FXUS66 KMTR 041145
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
445 AM PDT Thu Jun 4 2026
...New AVIATION, MARINE...
.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
&&
.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...
(12Z TAFS)
Issued at 444 AM PDT Thu Jun 4 2026
Currently a mixed bag of LIFR-VFR with a dry cold draped across the
Bay Area. Stratus has been effectively wiped out in its wake with
terminals south of the Golden Gate being impacted by LIFR-IFR
ceilings. Widespread VFR is expected by the afternoon. Moderate
confidence on IFR ceilings returning to coastal terminals tonight.
Low confidence elsewhere due to the drier airmass and mixed
atmosphere that is expected. Diurnal winds will prevail.
Vicinity of SFO...Currently IFR with westerly flow. High confidence
in VFR by late-morning in the 16Z-18Z timeframe. Westerly winds will
increase through the day with gusts of 30 knots likely this
afternoon and evening. Low confidence in a ceiling returning tonight.
SFO Bridge Approach...Patchy stratus is expanding across the San
Mateo Bridge Approach and will likely clear later than the terminal.
Monterey Bay Terminals...Currently LIFR with southwesterly flow at
MRY and LIFR with westerly flow at SNS. High confidence in VFR
prevailing by this afternoon. Moderate (60%) confidence on IFR
ceilings returning this evening.
&&
.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 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.
Small Craft Advisory until 9 AM PDT this morning for Pigeon Pt
to Pt Pinos 10-60 NM.
Gale Warning from 9 AM this morning to 9 AM PDT Friday for
Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Sarment
MARINE...Sarment
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Prepared by Boulder-Creek.com Weather at: Thu Jun 4 06:30:02 PDT 2026
From the National Weather Service
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