323
FXUS66 KMTR 280708
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1208 AM PDT Tue May 28 2024

...New AVIATION...

.SYNOPSIS...
Issued at 131 AM PDT Mon May 27 2024

Warmer today as a warming trend continues through the week.
Afternoon highs slightly above normal on tap for next weekend.

&&

.UPDATE...
Issued at 715 PM PDT Mon May 27 2024

Inland areas were generally at seasonal averages this afternoon
while coastal locations were up to 9 degrees below normal for this
time of year. This was thanks to a marine layer at around 1,800-
2,000 feet in depth that refused to mix out. The warming trend will
take a pause for tomorrow and will see similar temperatures as we
did today once low clouds retreat to the coast. Low clouds are
forecast to return tonight and spread locally inland across the
Central Coast, around the San Francisco Bay Area, and places such as
Napa. The ongoing forecast remains on track with no updates needed
at this time.

&&

.SHORT TERM...
Issued at 123 PM PDT Mon May 27 2024
(This evening through Tuesday)

Interesting current weather situation around the Bay Area and
Central Coast. It`s all about the details. Generally speaking,
morning marine layer was slow to clear back to the coast and for
the coast clouds never cleared. As for the details, moderate
onshore flow (SFO-SAC) and falling 500 mb heights likely
contributed to the slow clearing of morning clouds. If one were to
overlay the morning layer footprint and 24 hour trends one would
see cooler temps today where the marine layer had some influence.
Areas outside of the marine layer footprint are running a little
warmer than yesterday.

Heading into Tuesday - the marine layer lurking along the coast
will move inland again so no drastic change with overall sensible
weather from the last few nights. One change will be the longwave
pattern overhead. The ridge the brought our recent warmup will
flatten as a broad upper level trough sweeps through the PacNW.
The flattening ridge will keep the marine layer established with
overall cooling temperatures, still below seasonal averages.

&&

.LONG TERM...
Issued at 140 PM PDT Mon May 27 2024 (Tuesday night through next
Sunday)

The cooling trend will be short-lived as the flattened ridge
begins to build back over the region with warming 850 mb temps and
rising 500 mb heights. Still looks like night/morning clouds with
inland afternoon sunshine will persist. The warming trend will
continue into next weekend. Far inland locations will reach the
low 90s by week`s end. The interior warmth on Friday will lead to
moderate HeatRisk.

&&

.AVIATION...
(06Z TAFS)
Issued at 1208 AM PDT Tue May 28 2024

Stratus will build into area terminals throughout the night, leading
to predominantly IFR/MVFR CIGs across coastal terminals. Only far
inland terminals are expected to remain VFR through the night
tonight, though a FEW low clouds may build in the mid morning of
Tuesday. Late clearing of stratus is expected, towards the late
morning. Into the afternoon, gusty onshore winds are expected, with
gusts generally in the 20-25 knot range, higher at SFO. Winds will
be slow to ease, with breezy conditions lingering through the end of
the TAF period.

Vicinity of SFO...MVFR conditions last through the late morning. At
this time, highest confidence is in an 18Z clearing, ushering in VFR
conditions as westerly winds begin to increase. Gusts will steadily
build in the afternoon, reaching up to around 30-33 knots at the
strongest. Into the late night, winds are slow to ease with gusts
above 20-25 knots persisting as night begins to fall. It is not
until the early morning of Wednesday that gusts are expected to
decrease, with sustained winds lowering to become breezy.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR/IFR conditions persist through the
late morning. Stratus expected to begin to lift and mix out towards
18Z, bringing a return of brief VFR conditions. Winds increase out
of the NW to become breezy around 15 knots, with occasional gusts
closer to the 20 knot range. Stratus returns bringing IFR/MVFR CIGs
in the early evening.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 442 PM PDT Mon May 27 2024

Breezy to gusty northwest winds continuing across the coastal
waters through the week with westerly breezes increasing each
afternoon and evening across the bays. Wave heights beginning to
increase by the middle of the work week up to 11 to 13 feet.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Wednesday for Pigeon Pt to
     Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to
     Pt Reyes 10-60 NM.

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

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...AC
MARINE...SO

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