FXUS66 KMTR 241150
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
450 AM PDT Fri Apr 24 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1205 AM PDT Fri Apr 24 2026
- Low potential for drizzle this morning across the Central Coast
- Additional rounds of drizzle/light rain likely Saturday and
Sunday
- Below normal temperatures this weekend before a warming trend
kicks off early next week
&&
.SHORT TERM...
Issued at 1205 AM PDT Fri Apr 24 2026
(Today and tonight)
High clouds are streaming in with some lower level stratus making
its way along the coast. There is some potential for fog tonight
across the North Bay Valleys but confidence is mixed given the high
level clouds moving in. Any fog that does develop should be
relatively patchy due to the high level clouds minimizing how much
radiational cooling is able to occur. If you do encounter fog on
your morning commute remember to slow down, turn on your low beam
headlights, and allow extra time to reach your destination.
Broad upper level troughing persists across California as a deep
upper level low remains fairly stationary over Canada/Montana/North
Dakota. Within this broader trough, a weak upper level low looks to
develop offshore of the Bay Area and move inland throughout the day.
In terms of our rain chances, the current forecast grids show a less
than 10% chance of precipitation today, but, some CAMs are showing
isolated showers developing across the region Friday morning. The
question then becomes how much moisture will actually be available
today. The GFS shows a brief uptick in PWAT values from around 0.45"
up to 0.55-0.65" Friday morning. The timing of this slight moisture
flux matches well with when models like the NAM show some scattered
showers over the Santa Lucia Range and the potential for drizzle
across the rest of the Central Coast. Drier conditions are expected
across the rest of the Bay Area so not anticipating drizzle to
extend beyond coastal areas. If any rain is able to develop it is
still unlikely for accumulations to be greater than a few hundredths
to (maybe) a tenth of an inch across the Santa Lucia Range. Heading
into the afternoon, we may start to see more radar returns across
the marine environment but at this time we are not anticipating
these showers moving inland or any accumulation from them. High
temperatures on Friday will cool by around 4-5 degrees with highs
dropping into the mid to upper 60s across the interior, 50s to 60s
along the coast, and mid to upper 70s across the interior Central
Coast. Diurnally breezy onshore winds continue with windiest
conditions expected across the Salinas Valley and Altamont Pass
region.
&&
.LONG TERM...
Issued at 1205 AM PDT Fri Apr 24 2026
(Saturday through Thursday)
Heading into Saturday, we see slightly higher chances for
precipitation as the upper level trough over California becomes more
well defined and a second weak upper level low pushes into Southern
California. This system will be accompanied by a stronger PWAT plume
but the bulk of this moisture is aimed to our south. Model guidance
does show several pulses of moisture moving through our CWA Saturday
and Sunday which may support additional rounds of drizzle to light
rain this weekend. Widespread drizzle is the most likely outcome
with light rain possible in the Santa Lucia Range thanks to
orographic uplift. Similar to Friday, precipitation totals will be
minimal, ranging from a trace to a few hundredths of an inch.
Portions of the higher terrain could see up to a tenth of an inch of
rain between Saturday and Sunday. No major wind concerns with this
system but locally gustier winds between 25 to 35 mph are expected
across the higher elevations on Saturday. Broad upper level
troughing continues through the remainder of the long term before
upper level ridging looks to briefly rebuild Friday into early next
weekend.
Temperatures remain below normal this weekend with highs in the
upper 50s to 60s. This is short lived with a slight warming trend
kicking off Monday. Interior high temperatures will warm into the
upper 60s to low 70s on Monday before warming into the low to mid
70s Tuesday through Thursday. Coastal high temperatures will remain
relatively stable in the 50s to 60s through late next week. In the
long run, CPC guidance shows a return leaning above normal
temperatures and leaning above normal precipitation for the end of
April into the beginning of May. Ensemble guidance has been showing
the potential for another round of light, beneficial rain in this
timeframe. This will be something to keep an eye on as we exit
our rainy season and head into summer.
&&
.AVIATION...
(12Z TAFS)
Issued at 441 AM PDT Fri Apr 24 2026
A mix of MVFR/VFR cigs early this morning with all terminals
expected to be VFR by late morning, and should persist into the
evening hours. By later this evening a steadier fetch of onshore
flow will replace relatively light mixed surface flow along the
coastline. Expect more widespread MVFR cigs from late tonight
through Saturday morning.
Vicinity of SFO...A mix of MVFR/VFR cigs with steadier but
relatively light onshore flow developing. Moderate confidence in
MVFR cig heights with guidance indicating a low chance for IFR
cigs through the TAF period.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR cigs will give way to VFR by late
morning/early afternoon when breezy onshore flow develops for the
afternoon and early evening. Expect MVFR cigs for KMRY later
this evening, with lower confidence that the relatively weak
onshore flow will penetrate into the Salinas Valley.
&&
.MARINE...
(Today through Wednesday)
Issued at 441 AM PDT Fri Apr 24 2026
Choppy seas will begin to gradually subside today and continue to
do so into the weekend. There is a chance for light rain this
morning over the southern outer waters, along with drizzle and
light rain along the coast this weekend.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Fri Apr 24 08:30:03 PDT 2026
From the National Weather Service
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