892
FXUS66 KMTR 190943
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
243 AM PDT Thu Sep 19 2024

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

.SYNOPSIS...
Issued at 239 AM PDT Thu Sep 19 2024

There is a slight chance of showers and even a couple rumbles of
thunder over southern Monterey County later this afternoon and
early evening, with the best chances farther inland you go into
higher elevations. Locations under the influence of the marine
layer along the coast will be in the 60s and low 70s. Interior
locations away from the marine layer will be in the 70s to low
80s. A warming trend for this weekend into the beginning of next
week remains on track.

&&

.SHORT TERM...
(Today and tonight)
Issued at 239 AM PDT Thu Sep 19 2024

A positively tilted upper level low currently situated offshore in
the vicinity of Big Sur will continue to track south along the
California coastline toward Los Angeles today and eventually begin
to move inland over San Diego by tomorrow afternoon and evening. The
best chance for showers and/or thunderstorms will be farther inland
where orographic upslope flow enhances an otherwise weak
thermodynamic environment for convection. Highs today will
generally be 5-10 degrees below normal, and slightly warmer
tomorrow.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 239 AM PDT Thu Sep 19 2024

The upper level trough moving across our area today and tomorrow
will eventually shift inland over SOCAL by tomorrow evening.
Increasing H50 heights and thickness values over the weekend will
result in temperatures rebounding back up above normal by the end of
the weekend into the beginning of next week. A weak upper level
disturbance interrupts the ridging pattern off the coast of central
California by late Sunday into early Monday morning, while the
northern extent of the ridging amplifies over the Pacific Northwest.
The net result is warmer than normal temperatures and increasing
heat risk concerns the farther inland and north you go for the
beginning of next week. The warming trend may result in the need for
a heat advisory for those locations as soon as Sunday, but more
likely Monday and Tuesday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1128 PM PDT Wed Sep 18 2024

IFR and MVFR CIGs build through the night last into the mid to late
morning with some light rain lingering around the Monterey Bay and
Central Coast. Pockets of drizzle and mist will affect the coast as
well as the Monterey Bay and STS. Winds stay light to moderate
through the morning. Widespread VFR returns for the TAF sites into
Thursday afternoon, but status lingers on the immediate coast.
Expect moderate winds to build into the afternoon and linger into
the evening. Coastal cloud cover moves inland slightly early Tuesday
evening, affecting both bays with IFR and MVFR CIGS becoming
widespread later that night.

Vicinity of SFO...MVFR CIGs build into the late night and last into
the late morning with  light to moderate winds. Winds increase into
and become moderate in the mid afternoon. Winds will reduce slightly
into Thursday evening and MVFR CIGs return in the late evening and
early night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Lingering showers along with MVFR/IFR CIGs
last through most of the thing. CIGs lower into early Thursday with
mist and drizzle affecting the area. CIGs scatter and winds become
more moderate into Thursday afternoon. IFR CIGs return  Thursdsay
evening as winds reduce.

&&

.MARINE...
(Tonight through next Tuesday)
Issued at 1128 PM PDT Wed Sep 18 2024

Northwesterly breezes will be gentle to moderate, increasing to
become moderate to fresh over the outer waters overnight. Seas
will be moderate, building to become rough in the outer waters
overnight. There`s up to a 15% chance for thunderstorms through
tomorrow which could produce lightning, locally heavy rainfall,
locally gusty winds, and small hail.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
     Saturday for Pt Arena to Pt Reyes 10-60 NM.

&&

$$

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

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