Mount Hermon, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

051
FXUS66 KMTR 211204
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
504 AM PDT Sat Jun 21 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 400 AM PDT Sat Jun 21 2025

Elevated fire weather concerns continue through Sunday morning.
Otherwise quiet weather on tap after that with near normal
temperatures.

&&

.SHORT TERM...
(Today and tonight)
Issued at 400 AM PDT Sat Jun 21 2025

The forecast remains on track with an upper level low tracking into
the Great Basin, deepening the larger upper level trough. Flow
will remain onshore with gusty winds picking back up by mid to
late morning. The pressure gradient looks to support another gusty
day with gusts peaking 25-35 mph, with gusts up to 40 mph, or
locally higher. for areas along the coast or at wind prone gaps
and passes. The forecast looks to remain dry, especially for areas
above the marine layer where recovery is expected to be poor. The
marine layer should be around 1500-2000ft. Given these conditions
and cured grasses and dried shrubbery, elevated fire weather
countdowns will continue.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 400 AM PDT Sat Jun 21 2025

Saturday evening into Sunday morning, winds look to remain breezy
before beginning to ease. Upper level troughing looks hold, though a
perturbation forms causing the through to deepen a bit more over
Central CA. This then looks to essentially park itself over CA and
NV through midweek with more zonal flow returning mid to late week.
Weather should generally be more typical for this time of year,
seasonable temperatures, nighttime and morning stratus, and
generally quiet weather.

&&

.AVIATION...
(12Z TAFS)
Issued at 503 AM PDT Sat Jun 21 2025

Currently VFR at the terminals with very patchy stratus. High
confidence in VFR through the TAF period. Strong and gusty onshore
winds are expected through the TAF period with the help of the
passage of an upper-level shortwave trough.

Vicinity of SFO...Currently VFR with westerly flow. High confidence
in VFR through the TAF period. Westerly/westnorthwesterly winds will
strengthen through the morning with gusts up to 35 knots to be
expected in the afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with southwesterly flow at
MRY and VFR with westerly flow at SNS. High confidence in VFR
through the TAF period, although there is some IFR stratus within
the vicinity of the terminals. Gusty onshore winds will prevail
through the TAF period.

&&

.MARINE...
(Today through Thursday)
Issued at 503 AM PDT Sat Jun 21 2025

Widespread hazardous marine conditions are expected over the
waters through the weekend in the form of near-gale northerly
breezes, severe gale force gusts, and rough to very rough seas.
The bays will be more sheltered, but will still experience fresh
to strong northwesterly breezes.

&&

.FIRE WEATHER...
Issued at 323 AM PDT Fri Jun 20 2025

Elevated fire weather conditions continue today across the
interior becoming more widespread on Saturday, with RH values
around 30% expected across the interior of the East Bay south
through the Gabilan Range, along with the Santa Lucia mountains
this afternoon. Gusty winds above the marine layer and elevated
interior locations will once again be around 25 to 40 mph with
less coverage today than Thursday. Brief periods of critical fire
weather conditions are possible with daytime relative humidities
of 15 to 25% in the interior. However, continuing marine layer
influence, especially during the night, and the fact that winds
remain onshore, mean that widespread critical fire conditions do
not develop across the district. Gusty winds begin to subside
somewhat on Saturday, but the upper level pattern will lead to
more northerly winds developing across the region. As with
Thursday`s fire weather threat, widespread critical fire weather
conditions are not expected within the district, although the fire
weather threat will increase once again for areas closer to the
Central Valley. The fire weather threat will continue to diminish
Sunday into the early part of next week with the gusty winds
further relaxing, although humidity values in the interior will be
slow to rise.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Mry Bay-SF Bay N
     of Bay Bridge.

     Gale Warning until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-
     60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 AM PDT this morning for Pigeon Pt
     to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning from 9 AM this morning to 3 AM PDT Sunday for
     Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Sarment
MARINE...Sarment

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