Alpine Park, California Weather Forecast Discussion

779
FXUS66 KMTR 221806
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1106 AM PDT Mon Sep 22 2025
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 321 AM PDT Mon Sep 22 2025
- Warming trend continues through Tuesday, areas of Moderate and
   Major HeatRisk
- Weak offshore flow Monday through Tuesday in the higher terrain
- Rain showers and isolated thunderstorm chances return Tuesday
   and lingering through midweek
&&
.SHORT TERM...
Issued at 321 AM PDT Mon Sep 22 2025
(Today and tonight)
Not much going on in the short term forecast as upper level ridging
builds into the region. This will lead to the marine layer
compressing some more, likely keeping stratus confined to coastal
areas and perhaps draining into a portion of the Salinas Valley.
This should quickly mix out by mid to late morning, leading to a
warm fall day. Temperatures today will rise into the up into the mid
80s to mid 90s for interior locations, while those closer to the
coast range from the mid 60s to mid 70s. With ridging holding in
place, a warmer night is on tap with temperatures ranging from the
upper 50s to mid 60s for interior valleys and the coast. For those
in higher elevations, low temperatures span the 60s to low 70s.
&&
.LONG TERM...
Issued at 321 AM PDT Mon Sep 22 2025
(Tuesday through Sunday)
Tuesday will be the warmest day this week, with widespread Moderate
HeatRisk across the Bay Area and smattering portions of the Central
Coast. The latest guidance actually brings Major HeatRisk to the
East Bay counties and even leaks into Santa Clara County. In
addition to that, the cutoff low that looms off west of Baja CA
begins to drift north. The following questions remain with this
system... how fast does it arrive and where does go. The latest
guidance has it tracking towards the Central Coast and tracking into
the Central Valley by mid to late week. Moisture will surge ahead of
it, potentially bringing showers as early as Tuesday afternoon but
more likely occuring late Tuesday into Wednesday. Thunderstorms will
be possible, currently favoring the Central Coast but perhaps
tracking all the way up into the North Bay. Storms should be
sufficient rain makers as PWATs range 1.0-1.4 inches, meaning dry
lightning should be limited.
As the low meanders towards the east on Thursday, conditions begin
to dry out. High temperatures return to near normal for this time of
year and continue into the weekend.
&&
.AVIATION...
(18Z TAFS)
Issued at 1106 AM PDT Mon Sep 22 2025
Stratus is receding along the coastline with conditions improving at
MRY, SNS, and HAF. VFR conditions everywhere through this
afternoon/evening with winds strengthening to 10 to 12 knots. Winds
look to ease overnight and become locally variable to slightly
offshore. Moderate confidence that any stratus that is able to
develop tonight will be limited to the coastline (HAF, MRY, and
SNS). Any stratus that is able to develop tonight looks to be
patchier in nature due to the influx of drier air. This may result
in needing to adjust the TAFs to include a TEMPO for stratus along
the coast tonight rather than having it as the prevailing condition.
Vicinity of SFO...VFR. A few low clouds continue in the vicinity of
SFO but are expected to clear out by this afternoon. Winds
strengthen during the afternoon with gusts peaking around 20 knots.
Winds decrease by tonight and become locally variable to slightly
offshore. Offshore winds are expected to be light (less than 6
knots) with the highest likelihood of occurrence 12Z-18Z.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Stratus is scattering out with VFR
conditions to continue through this afternoon/evening. Low to
moderate confidence in timing of stratus return this evening.
Leaning towards stratus returning at least temporarily tonight with
guidance indicating it could return as early as 03Z. Put stratus in
as prevailing from 09Z but this may need to be adjusted earlier or
transitioned to a tempo instead of prevailing depending on how
stratus develops with the influx of dry air today.
&&
.MARINE...
(Today through Saturday)
Issued at 1106 AM PDT Mon Sep 22 2025
Occasional strong gusts linger in the far northern outer waters
elsewhere moderate to fresh winds continue. This will result in
steep seas across the northern outer waters, especially for
waters near and north of Point Reyes. Northwesterly swell will
continue through the entire period with wave heights gradually
easing. Waters south of Point Pinos will be prone to 12 to 15
second period southerly swell, though wave heights will average
between 2 and 3 feet.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...KR
LONG TERM....KR
AVIATION...Kennedy
MARINE...Murdock
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NWS MTR Office Area Forecast Discussion