Alviso, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

988
FXUS66 KMTR 220005
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
505 PM PDT Sat Jun 21 2025

...New AVIATION...

.SYNOPSIS...
Issued at 219 PM PDT Sat Jun 21 2025

Fire concerns linger for today and tonight, but ease as winds
reduce into Sunday. Expect a modest warming trend for the more
inland areas into the next work week along with a return of
coastal clouds and fog.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 219 PM PDT Sat Jun 21 2025

Winds are building into the afternoon. However, the updated forecast
is showing that the widespread wides are going to be weaker overall
than the winds experienced yesterday, with only a few exceptions
along the immediate coast. Temperatures are mostly around average
today as the onshore flow continues and today looks to be the
coolest of the next seven. Winds over land reduce into the evening
and early tonight, but will stay gusty within the marine
environment.

The reduction of winds tonight marks the end of our breezy to gusty
pattern and pulls the interior areas out of near critical fire
danger. However, a lot of the finer fire fuels (grasses and small
plants) have dried and cured in the last few days of dry, sunny and
windy conditions, so we urge folks to stay fire weather aware.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 219 PM PDT Sat Jun 21 2025

Winds have been the big focus of the forecast over the last few
days, but as the upper level pattern changes, the breezy and gusty
conditions are mostly going to be focused over the marine
environment into the next work week.

Said change in the upper level pattern with feature the upper level
pushing east and slightly south. This will reduce onshore flow into
the mid week and weaken winds across the region. Temperatures will
increase in the far interior, while the coast and slightly inland
areas stay mostly unchanged as marine stratus and fog begin to
reestablish in the calmer conditions. As of the current forecast,
Thursday looks to be the warmest day of the forecast as the more
interior valleys settle into the 90s and some of the warmest of the
warm hitting the 100 degree mark, but this won`t be widespread and
the coastal and slightly inland areas remain in the 60s and 70s.

Something to note, the mid-week model agreement is fair with the
current official forecast, but some models hint at the trough pushing
farther south and propagate in such a way that could introduce more
offshore flow. This will still result in the midweek warm up, but
the drier flow could limit the marine layer and coastal cloud cover,
making for a much warmer days for the coast. The forecasting team
will be keeping an eye on how this continues to develop over the
next few forecast updates, be sure to keep checking back in!

&&

.AVIATION...
(00Z TAFS)
Issued at 505 PM PDT Sat Jun 21 2025

VFR through the TAF period. Low confidence that IFR to MVFR CIGs
will develop at HAF and MRY overnight. LAMP guidance is leaning more
towards HAF, MRY, and SNS developing MVFR CIGs while the HRRR keeps
skies clear. Leaning more towards guidance from the HRRR with the
thought being drier air and strong northerly winds over the ocean
will keep stratus from being widespread. The main concern for the
TAF period is the continuation of gusty northwesterly winds with
gusts between 25 to 35 knots expected through this evening. Winds
will pick up through the evening hours before diminishing overnight.
Northwesterly winds strengthen again during the day tomorrow, but,
winds will be weaker with gusts peaking around 20 to 25 knots.

Vicinity of SFO...VFR through the TAF period. Strong northwesterly
winds continue at SFO through this evening with highest confidence
in gusts between 30 to 35 knots. Winds will ease slightly overnight
but will remain fairly breezy through the TAF period. High
confidence that SFO will stay clear through the TAF period.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with low confidence that IFR-
MVFR CIGs will develop overnight. LAMP guidance suggests CIGs will
build in briefly overnight (approximately 10Z-15Z) but high
resolution HRRR guidance keeps MRY and SNS clear. Leaned more
towards HRRR guidance for the forecast with the thinking being that
dry conditions overnight will help prevent CIGs from developing
overnight. Gusty northwest winds continue through this evening
before winds ease overnight.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 219 PM PDT Sat Jun 21 2025

Widespread hazardous marine conditions persist over the waters
through early Sunday morning, with near-gale north breezes,
severe gale force gusts, and rough to very rough seas. The bays
will be more sheltered, but will still experience fresh to strong
northwest breezes. Winds will subside on Sunday, with fresh to
strong northwest gusts and moderate to rough seas through the end
of the next work week.

&&

.FIRE WEATHER...
Issued at 221 PM PDT Sat Jun 21 2025

Elevated to near critical fire weather conditions continue today
across the interior Central Coast, East Bay Hills, and interior
North Bay as another dry day with moderate to poor RH recovery is
expected for interior locations and areas of higher elevation,
especially for those above the marine layer. Winds will be breezy
to gusty as well, peaking around 35 mph, perhaps locally higher
at exposed elevations and wind prone gaps. Breezy to gusty winds
look to hold through Saturday night. There should be some
improvement in humidity into Sunday morning, especially if the
marine layer is able to deepen. Widespread critical fire weather
conditions are not expected within the district today, 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.

     Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Mry Bay.

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

     Gale Warning until 9 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-
     60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...Kennedy
MARINE...DialH

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