665
FXUS66 KMTR 051023
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
323 AM PDT Sat Jul 5 2025

...New SHORT TERM, LONG TERM, MARINE...

.KEY MESSAGES...
Updated at 320 AM PDT Sat Jul 5 2025

 - Temperatures remain below seasonal averages into early next
   week.

 - Gradual pattern change bringing warming trend for second half
   of next week begins Wednesday.

 - Marine layer increases and expands farther inland for end of
   the weekend, beginning of next week.

&&

.SHORT TERM...
Issued at 320 AM PDT Sat Jul 5 2025
(Today and tonight)

A weak upper level disturbance has begun to split off from the
northern jet across the Pacific Northwest and will gradually develop
into a cut-off low later tonight, and settle off the Central Coast
by early Sunday morning. Dry air just above the marine layer
continues to make the coastal stratus cloud cover forecast
difficult. A sliver of low stratus can be seen at this hour (3AM
PDT) building south from the Bay Area toward the San Lucia coastal
range, bypassing the Monterey Bay at the moment. Expect stratus to
remain mostly confined to coastal locations where it does develop
with little inland intrusion. Todays temperatures will continue to
be on the cool side with bright sunshine inland and slacking wind
compared to previous couple days.

&&

.LONG TERM...
Issued at 320 AM PDT Sat Jul 5 2025
(Sunday through Friday)

A cut off upper level low will stall off the California Central
Coast over the next few days. As the weak upper system slowly
meanders offshore we should see an improved fetch of moisture above
the marine layer up to approx 500mb, resulting in an expanding
marine layer that will penetrate farther inland as we head into the
beginning of next week. Early morning drizzle and fog may also be
more widespread for the beginning of next week. By Wednesday the
stalled upper low begins to make progress inland. Considerable
uncertainty remains in the forecast for a potential warm up late
next week, however expect temperatures by the end of next week into
next weekend to at least rebound closer to normal, with eyes on some
potential moderate heat risk if the synoptic pattern supports longer
residence time of ridging aloft over our region late in the extended
forecast.

&&

.AVIATION...
(06Z TAFS)
Issued at 945 PM PDT Fri Jul 4 2025

It`s VFR-MVFR, satellite and surface observations show a few
patches of stratus redeveloping in the Bay Area. The SFO-SAC and
ACV-SFO pressure gradients are approx 3 mb each this evening. The
marine layer depth i.e. from sea level to lower level temperature
inversion varies from 1200 to 1800 feet over the Bay Area, to a
somewhat more compressed 1000 feet depth at the Point Sur profiler
(where thermal ridging aloft is stronger). Stratus and fog /IFR-LIFR/
will continue to develop tonight and Saturday morning under nocturnal
radiative cooling to space. Stratus and fog /LIFR-IFR/ will mix out
to the coastline Saturday otherwise VFR is forecast. Onshore winds
prevail during the 06z TAF cycle.

Vicinity of SFO...VFR. West wind easing overnight and Saturday
morning. West wind increasing to 17 gusts to 25 knots Saturday
afternoon and early evening. Forecast models are struggling with
the areal coverage of stratus; for now, it`s a low confidence
stratus ceiling /IFR/ forecast in the 06z TAF for Saturday evening
and night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...With nocturnal radiative cooling and more
focused lower level cool air advection here tonight and Saturday
morning, this supports redevelopment of stratus and fog /IFR-LIFR/,
timing is mainly after midnight to Saturday morning. Then diurnal
mixing will lift IFR-LIFR to MVFR-VFR by late Saturday morning and
early afternoon. Mainly onshore winds 5 to 15 knots.

&&

.MARINE...
(Today through Thursday)
Issued at 320 AM PDT Sat Jul 5 2025

Moderate seas and a fresh to strong northwesterly breeze will
continue into the weekend. Winds will diminish late Sunday into
Monday with a moderate breeze to continue through late next week.
Occasional gale force gusts are possible along the Big Sur
coastline  Saturday afternoon. Winds increase and significant wave
heights build beginning late next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for SF Bay N of Bay Bridge.

     Small Craft Advisory from 9 AM this morning to 9 PM PDT this
     evening for Mry Bay.

     Small Craft Advisory until 9 AM PDT Sunday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 AM PDT this morning for Pt Reyes to
     Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 3 AM PDT Sunday
     for Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 PM PDT Sunday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Canepa
MARINE...Kennedy

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