-- Discussion containing changed information from previous version are highlighted. --
580
FXUS66 KMTR 260822
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
122 AM PDT Sun May 26 2024

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

.SYNOPSIS...
-- Changed Discussion --
Issued at 1237 AM PDT Sun May 26 2024

Warmer today as a warming trend kicks off through the week.
Afternoon highs slightly above normal on tap for next weekend.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(Today and tonight)
Issued at 1237 AM PDT Sun May 26 2024

Continued quiet weather to round out the weekend. Warmer today
compared to yesterday as the upper low responsible for the drizzle
the last couple of days finally moves out and a broad ridge builds
in its wake. Temperatures warm to around seasonal normals with
highs inland in the mid-to-upper 70s and lower 60s closer to the
coast. Though dry weather persists, as does onshore flow,
providing decent moisture return through the week.
-- End Changed Discussion --

&&

.LONG TERM...
-- Changed Discussion --
(Monday through Saturday)
Issued at 1237 AM PDT Sun May 26 2024

Seasonal temps last through the week with no real large-scale
change in the pattern. A progressive, deep upper low traverses
through the Pacific NW midweek to flatten the ridge a bit. This
will keep any further warming at bay through the middle of the
week, but isn`t expected to bring any other notable change to the
sensible weather. As this feature departs, the ridge builds back
and a secondary warming trend continues into the weekend. Not
staring down any major heat wave by any means, but there`s a good
chance our afternoon highs are slightly above normal by next
weekend.
-- End Changed Discussion --

&&

.AVIATION...
(00Z TAFS)
Issued at 605 PM PDT Sat May 25 2024

Diurnal surface warming and greater vertical mixing due to a
weakened lower level temperature inversion(s) have mostly mixed
out the low clouds today. Currently much of the forecast area is
VFR with exception of a few patches of low clouds and haze /MVFR/
along the coast.

The air mass is essentially unchanged at the moment, however
there are hints in the model output that another push of surface
to near surface cooler air will arrive from the northwest and
over the coastal waters overnight and Sunday morning, assisting
with redevelopment of low clouds /MVFR-IFR/; sea surface temps are
49F-54F, surface dewpoint temps are roughly the same and outgoing
radiative cooling tonight favor low cloud redevelopment. Warming
in the lower levels of the atmosphere will be slow to start tonight,
but is forecast to increase/consolidate through Sunday and Sunday
night resulting in the restrengthening of a lower level temperature
inversion (cap for stratus and/or fog development). The afternoon
Oakland upper air sounding showed the lowest inversion based near
2600 feet AGL, and two subsidence inversions were based at 4500 feet
AGL and at 8000 feet AGL.

Vicinity of SFO...BKN cloud cover has reduced to SCT cloud cover
with sufficient afternoon surface warming and mixing. Post sunset
however and incoming cooler air advection will combine to bring
back low clouds /MVFR/ mid-late evening; a moderate to high
confidence forecast. MVFR tonight and Sunday morning. Decided to
extend MVFR ceiling forecast to 21z Sunday before clearing takes
place based on the NAM humidity forecasts, combining with
aforementioned cooling to saturation. West wind 15 to 25 knots,
easing to near 10 knots tonight and Sunday morning, then westerly
15 to 20 knots Sunday afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Near high confidence VFR continues to
mid evening then MVFR-IFR developing due to low clouds. MVFR-IFR
tonight and Sunday morning mixing out to VFR by late morning. West
to northwest winds 10 to 20 knots decreasing to 5 to 10 knots by
late evening, west to northwest winds resuming to 10 to 20 knots
Sunday afternoon and early evening.

&&

.MARINE...
(Tonight through next Friday)
Issued at 908 PM PDT Sat May 25 2024

Fresh northwest breeze over the outer waters persists through
Memorial Day 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.  Wave heights beginning to increase mid-work week up to
11-13 feet. Otherwise mostly quiet marine conditions through the
forecast  period.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CA...None.
PZ...Small Craft Advisory until 3 AM PDT early this morning for
     Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-
     Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 3 AM PDT Monday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.
-- End Changed Discussion --

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Canepa
MARINE...Canepa

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