337
FXUS66 KMTR 211017
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
317 AM PDT Sat Sep 21 2024

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

.SYNOPSIS...
Issued at 315 AM PDT Sat Sep 21 2024

Gradual warming continues this afternoon, though todays highs will
still be at or slightly below normal for most locations across our
area. The potential for moderate HeatRisk Monday and Tuesday remains
in the forecast.

&&

.SHORT TERM...
(Today and tonight)
Issued at 315 AM PDT Sat Sep 21 2024

High pressure expanding across our area today and tomorrow will
result in quiet weather with gradual warming today and tomorrow.
Marine boundary layer (re: Ft Ord profiler) was steady at around 2k
ft yesterday, with similar low level onshore flow persisting today.
Low level stratus will clear farther inland by mid morning over the
Bay Area and late morning around gaps and valleys around Monterey
Bay. Some low stratus will linger over coastal communities this
afternoon, but will see more of a mix of sun and clouds than what
was realized on Friday. This will help temps near the coastline get
in on the gradual warming that will occur farther inland. Tomorrow
will be similar, just a few degrees warmer as H50 heights continue
to slightly increase.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 315 AM PDT Sat Sep 21 2024

A weak upper level low begins to develop over the California Central
Coast tomorrow interrupting the expanding area of high pressure to
our west over open water. Deterministic guidance is in a little
better agreement with the evolution of the upper level disturbance
than in previous runs. The weak closed low wanders southward
Monday, lifting back to the north offshore of our area on Tuesday,
and then farther north to be absorbed by the Polar Jet on
Wednesday. The net result appears to be less impactful heat event
for Monday and Tuesday than previously thought, though moderate
HeatRisk remains a possibility for many interior locations for
both Monday and Tuesday. Persistent, offshore upper level
troughing for the second half of next week will help cool daytime
temps back to around seasonal averages for Wednesday and beyond.

&&

.AVIATION...
(06Z TAFS)
Issued at 1137 PM PDT Fri Sep 20 2024

Coastal stratus and fog /LIFR-IFR/ will move inland on onshore
winds tonight and Saturday morning. Conditions improving to MVFR-VFR
back to the coastline and bays by late morning and early afternoon
Saturday.

Vicinity of SFO...VFR, then tempo IFR ceiling 10z-14z Saturday with
prevailing IFR ceiling until 18z. Onshore wind 5 to 15 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus and fog /LIFR-IFR/ tonight and
Saturday morning, conditions improving to MVFR-VFR by late morning
and afternoon. Onshore winds 5 to 15 knots.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 838 PM PDT Fri Sep 20 2024

Northwesterly breezes will be gentle to moderate, with strong
gusts over the outer waters. Seas will be moderate, continuing to
build and remain rough in the outer waters. Winds decrease and
seas abate beginning Tuesday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT Sunday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Canepa
MARINE...Sarment

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