508
FXUS66 KMTR 200318
AFDMTR

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

...New UPDATE...

.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...
(00Z TAFS)
Issued at 411 PM PDT Wed Jun 19 2024

VFR currently across all terminals will continue into the early
evening hours when low stratus ceilings are expected to spread
across portions of the coastal areas, initially lowering ceilings
to MVFR at KSFO, KOAK and KMRY around sunset. The remainder of the
terminals are expected to follow suit around midnight and persist
through the overnight hours, eventually clearing out by late
morning Thursday.

Vicinity of SFO...MVFR ceilings are expected around sunset and
will persist through the overnight hours into Thursday morning.
Some uncertainty remains on the potential for IFR ceilings, but
have held off in the TAF attm.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR ceilings are expected to develop
around sunset tonight and may drop into IFR around midnight and
persist through the overnight hours, eventually clearing out by
late morning Thursday.

&&

.MARINE...
(Today through Monday)
Issued at 1109 AM PDT Wed Jun 19 2024

  Northwest winds increase again late this afternoon across the
northern waters, remaining gusty through the weekend and into the
next work week. Significant wave heights stay around 6-8 feet,
will build back up to 10-12 feet towards the end of the the
weekend as larger northwesterly swell returns.

&&

.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...JM
MARINE...AC

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