103
FXUS66 KMTR 072132
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
232 PM PDT Mon Apr 7 2025

...New MARINE...

.SYNOPSIS...
Issued at 1238 PM PDT Mon Apr 7 2025

Cooler temperatures today will give way to a resumed warming trend
for the rest of the work week. Slight cooling and gustier winds are
expected this weekend.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 1238 PM PDT Mon Apr 7 2025

The weak cold front which brought generally light rain across the
region last night into this morning is moving off to the south, with
a second weak front coming into the North Coast helping to reinforce
the cloudier and slightly cooler conditions for the rest of the day.
Light drizzle is possible for the rest of the day, especially in the
higher elevations, but no additional accumulation is expected. High
temperatures across the Bay Area reach the middle 60s to near 70
inland, the lower to middle 60s on the Bayshore, and the middle to
upper 50s along the Pacific coast. Temperatures are somewhat warmer
in the Central Coast, where the cold frontal influence was not as
strong, where temperatures range from the middle to upper 60s in the
Monterey Bay region and Big Sur, to the middle and upper 70s in the
valleys of southern Monterey County, where you`d be forgiven for
asking, "what cold front?". Low temperatures will fall into the
middle 40s to lower 50s for most of the region, with upper 30s to
lower 40s expected in the higher elevations.

The warming trend that characterized the end of last week will
resume tomorrow, as the upper level ridge rebuilds over the western
United States. Temperatures in the Central Coast and the coastal Bay
Area won`t warm that much, at most a couple of degrees in Santa Cruz
County, but the inland valleys of the Bay Area will warm into the
upper 60s and the lower 70s.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 1238 PM PDT Mon Apr 7 2025

The peak of the warming trend is expected on Wednesday and Thursday
with a pronounced ridge over the western United States. Highs in the
inland valleys will rise into the upper 70s to lower 80s, or around
5 to 10 degrees above the seasonal average, while the southern
Salinas Valley will see highs in the middle to upper 80s. Along the
coast, there is some uncertainty regarding the high temperature
forecast, with the reasonable range of highs in downtown San
Francisco ranging from the upper 60s to the middle 70s. A lot of the
coastal temperature forecast rides on four words: marine layer sea
breeze. The marine layer tends to act as a moderating influence on
coastal temperatures, both in terms of bringing in cooler air from
the Pacific Ocean and also enabling the sea breeze which will
enhance the cooling effect on the human body. Forecasting the extent
of the marine layer influence is difficult beyond the next couple of
days, but some of the first high-resolution model data that has come
in suggests that the marine layer will be pretty shallow, up to
around 500 feet at most, which would limit the influence to pretty
much the immediate Pacific coast. For now, we`ve bumped coastal high
temperatures up a few degrees due to the uncertainty surrounding the
marine layer resulting in high temperatures in the 60s and lower
70s, but don`t be surprised if temperatures rise a few degrees above
the current forecast if the marine layer doesn`t develop as
expected, or fall a few degrees short if it overproduces.

A slight cooling begins on Friday into the weekend as a positively
tilted upper level trough approaches the West Coast. Most of the
moisture from the trough will be expended over the Pacific Northwest
and far northern California, leaving the Bay Area and Central Coast
dry. The main sensible weather impacts will be somewhat cooler
highs, with temperatures dropping to the lower 70s in the inland
valleys, the middle to upper 60s near the Bays, and the upper 50s
along the Pacific coast, as well as some gusty winds across the
region. The current forecast does not call for gusts to reach Wind
Advisory criteria, with the strongest gusts around 30 miles per hour
along the ridgelines, at the coast, and through gaps and passes.

Longer term CPC outlooks suggest that temperatures lean above
seasonal averages and precipitation totals lean below seasonal
averages into the third week of April.

&&

.AVIATION...
(18Z TAFS)
Issued at 1108 AM PDT Mon Apr 7 2025

Lingering MVFR to localized IFR, around KHAF, can be found across
the Bay Area and Central Coast this morning. There should be some
improvement by mid to late afternoon at most sites, with lowering
cigs returning late this evening or overnight for most terminals.
Continued to trend MVFR at most sites with the possibility of IFR
for coastal terminals.

Vicinity of SFO...Watching satellite and nearby webcams this
morning, and it showed MVFR cigs around KSFO with some clearing
beginning to occur. Latest obs show VFR at the site, which occurred
near the top of the hour and will hopefully hold and not invade the
terminal. Nearby webcams still show MVFR cig hovering the vicnity
but expect to see continued improvement over the next couple of
hours. VFR is then expected through the evening with MVFR cigs
returning sometime around 9Z and then likely holding through much of
the morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Low clouds hug the southern portion of the
Monterey Bay area, with MVFR cigs being reported. Guidance shows
these lingering through mid to late afternoon which was trended
towards in the latest update. A brief period of VFR conditions
should occur during the evening and early overnight hours before
MVFR conditions return.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 232 PM PDT Mon Apr 7 2025

Moderate height, long period swell from the WNW will continue
across the coastal waters. A secondary front will continue to pass
over the waters this afternoon, shifting winds from the SW to the
NNW and N by Tuesday morning. Winds will remain gentle to moderate
during this period for much of the waters, with fresh N winds
expected late Tue for the Point Pinos to Point Piedras forecast
areas. The long period swell will gradually abate through mid-
week before stronger NW winds arrive this coming weekend.

&&

.BEACHES...
Issued at 418 AM PDT Mon Apr 7 2025

A Beach Hazard Statement remains in effect for the entire
coastline. Sneaker waves will be the main threat before switching
to larger shore break and rip currents. Beachgoers should be
mindful today given potential hazards. Beachgoers should stay off
of jetties and rocks, keep pets on a leash, wear a life jacket,
and never turn your back on the ocean!

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 11 PM PDT this evening for CAZ006-
     505-509-529-530.

PZ...Small Craft Advisory from 3 PM to 9 PM PDT Tuesday for Pt Pinos
     to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 AM PDT Tuesday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...KR
MARINE...KR

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