LONG TERM...
.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
restabilize.
&&
.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...
(18Z TAFS)
Issued at 1030 AM PDT Mon Apr 27 2026
In the wake of the surface trough there are numerous cumulus
clouds across the cwa. Most of these clouds have bases in the low
VFR range and the coverage should scatter out as the day goes on
and drier air continues to filter in. As the lower atmosphere
stabilizes overnight there is a good chance for MVFR stratus to
develop across all terminals.
Vicinity of SFO...Winds will gradually increase to a moderate
westerly breeze this afternoon with persistent scattered clouds
that may occasionally form a low VFR ceiling. The winds will
decrease overnight and there is a 50% chance for an MVFR ceiling
between 12Z and 16Z Tuesday morning before the clouds clear.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...There is still an outside chance for a
quick shower at the southern terminals, but the radar activity is
greatly waning. The associated ceilings will linger through the
day, but shouldn't drop to MVFR until tonight.
&&
.MARINE...
(Today through Saturday)
Issued at 1030 AM 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 9 AM PDT
Wednesday for Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...Flynn
MARINE...Flynn
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Prepared by Boulder-Creek.com Weather at: Mon Apr 27 16:30:03 PDT 2026
From the National Weather Service
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