Mount Hamilton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

053
FXUS66 KMTR 201211
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
511 AM PDT Fri Jun 20 2025

...New AVIATION...

.SYNOPSIS...
Issued at 323 AM PDT Fri Jun 20 2025

Cooler than normal temperatures today will continue into the
weekend. Elevated fire weather concerns today and tomorrow,
especially interior elevated grassy areas where gusty winds will
combine with dry conditions and increasing fuels. King tide coastal
flooding possible Sunday into the beginning of next week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 323 AM PDT Fri Jun 20 2025

A deepening upper level low has begun shifting south out of the Gulf
of Alaska into the Pacific Northwest early this morning. A
tightening height field gradient over NorCal and the Central Coast
will result in gusty onshore flow persisting today and tonight.
Isolated gusts in the 40s and 50s occurred Thursday afternoon and
evening and should see similar speeds for today. Temperatures will
continue to be cooler, 5-10 degrees below normal for this time of
year.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 323 AM PDT Fri Jun 20 2025

Saturday morning temperatures may come with a little chill in the
air with H85 temps dropping into single digits, and potentially
approaching a daily record minimum (~5C) according to the sounding
climatology kept by the Storm Prediction Center. Despite the cooler
temperatures, gusty winds and continued dry conditions along the
elevated interior eastern hillsides will lead to elevated fire
weather concerns, highlighted in the day two SPC Fire Weather
Outlook. By early Sunday morning the strongest of several trough
axis` exits east with wind speeds easing somewhat, and gradually
improving RH recoveries helping to mitigate widespread fire weather
concerns. Plenty of uncertainty remains in the synoptic pattern for
the beginning of next week and beyond until models get a handle on
the evolution of the large dome of high pressure across the eastern
half of the country.

&&

.AVIATION...
(12Z TAFS)
Issued at 509 AM PDT Fri Jun 20 2025

Currently a mixed bag of IFR-VFR at the terminals with patchy
stratus. High confidence in VFR prevailing by the afternoon with the
help of dry air advection. Strong and gusty onshore winds are
expected through the TAF period.

Vicinity of SFO...Currently MVFR with gusty westerly flow. Stratus
is somehow managing to exhibit a BKN on the METARs, but it is only
over the western half of the terminal and only over land.
Nonetheless, it is not expected to last long as sunrise quickly
approaches and dry air gets advected. Westerly/westnorthwesterly
winds will strengthen through the morning with gusts up to 45 knots
to be expected in the afternoon and evening.

SFO Bridge Approach...The approach will likely remain clear even as
MVFR ceilings are observed at both OAK and SFO, remaining confined
to the land.

Monterey Bay Terminals...Currently MVFR with southwesterly flow at
MRY and MVFR with westerly flow at SNS. High confidence in VFR by
the afternoon. Gusty onshore winds will prevail through the TAF
period.

&&

.MARINE...
(Today through Wednesday)
Issued at 323 AM PDT Fri Jun 20 2025

Widespread hazardous marine conditions will persist through the
weekend with strong northwesterly breezes, gale force gusts, and
rough to very rough seas. Fresh to strong northwesterly breezes
and moderate to rough seas are expected Monday and Tuesday.

&&

.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 9 PM PDT Saturday for Mry Bay-SF Bay
     N of Bay Bridge.

     Gale Warning until 9 PM PDT this evening 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 3 PM PDT this afternoon for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Sarment
MARINE...Sarment

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