672
FXUS66 KMTR 211127
AFDMTR

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

...New AVIATION, MARINE...

.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...
(12Z TAFS)
Issued at 427 AM PDT Sat Sep 21 2024

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

Vicinity of SFO...IFR ceiling until 18z later this morning. IFR
ceiling tonight and Sunday morning 08z-18z. Onshore wind 5 to 15
knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus and fog /LIFR-IFR/ until late
morning and early afternoon. Stratus and fog /LIFR-IFR/ tonight
and Sunday morning. Onshore winds 5 to 15 knots.

&&

.MARINE...
(Today through Thursday)
Issued at 423 AM PDT Sat Sep 21 2024

Northwesterly winds gusty over the outer waters, lighter winds
elsewhere across the 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...Canepa

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