380
FXUS66 KMTR 240443
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
943 PM PDT Mon Jun 23 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 205 PM PDT Mon Jun 23 2025

A seasonal weather pattern will continue much of this week with
temperatures running near normal. Look for warm days followed by
cool overnights as coastal low clouds and fog spread locally
inland night and morning hours while sunny skies will prevail
inland.

&&

.UPDATE...
Issued at 702 PM PDT Mon Jun 23 2025

Satellite imagery shows stratus developing across the coast while
high clouds pass through the North Bay and the SF Bay Area. Have
added a mention of slight chances for coastal drizzle tonight into
Tuesday morning, but the rest of the forecast remains unchanged.
As far as smoke over our region, we did have a high level smoke
plume streaming south from Canadian wildfires this morning, but
with the wildfires over 1000 miles away, relatively small changes
in the upper level flow can significantly impact the smoke
distribution. This appears to have happened this evening, as the
latest satellite imagery has revealed that the smoke plume has
migrated over to the far northeastern part of California and
western Nevada. This is supported by webcams from those regions
showing yellows and oranges in the sky at this point in the
evening, with the sun not quite low enough in the sky for the reds
to really show up.

DialH

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 205 PM PDT Mon Jun 23 2025

Coastal stratus has retreated to the coast with the marine layer
depth just over 1000 feet. Low clouds continue to cover Pt Reyes
and a little eddy outside the Golden Gate has kept a sliver of
fog/low clouds south of Angel Island while areas west of the
Avenues remain cloudy out to Ocean Beach. As of 1 pm we have temps
ranging from the upper 50s at the coast to mid/upper 80s inland.
The synoptic pattern features an upper low near Bakersfield that
is helping to generate some convection over the Southern Sierra
with even some cumulus build ups over the higher terrain of San
Benito county. Surface gradients remain relatively light with
less than 2 mb SFO-Sac and light gradients down the coast keeping
afternoon seabreeze winds a little weaker than normal. For tonight
expect the low clouds along the coast to slowly spread into the
coastal valleys of the Monterey Bay region with not too much of an
inland push for the Bay Area. Overnight lows generally in the 50s
with similar afternoon highs forecast for Tuesday afternoon.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 205 PM PDT Mon Jun 23 2025

A gradual and modest inland warming trend forecast Weds and into
the weekend. 500 mb heights become more zonal by Weds and then
show a weak troughing signal by the weekend but the main message
is no big ridge. Nonetheless inland temps should warm by Thursday
and Friday with inland low to mid 90s becoming more common.
However the overall pattern will continue to feature onshore wind
flow regime keeping the coast and bays mild. As noted this
morning SST are quite cool at around 50-51 degrees.

Long range trends for next week currently show a pattern with a
trough over the Pacific NW that will keep the Four-Corners high
well to our east. So continued near to slightly below normal temps
likely heading into July with no monsoon or precip intrusions
currently portended.

&&

.AVIATION...
(06Z TAFS)
Issued at 943 PM PDT Mon Jun 23 2025

The evening onshore 3.9 mb SFO-SAC pressure gradient predominates
while the marine layer depth along the immediate coastline varies
from 1200 to 1500 feet. Earlier in the evening the Oakland upper
air sounding showed a marine layer depth ~ 400 feet. Stratus and
fog will move inland tonight and Tuesday morning then mix out back
to near the immediate coast Tuesday afternoon, though e.g. HREF
output for Tuesday is showing a high probability IFR ceiling all
day at KHAF. Patchy light coastal drizzle has already developed
with additional patchy light drizzle developing tonight and
Tuesday morning. Stratus, fog and possibly patchy light drizzle
return Tuesday night and early Wednesday.

Vicinity of SFO...VFR, then MVFR 09z-17z tonight and Tuesday. West
to northwest wind decreasing to near 10 knots tonight and Tuesday
morning. MVFR due to stratus redevelops by mid Tuesday evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus and fog /LIFR-IFR/ tonight and
Tuesday morning, with clearing back to near the coastline Tuesday
afternoon. Onshore winds 5 to 15 knots.

&&

.MARINE...
(Tonight through next Sunday)
Issued at 933 PM PDT Mon Jun 23 2025

Moderate to fresh northwesterly breezes, with occasional strong
gusts, will prevail through the week. Seas will be moderate though
Wednesday and build to rough by the end of the week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 1 AM PDT Tuesday for CAZ006-506-508.

PZ...Small Craft Advisory until 3 AM PDT Tuesday for Pt Arena to Pt
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory from 3 PM Tuesday to 3 AM PDT Wednesday for
     Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...RW
LONG TERM....RW
AVIATION...Canepa
MARINE...Canepa

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