-- Discussion containing changed information from previous version are highlighted. --
205
FXUS66 KMTR 200559
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1059 PM PDT Wed Jun 19 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1259 PM PDT Wed Jun 19 2024

Trough pattern slowly degrades as a ridge builds late this week.
Warming trend through the end of the week into the weekend. Above
average temps by the weekend.

&&

.UPDATE...
Issued at 816 PM PDT Wed Jun 19 2024

The marine layer returned today and made its presence known. Some
remarkable 24 hour trends were noted: 5 to 15 degrees colder,
relative humidity increased by 70 percent in some spots, and winds
were generally lighter. Not only did this bring some relief, but
more importantly it mitigated larger fire weather concerns. Even
saw an uptick in moisture on a handful of automated 10 hr fuel
sticks.

For the rest of this evening and overnight: the marine layer
lurking along the coast through the day has already begun to
spread inland. Ft Ord profiler even shows that it has deepened and
is now around 1700 feet. Latest SFO-SAC is a robust 4mb.
Therefore, expect the marine layer to continue to push inland
overnight with slightly better coverage than Wednesday more. A
few models even suggest some patchy drizzle along the coast and
terrain favored locations.

No update is needed this evening. As mentioned below the biggest
weather impact the next seven days will be the heat up over the
weekend.

MM

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 1259 PM PDT Wed Jun 19 2024

Cooler temps today with ample sunshine across the area...unless
you live between Half Moon Bay and the Marin Headlands, or Bodega
Bay. Really a "blue sky day" these next couple of days with
little-to-no weather-related impacts immediately apparent.
Stratus in the mornings and clear for most in the afternoons. The
next couple of days will be great to do some outdoor activities
and get some chores done ahead of the weekend if you`re sensitive
to heat.

&&

.LONG TERM...
(Friday through next Tuesday)
Issued at 1259 PM PDT Wed Jun 19 2024

Guidance continues to provide high confidence in a building ridge
through into the weekend. Not a stout, high amplitude ridge by any
means, but 500 mb heights rise through the next several days
providing a gradual warm up through the latter half of the week.
By Saturday we are looking at afternoons highs in the lower 100s
for inland locations such as interior Monterey/San Benito, eastern
Alameda and Contra Costa, and northern Napa and Sonoma counties.
Other locations look to range from the lower 80s to lower 90s with
60s to lower 70s along the coast. A spread of minor to moderate
HeatRisk across the area Saturday, so will likely need some heat
highlights...will evaluate where those are needed in the coming
shifts.

&&

.AVIATION...
-- Changed Discussion --
(06Z TAFS)
Issued at 1059 PM PDT Wed Jun 19 2024

MVFR/IFR CIGS have formed over the Coast and Bays with CIGs
continuing to move inland and are expected to affect all of the TAF
sites overnight. Pockets of fog look to form into the early morning
in the North Bay and along the coast. Winds be light to moderate
through the late morning before breezy winds arrive into the
afternoon. CIGs dissipate for all but the Monterey Bay terminals in
the mid to late morning, with those terminals seeing some brief
clearing into the afternoon. Winds reduce into Thursday evening as
MVFR and IFR CIGs begin to affect the Monterey Bay and SF Bay
terminals.


Vicinity of SFO...IFR lasts through the late morning with moderate
westerly winds. Expect CIGs to clear as a round of breezy winds
start build with peak gusts around 26 kts. IFR CIGs arrive in the
evening, with winds reducing into the night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR lasts through the night and into
Thursday afternoon light to moderate winds. CIGS erode into the mid
to late morning as moderate to breezy winds arrive. Winds at the
terminals reduce into the evening as IFR CIGs move inland.
-- End Changed Discussion --


&&

.MARINE...
-- Changed Discussion --
(Tonight through next Tuesday)
Issued at 1059 PM PDT Wed Jun 19 2024

  Northwest winds continue, with the strongest gusts across our
northern waters. Significant wave heights of 6-8 feet will persist
until the end of the week, when they build back up to 10-12 feet
over the outer waters for the weekend, when northwest winds
increase once again.
-- End Changed Discussion --

&&

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

     Small Craft Advisory until 9 AM PDT Friday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Murdock
MARINE...JM

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