143
FXUS66 KMTR 122051
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
151 PM PDT Wed Jun 12 2024

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
Issued at 1234 PM PDT Wed Jun 12 2024

Quiet through the rest of the week. Near normal temps by the
weekend. Increasing confidence for high wind potential and
increased fire danger Sunday into early next week.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 1234 PM PDT Wed Jun 12 2024

Noticeably cooler temps today across the area as the upper level
ridge moves out and the marine layer deepens in response to a weak
mid level shortwave trough. Additionally, more robust marine
stratus associated with moisture from a weak disturbance off the
coast of southern CA will continue to linger for areas from around
Santa Cruz to the Big Sur coast. A few degrees warmer for
Thursday as the shortwave kicks out. Overall not much in the way
of impactful changes in the short term. Pleasant day ahead on
Thursday with little in the way of heat risk.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 1234 PM PDT Wed Jun 12 2024

Heading into the weekend will be relatively quiet as temps cool a
bit again down to around seasonal normals. The real story will be
later in the weekend and into early next week. A deep upper low
currently up in the Gulf of Alaska becomes dislodged and moves
into the Pacific Northwest, kicking off another deep disturbance
sliding into the West Coast/Great Basin. Well advertised by
ensemble cluster analysis, there is high confidence in this
pattern change taking place Sunday into Tuesday. Placement of the
upper level trough axis is key when determining where the
strongest winds will be and their direction. There is higher
confidence that the strongest winds will remain over the waters
and near coastal areas, including more inland coastal gaps such as
the Petaluma Gap, San Bruno Gap, and other NW-SE oriented valleys.
While we aren`t expecting any widespread offshore winds as of this
forecast, the positioning of the trough will ultimately be the
deciding factor, so stay tuned to future updates as confidence
gradually increases. With grasses and fine fuels drying out
rapidly, it looks like the Sunday-Monday timeframe is one to watch
when it comes to elevated fire danger, particularly in the North
Bay where fine fuels are drier than elsewhere around the Bay Area
and Central Coast. For now, moisture recovery looks decent going
into the weekend as winds should remain onshore, but we are
keeping a close eye on the positioning of the trough and will
update messaging accordingly.

&&

.AVIATION...
(18Z TAFS)
Issued at 1028 AM PDT Wed Jun 12 2024

Satellite shows the stratus continues to linger over Monterey Bay.
With the slight eddy rotation, expect ceiling to linger longer into
early afternoon. Otherwise, VFR for the remainder of the terminals.
MVFR-IFR conditions will return for Monterey Bay late afternoon and
MVFR conditions will build for North Bay late tonight, as the other
remaining terminals will remain VFR. With the building marine layer,
expect some scattered low clouds to reach some of the remaining
terminals, but moderate confidence that conditions will remain VFR.
Winds will become breezy and gusty this afternoon into the evening,
before becoming light to moderate overnight.

Vicinity of SFO...VFR continue with N/NW moderate winds. Onshore
winds will build to breezy and gusty this afternoon up to 25 knots
before returning to moderate by the night. Models hint at MVFR
tonight but had low confidence to include in TAFs at this moment but
included a SCT group to indicate low clouds will surround the
airport.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR conditions continue but ceilings are
slowly lifting. Models show ceilings may not lift to VFR through the
TAF period, but confidence is low so expect brief VFR near 20-21Z.
MVFR will have a early return near 23Z. SW winds will continue
through the TAF period with increasing speeds near the afternoon
with possible gusty up to 20 knots. The SW direction winds will make
it harder for ceilings to clear and will allow for a early return of
MVFR-IFR conditions this afternoon into Thursday morning.

&&

.MARINE...
(Today through Monday)
Issued at 1028 AM PDT Wed Jun 12 2024

Northwesterly winds continue over the northern waters through the
end of the week with gale force gusts possible over the northern
waters through the day today, but diminish into the late night
tonight. Widespread strong northwesterly winds with gale force
gusts will build in by the weekend and continue into next week.
Significant wave heights diminish later today to become 10-12 feet
over the outer waters, and last through the remainder of the
week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt
     Reyes 0-10 nm.

     Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10-
     60 NM.

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

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...SO
MARINE...SO

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