646
FXUS66 KMTR 251558
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
858 AM PDT Sat May 25 2024

...New UPDATE...

.SYNOPSIS...
Issued at 1259 AM PDT Sat May 25 2024

Cool with abundant overnight stratus through the weekend. Warming
and drying trend set for next week with temperatures around
seasonal normal.

&&

.UPDATE...
Issued at 857 AM PDT Sat May 25 2024

May gray in full effect this morning across the Bay Area and
Central Coast with widespread clouds, drizzle, and patchy fog.
Enough onshore flow is present that may gray filtered through the
Delta and up the Sacramento Valley. Morning balloon sounding out
of Oakland Airport puts the moist marine layer depth at 3k ft,
which is definitely on the upper end of marine layer depths.
Patchy fog: a few automated sensors have visibilities bouncing
between 3-5 miles. Patchy fog is also being seen on Bay Area
webcams. Drizzle: as noted below enough lift overhead led to
precipitation last night through early this morning. It was more
than just few wet roads as rain gages tipped a few hundredths to
as much at two tenths. Impressive to say the least with weak
forcing and moist low levels.

For the rest of the day - a gradual thinning of inland clouds will
continue through mid-late morning. Coastal areas will be the last
to clear out. In fact, hi-res guidance suggests that locations
around Monterey Bay and SF Peninsula Coast will struggle to clear
with patchy clouds lingering through much of the day.

No update needed this morning.

MM

&&

.SHORT TERM...
(Today and tonight)
Issued at 1259 AM PDT Sat May 25 2024

Deep, moist marine layer this morning allowing for stratus to push
well inland. Additionally, a weak passing trough has provided
just enough lift to bring drizzle to areas along the coast and in
the hills. Several locations along the SF Peninsula, East Bay
hills, and Central Coast have actually measured a few hundredths
of an inch here and there as a result. Skies will gradually clear
inland today with some coastal locations remaining in the clouds.
Another cool day with afternoon highs similar to yesterday.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 1259 AM PDT Sat May 25 2024

Warming and drying trend starts Sunday into the middle of next
week as a broad ridge builds across the West Coast. Afternoon
highs expected to be near seasonal normals by mid-to-late week.
Typical onshore flow pattern persists with overnight and morning
clouds clearing back to the shoreline each afternoon.

&&

.AVIATION...
(12Z TAFS)
Issued at 410 AM PDT Sat May 25 2024

Low stratus clouds are expanding across the region is morning
with a troughing pattern supporting a deep marine layer and
onshore winds. As with yesterday expect a slower erosion of
ceilings towards the coast during the afternoon. Low confidence in
exact clearing times around the Monterey Bay and at KSFO/KOAK as a
result, and there is a ~20% chance that clouds may stick around
longer than advertised in the current TAF. Breezy onshore winds
return this afternoon and evening.

Vicinity of SFO...Sub-VFR ceilings in low stratus will persist
through the morning (high confidence). There is a low potential
(~20%) for stratus lingering into the afternoon hours at or around
the terminal. Winds will remain breezy and onshore with gusts up
to 25 kt this afternoon. Low stratus returns/expands once again
tonight.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals...Sub-VFR conditions this morning in low
stratus with periods of minor visibility restrictions in -DZ.
Somewhat lower confidence in clearing times today, with most
indications suggesting clouds scatter out during the late morning
to early afternoon hours. However an alternate scenario would keep
low stratus around through the entire day. For now opted to show
some period of scattering out this afternoon but adjustments could
be necessary based on trends. Breezy onshore winds return this
afternoon and early this evening with low stratus expanding across
the area yet again.

&&

.MARINE...
(Today through Thursday)
Issued at 410 AM PDT Sat May 25 2024

Fresh northwest breeze over the outer waters persists through the
weekend creating hazardous conditions for small crafts. Fresh to
strong northwest and onshore winds across the coastal waters and
bays during the afternoons by early to mid next week. Otherwise
mostly quiet marine conditions through the forecast period.

&&

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

     Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt
     Reyes 0-10 nm.

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

     Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Sunday
     for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt
     Reyes 10-60 NM.

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

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...SPM
MARINE...Behringer

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