803
FXUS66 KMTR 181624
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
924 AM PDT Wed Sep 18 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 1252 AM PDT Wed Sep 18 2024

Chance of scattered showers today, tapering off from north to
south gradually through Thursday morning. A warming trend is on
tap for the rest of the week with seasonal normal temps expected
by the weekend.

&&

.UPDATE...
Issued at 924 AM PDT Wed Sep 18 2024

Precipitation over the region has been mainly across the northern
Santa Cruz Mountains and into the East Bay with reports up to 0.06"
at Rocky Ridge (RGEC1). However, expecting rain to increase over the
North Bay in the next couple of hours as a rain band approaches the
region. As the low pressure center remains offshore, rain is
expected to be less widespread as once thought with the region
picking up around a trace to a few hundredths of an inch through the
afternoon and evening. That said, the forecast remains on track with
no updates anticipated at this time.

&&

.SHORT TERM...
(Today and Thursday)
Issued at 1252 AM PDT Wed Sep 18 2024

The next system is currently moving in, made noticeable by the
influx of higher cloud cover through the evening. As of about
midnight, the surface low was located just off the coast of
Oregon. The low will move southward through this morning, bringing
light rain chances to the Bay Area by mid-to-late morning. There
is a slight chance (~15%) of thunder during this time period,
mainly in the North Bay. As the low moves through, moisture
wrapping around the back side will affect areas south of the Bay
Area, including the Central Coast, by the middle of Thursday
morning. There is also a slight chance of thunder here during this
time. Though a small chance, there could be some terrain
enhancement over the Santa Lucia, resulting in isolated, brief
heavier rain than what will be seen elsewhere. Shower activity
ends gradually Thursday evening as the low moves inland.

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 1252 AM PDT Wed Sep 18 2024

A warming trend will kick off Friday into the weekend as the upper
low exits and confidence grows in an a broad upper level ridge
situated off the west coast. Temperatures through the weekend are
expected to be near seasonal normals. Warming continues into early
next week where we will begin to see slightly above normal
temperatures.

&&

.AVIATION...
(12Z TAFS)
Issued at 452 AM PDT Wed Sep 18 2024

Mid-level clouds as well as IFR and MVFR CIGs are moving through
the area and look to last through the morning with light rain
expected in the mid to late morning. Pockets of drizzle and mist
will affect the coast as well as the Bays and STS in the late
night ahead of the rain chances and lingering slightly after.
Winds stay light to moderate through the morning. Widespread VFR
returns for the TAF sites into Wednesday 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 slightly early Wednesday evening, affecting both bays
with IFR and MVFR CIGS, with low clouds becoming widespread later
that night.

Vicinity of SFO...MVFR CIGs and last into the late morning with
some shower activity in the mid to late morning. Expect light
winds to become more moderate in the afternoon. CIGs erode as
winds build in the early afternoon. Winds will reduce slightly
into Tuesday evening and MVFR CIGs return in the late evening and
early night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR/IFR CIGs with mist and drizzle
ahead of light scattered showers in the to late mid morning. CIGs
scatter and winds become more moderate into Wednesday afternoon as
showers exit. MVFR CIGs return early Wednesday evening as winds
reduce.

&&

.MARINE...
(Today through Monday)
Issued at 924 AM PDT Wed Sep 18 2024

Northwesterly winds will become gusty across the outer waters by
late Wednesday. Seas will be moderate, building to become rough in
the outer waters by Thursday. Unsettled conditions will continue
over the outer waters through the weekend. Showers continue over
the coastal waters through this afternoon. There is up to a 12%
chance for thunderstorms in the mid morning which could produce
lightning, locally heavy rainfall, locally gusty winds.

&&

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

&&

$$

UPDATE...RGass
SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Murdock
MARINE...Kennedy

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