Angwin, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

627
FXUS66 KMTR 181158
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
458 AM PDT Wed Jun 18 2025

...New AVIATION...

.SYNOPSIS...
Issued at 248 AM PDT Wed Jun 18 2025

Today will be the warmest day of the week, cooling trend into the
weekend begins tomorrow, along with gusty onshore flow setting
late tonight.

&&

.SHORT TERM...
(Today and tonight)
Issued at 248 AM PDT Wed Jun 18 2025

Today will be the warmest day of the week with bright sunshine
inland and marine stratus clearing by the afternoon along our
coastal areas as well. Deeper, gusty onshore flow will begin to
overspread our area later tonight and persist into the weekend. The
gusty winds later tonight into early Thursday may reach 30-40 MPH
across elevated inland areas along with typical passes and gaps,
with 40-50 MPH gusts possible along the immediate coast, especially
near the Bay Area, Big Sur and the Santa Lucia coastlines.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 248 AM PDT Wed Jun 18 2025

Gusty winds, will persist through late Saturday and begin to ease by
early Sunday morning after the second and stronger of 2 shortwave
troughs associated with a closed low slowly moves inland from the
Pacific Northwest. Extended guidance is struggling with our pattern
for the beginning of next week and beyond. A strong dome of high
pressure centered over the Ohio River Valley this weekend may result
in a slow moving cut-off low to spin off of the second stronger
trough passage on Sunday. That could result in weak offshore flow
increasing fire weather concerns, especially if it lingers with no
where to go, blocked by high pressure to the east.

&&

.AVIATION...
(12Z TAFS)
Issued at 458 AM PDT Wed Jun 18 2025

Stratus has started to spread into the SF Bay and into the Monterey
Bay coastline. Highest confidence in IFR CIGs persisting through mid
to late morning before VFR conditions prevail the remainder of the
day. CIGs look to be on the LIFR-IFR border across the Bay Area with
highest confidence in LIFR conditions at HAF. Gusty onshore flow
returns during the afternoon/evening with winds slightly weakening
overnight. Low level wind shear is expected at STS late this evening
into tomorrow morning due to strong directional and speed shear in
the lower levels. Confidence is low as to the return of stratus this
evening/overnight. NBM guidance shows stratus returning closer to 03-
06Z but higher resolution guidance suggests it could be delayed to
late overnight or not return at all. For now, highest confidence
that stratus will impact coastal sites (HAF) but lower confidence
that it will extend into the interior Bay Area/Central Coast.

Vicinity of SFO...Patchy stratus is starting to move into SFO with
the potential for temporary IFR CIGs to develop through 16Z. Gusty
west to northwesterly winds return this afternoon/evening with gusts
peaking around 30 knots. Winds ease slightly by the
evening/overnight hours but are expected to remain breezy through
the end of the TAF period. Stratus chances increase after 10Z with
LAMP guidance highlighting increased potential for stratus from 11Z
to 17Z. However, confidence is low as to the timing of stratus
return and how far inland it will extend with high resolution
guidance showing stratus confined closer to the coastline. For now
leaning more towards high resolution guidance but that may need to
be updated in additional TAF issuances.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR conditions persist through mid to late
morning before VFR conditions return. Moderate northwest winds
develop during the afternoon/evening hours before easing slightly
overnight. Guidance is mixed as to if stratus will reach MRY and SNS
tonight with high resolution showing a more optimistic forecast (no
stratus) compared to the NBM and LAMP guidance. Stratus and MVFR-IFR
CIGs are slightly more likely to reach MRY than SNS tonight with
stratus chances increasing after 03-06Z at MRY. If stratus does
reach SNS it is likely to not return until after 09Z-12Z with VFR
conditions persisting for much of the night. &&

.MARINE...
(Today through Monday)
Issued at 248 AM PDT Wed Jun 18 2025

Gale Warnings are in effect for the coastal jet areas south of
Point Reyes and Point Sur and across the outer coastal waters.
Hazardous conditions continue through the forecast period with
gusty northwesterly winds and moderate to rough seas continue.
Significant wave heights build to 10 to 12 feet across the coastal
waters Thursday into the weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for Mry Bay-SF Bay N of Bay Bridge.

     Gale Warning until 9 AM PDT Thursday for 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.

     Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt
     Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 3 PM PDT this afternoon for Pigeon Pt
     to Pt Pinos 10-60 NM.

     Gale Warning from 3 PM this afternoon to 9 AM PDT Thursday for
     Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Kennedy
MARINE...Kennedy

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