684
FXUS66 KMTR 180623
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1123 PM PDT Tue Sep 17 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1233 PM PDT Tue Sep 17 2024

The next weather system will bright light rain to parts of the
region on Wednesday and then taper off from north to south on
Thursday. A warming and drying trend is expected by this upcoming
weekend and into early next week.

&&

.UPDATE...
Issued at 924 PM PDT Tue Sep 17 2024

At this hour, mid level clouds are passing through the region ahead
of our next cold front. As a result, skies are overcast across the
area, and temperatures are on the cool side sitting in the mid 50s
for most locations. Temperatures are running 1-2 degrees cooler
compared to this time yesterday in the interior regions, and
generally 1-2 degrees warmer around the bays and along the
immediate coastline.

Chances of light rain are still expected for early Wednesday
morning. Most regions will only see a few hundredths of rainfall,
with the wettest locations (generally higher elevations) only seeing
around a tenth. Isolated peaks may see amounts closer to 0.2" at
most. All for now.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 1233 PM PDT Tue Sep 17 2024

Another upper level low will approach the coast tonight and move
across on Wednesday brining generally light rainfall to the region.
Coastal drizzle will be possible ahead of the system tonight but
transition to light rain showers throughout the day tomorrow. By
tomorrow afternoon, the greatest potential for thunderstorms will be
across the North Bay with a ~15% (a non-zero chance elsewhere).
Rainfall amounts are expected to be light, not amounting to more
than 0.10" in most locations expect for locally higher totals in the
coastal ranges or where any stronger showers develop. Lastly, winds
will not be a concern with this passing system with only 15-25 mph
onshore gusts.

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 1233 PM PDT Tue Sep 17 2024

Rain showers will linger into Thursday morning across the Central
Coast, tapering off from north to south throughout the afternoon and
ending by the evening. Friday looks to remain cool as the mid/upper
level trough begins to exit the region but still having an
influence.

Temperatures over the weekend will trend upward towards seasonal
averages. The marine layer also looks to return as a result with
night and morning low clouds likely into next week. Low clouds will
the retreat to the coast by the afternoon each day throughout the
week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1122 PM PDT Tue Sep 17 2024

Mid-level clouds as well as IFR and MVFR CIGs build through the
night last into the mid to late 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 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 some shower activity in the mid morning.
Expect light to moderate winds overnight. 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 mid morning. CIGs scatter and
winds become more moderate into Wednesday afternoon. MVFR CIGs
return early Wednesday evening as winds reduce.

&&

.MARINE...
(Tonight through next Monday)
Issued at 1122 PM PDT Tue Sep 17 2024

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

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

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

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