FXUS66 KMTR 132351
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
451 PM PDT Mon Apr 13 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1125 AM PDT Mon Apr 13 2026

 - Slightly cooler to near normal temperatures through Thursday

 - Periods of gusty winds, especially at higher elevations 
   Wednesday through Friday

 - Warmer temperatures return Friday and Saturday before unsettled
   weather returns for early next week

&&

.SHORT TERM...
Issued at 1125 AM PDT Mon Apr 13 2026
(This afternoon through Tuesday)

Lingering rain showers persist over the Pacific late this morning 
with these forecast to diminish through the afternoon and evening. 
The RRFS (rapid refresh forecast system) and other CAMs (convection-
allowing models) indicate the potential for isolated rain showers 
across the higher terrain of the southern Diablo Range and Santa 
Lucia Range this afternoon, diminishing as the sunsets. Otherwise, 
mostly dry conditions return to the region this afternoon with 
afternoon temperatures forecast to be in the upper 50s to low 60s 
near the coast and low-to-upper 60s across the interior. However, 
the highest peaks may not reach much above the upper 40s to low 50s. 

Tonight, temperatures will be chilly across the interior North Bay 
Valleys and interior Central Coast with mid-to-upper 30s expected. 
There is a low end potential for frost, yet widespread coverage in 
not currently anticipated. Elsewhere, temperatures will range from 
the low 40s to near 50 degrees F (warmest near the coast). 

For Tuesday, expecting dry conditions with temperatures warming 
regionwide by a few degrees as a shortwave ridge builds in wake of 
the exiting trough. 

&&

.LONG TERM...
Issued at 1125 AM PDT Mon Apr 13 2026
(Tuesday night through next Sunday)

Additional warming is expected on Wednesday, but only again by a few 
degrees. All of this is ahead of an approaching frontal boundary 
that is forecast to be mostly dry. However, there are chances across 
far northern Napa and Sonoma counties Wednesday afternoon and 
evening, generally less than 25%. This said, there very well may be 
light precipitation as far south as the Central Coast as the front 
moves across the region late Wednesday evening and into early 
Thursday morning. Little to no measurable rainfall expected with 
this system.

In wake of this system, offshore winds are forecast to be strongest 
across the North Bay Mountains and East Bay hills Thursday and into 
Friday. This will be as the exiting system shifts into the Great 
Basin and/or Intermountain West. There still is some uncertainty 
with the exact track of this system, thus less confidence in the 
strength of offshore winds. However, widespread wetting rainfall 
across the region has greatly reduced fire weather concerns (at 
least in the short term).   

Weak ridging will build in behind the aforementioned system on 
Friday and Saturday with temperatures returning to near seasonal 
averages along with dry weather. Unsettled weather looks to return 
late Saturday and into early next week as another mid/upper level 
trough drops out of the Gulf of Alaska and approaches the West 
Coast. 

&&

.AVIATION...
(00Z TAFS)
Issued at 444 PM PDT Mon Apr 13 2026

Fair weather cumulus continue to linger across the Bay Area,
although the coverage is gradually decreasing as the sun angle
starts to increase. There is a chance for MVFR ceilings across all
terminals overnight, but the probability varies depending on
location. Otherwise winds will remain onshore while gradually
decreasing to a gentle breeze overnight.

Vicinity of SFO...Strong onshore winds will gradually ease through
the evening hours. The biggest question is if SFO will get a
ceiling overnight. GFSLAMP guidance shows a 20-30% chance of MVFR
ceilings between 12Z and 16Z. Even if ceilings do form Tuesday
morning, there is enough instability to virtually eliminate the 
risk of anything lower than MVFR conditions. More likely any
cloud bases will be in the VFR range.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...The best chances for ceiling impacts are
at MRY and SNS overnight. With a reforming deep marine layer,
there is very little chance for anything lower than 1,500 feet
however. 

&&

.MARINE...
(Tonight through next Saturday)
Issued at 444 PM PDT Mon Apr 13 2026

Rain showers linger through the morning before diminishing into
the afternoon. Winds stay light through early afternoon,
increasing to a moderate to fresh northwesterly breeze through
Wednesday. Winds build again on Thursday leading to near gale
force gusts into the end of the work week. Moderate seas continue
through Wednesday before rough seas arrive on Thursday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Wednesday for Pt Arena to Pt 
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory until 3 AM PDT Tuesday for Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pt Pinos to 
     Pt Piedras Blancas 0-10 nm.

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

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Flynn
MARINE...RGass

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Prepared by Boulder-Creek.com Weather at: Mon Apr 13 18:30:03 PDT 2026