716
FXUS66 KMTR 250507
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
907 PM PST Fri Jan 24 2025

...New SYNOPSIS, UPDATE...

.SYNOPSIS...
Issued at 847 PM PST Fri Jan 24 2025

Cool temperatures will persist through the extended forecast
along with chances for light rain and gusty winds this weekend.

&&

.UPDATE...
Issued at 847 PM PST Fri Jan 24 2025

Forecast remains on track this evening for increasing chances of
light rain beginning early Saturday morning over the southern
Central Coast, eventually expanding in coverage across the rest
of our area through the day tomorrow. This will not be a
widespread wetting rain, with most locations fortunate to receive
some precipitation seeing less than a tenth of an inch. Elevated
coastal areas from Santa Cruz south through the Santa Lucias may
see up to a half- inch of rain over the next couple of days, and
portions of the Santa Lucias above 4000ft may get some
accumulating snow as showers move onshore. Chances for
thunderstorms remain low, with late Sunday morning into Sunday
afternoon looking like the best window for embedded thunderstorms
possibly moving onshore across far southern Monterey County.

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 1259 PM PST Fri Jan 24 2025

Afternoon temperatures will be warmest today across the Central
Coast as temperatures across the interior approach 70 degrees.
Meanwhile, cooler temperatures are expected across the Bay Area and
points northward with highs in the low-to-mid 60s. Otherwise,
coastal clouds remain over the ocean while high clouds stream inland
ahead of an approaching frontal system.

Tonight into early Saturday morning is when winds will increase
across the Interior North Bay Mountains with a Wind Advisory in
effect from 10 PM this evening through 10 AM Sunday. This is due to
winds expected to be out of the north/northeast at 15-25 mph and
gusts up to 50 mph (locally stronger in the highest peaks). Also,
tonight we have a Frost Advisory in effect for the North Bay Valleys
and interior portions of the East Bay (including the hills),
southern Salinas Valley, and the higher terrain in San Bentio
County. All of this is in response to the cold front expected to
move across the region overnight and into Saturday afternoon.

Tomorrow, temperatures will struggle to warm into the upper 50s in
wake of the cold front. In the higher elevations, look for
temperatures only to warm into the upper 30s to mid 40s. Light rain
will also be possible, starting in the morning across the Central
Coast in the form of drizzle and transitioning to light rain in the
afternoon and evening. Light snowfall is possible across the highest
peaks of the Central Coast, espeincreasingcially in the Santa
Lucia Range.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 1259 PM PST Fri Jan 24 2025

Sunday, off and on showers (snow showers in the highest terrain)
will persist over the Central Coast, with little to no rainfall
across the North Bay. Rainfall amounts are forecast to be generally
light through the weekend amounting to 0.10" to 0.33" in the major
populated areas of the Central Coast to 0.33" to 0.50" in the Santa
Cruz Mountains, Santa Lucia Range and the higher terrain of Monterey
and San Benitio counties. The South Bay and the San Francisco Bay
Area look to pick up a trace to a few hundredths of an inch.

From previous forecaster: "Dry weather should return Monday and
stick around through at least the mid-week as ridging returns to the
region. Highs during this period will hover in the middle 50s to the
lower 60s across the lower elevations, near or slightly below the
seasonal averages. Lows from Monday through Wednesday morning drop
to the lower to middle 30s in the inland valleys, around 5 to 10
degrees below seasonal averages, and even near the coast lows hover
around 40, resulting in a strandincreasing of chilly temperatures
across the region. The NBM is starting to pick up on a chance for
rain to return towards the latter part of next week, but rainfall
amounts and timing depend on the prognosis of an incoming trough
and how quickly it erodes the ridging. CPC outlooks show a signal
for rainfall totals near or slightly above seasonal averages for
the first week of February."

&&

.AVIATION...
(00Z TAFS)
Issued at 432 PM PST Fri Jan 24 2025

Currently VFR with broken to scattered high clouds moving across the
region. Scattered precipitation is expected across the Central Coast
and portions of the Bay Area starting early tomorrow morning.
Ceilings will gradually return and lower overnight with the most
likely scenario being the development of MVFR CIGs. Patchy fog is
possible across the North Bay after 12-14Z when cloud cover is
expected to clear. Confidence remains low at this time given fog
development looks fairly patchy in the ensembles. Showers are
expected to remain fairly light with minimal impacts to airport
operations expected. Winds generally remain light to moderate
through the TAF period but start to pick up for most sites by mid
tomorrow morning.

Vicinity of SFO...VFR through the TAF period. Low confidence but
light rain may move into the vicinity of SFO mid tomorrow morning
into the afternoon hours. Forecast totals only amount to a few
hundredths of an inch with no major impacts to SFO expected. CIGs
will decrease early tomorrow morning but are expected to stay within
the VFR category. Wind direction will fluctuate throughout the TAF
period with winds initially onshore and becoming more offshore
by tomorrow.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals...Bumped up the arrival of stratus across the
Central Coast to 04/05Z given ensemble and LAMP guidance. Scattered
light showers become more likely at MRY and SNS late tomorrow
morning with accumulations of a few tenths of an inch expected. MVFR
conditions will gradually lift to VFR by late tomorrow morning but
CIGs will linger through the TAF period. Onshore flow gradually
becomes offshore tonight before more moderate, SW winds develop mid
to late morning as rain chances increase.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 432 PM PST Fri Jan 24 2025

A cold low pressure system arriving from the north Saturday will
result in increasing northerly winds over the coastal waters
tonight and Saturday. The strongest winds will be north of Point
Reyes over the outer waters. Expect rough to very rough seas
tonight through Sunday before wave heights begin to abate and
winds weaken  Monday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 10 AM PST Sunday for CAZ504.

     Freeze Watch from late Saturday night through Tuesday morning
     for CAZ504-506-508-510-512>518-528>530.

     Frost Advisory from 1 AM to 9 AM PST Saturday for CAZ506-510-
     514>516-518.

PZ...Small Craft Advisory until 9 AM PST Saturday for Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory until 9 AM PST Saturday for Pigeon Pt to Pt
     Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt
     Reyes to Pigeon Pt 0-10 nm.

     Gale Warning until 3 PM PST Saturday for Pt Arena to Pt Reyes 10-
     60 NM.

     Small Craft Advisory until 3 PM PST Saturday for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

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

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