Technical NOAA Weather Discussion

FXUS66 KMTR 041848
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1148 AM PDT Thu Jun 4 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1255 AM PDT Thu Jun 4 2026

 - Breezy to gusty onshore winds mainly in the afternoon and
   evening

 - Notable cool down for the weekend through the middle of next 
   week

&&

.UPDATE...
Issued at 842 AM PDT Thu Jun 4 2026

Visible satellite this morning shows a tale of two stories...sunshine
or clouds. If you're north of the Golden Gate you have clear 
skies and south a marine layer stratus push. It's also interesting
to see stratus push inland across the complex terrain of the
Central Coast. This morning clearly demonstrates that every 
little nook and cranny of the Salinas Valley was getting a taste
of clouds - the atmosphere is a fluid and the stratus is a liquid
getting "poured" into a topographic mold. 

What's in store for the rest of the day? Already seeing clearing
across the Santa Clara Valley. Salinas Valley will follow with 
sun by late morning. Mild along the coast, but if you want a taste
of summer head way inland with highs in the 80 to mid 90s. Beach 
weather? Kinda, some sun, but do expect the winds to crank up this
afternoon. Interior locations will be breezy too, but not as 
windy as yesterday.

No update needed at this time.

MM

&&

.SHORT TERM...
Issued at 1255 AM PDT Thu Jun 4 2026
(Today and tonight)

Strong mid to upper level high pressure i.e. 500 mb height 589 
decameters and moderate northerly 6.7 mb ACV-SFO and onshore 3.4 
mb SFO-SAC surface pressure gradients prevail early this morning. 
The marine layer depth varies from 1000 feet to locally 2000 feet.
The surface pressure gradients and cool air advection are producing
gusty wind flow trapped beneath the upper level high's lower level
temperature inversion with a varying focus of onshore winds through
the coastal gaps.

With early June solar input and the close proximity of the lower 
level temperature inversion with the strong mid to upper level 
high pressure system, daytime high temperatures will warm back up 
above normal today. Forecast highs today upper 60s to lower 70s 
coastside to the 80s and 90s far inland.

&&

.LONG TERM...
Issued at 1255 AM PDT Thu Jun 4 2026
(Friday through Wednesday)

With strong mid to upper level high pressure prevailing Friday,
daytime highs will warm back up to above normal with warmest to
hottest inland temperatures reaching the 80s and 90s. On Saturday
the upper level high will begin to weaken, daytime highs will
begin to trend lower with inland highs mainly in the 70s and 80s.
Sunday's temperatures will be a repeat of Saturday's temperatures.

Additional cooling Monday through Wednesday will lower daytime high
temperatures a few more degrees with 70s well inland except in the
80s southern interior. Recent GFS and to some extent the ECMWF have
been showing a trough arriving with some measurable rainfall early
next week. With a strong late season meridional temperature gradient,
ongoing negative (cool) phase Pacific Decadal Oscillation and moisture
tap back to the western Pacific, it'll be interesting to see if e.g.
the recently wetter solution GFS verifies. 

&&

.AVIATION...
(18Z TAFS)
Issued at 1147 AM PDT Thu Jun 4 2026

Widespread VFR conditions as the last bit of stratus clears from the 
coastline. Clear skies and gentle to moderate breezes (generally 
from the west but locally driven) dominate the TAF period, with a 
couple of sites experiencing strong gusts in excess of 20kts. 
Coastal sites will see another round of stratus coverage tonight 
with IFR-MVFR ceilings. Currently, there is low confidence on how 
widespread stratus will be at HAF so, decided to leave it as FEW-
SCT015 beginning tonight ~10pm PDT. The low to mid level airmass off 
the coast remains dry with satellite currently showing a wide gap in 
cloud coverage to the west.

Vicinity of SFO...VFR through the TAF period. Westerly winds pick up 
to moderate strength by the early afternoon. Gusts in excess of 
20kts will also begin by then and persist until ~9pm PDT. Winds 
diminish to gentle breezes overnight into Friday morning, though 
they are expected to increase again to moderate strength by early 
Friday afternoon.

SFO Bridge Approach...NW to W moderate winds with strong gusts 
similar to that of SFO prevail into the evening. Winds diminish to a 
light breeze (~6kts) a bit earlier than SFO and become variable 
overnight. Aligns with SFO again by late Friday morning.

Monterey Bay Terminals...VFR through the afternoon until the stratus 
deck returns again this evening. The marine layer will become ~1000 
feet deep overnight which will bring borderline IFR-LIFR ceilings at 
MRY around 9pm PDT and IFR ceilings at SNS around midnight. MVFR 
ceilings are expected by Friday morning at both terminals as the 
marine layer begins to erode. Onshore gentle breezes will prevail 
through the TAF period.

&&

.MARINE...
(Today through Tuesday)
Issued at 444 AM PDT Thu Jun 4 2026

Hazardous conditions for small craft continue through the weekend.
Gale force gusts are expected across the outer waters and along
the coastal jet regions. Moderate to rough seas will continue to
build through tomorrow to become rough to very rough for the inner
and outer waters. Conditions will slowly begin to improve Monday
as northwesterly winds diminish to become fresh to strong and
seas abate to become moderate.

&&

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

     Gale Warning until 9 AM PDT Friday for Pigeon Pt to Pt Pinos 10-
     60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-
     60 NM.

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

     Small Craft Advisory until 9 AM PDT Friday for Pt Pinos to Pt 
     Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Navarrete
MARINE...Sarment

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Prepared by Boulder-Creek.com Weather at: Thu Jun 4 12:30:02 PDT 2026
From the National Weather Service