555
FXUS66 KMTR 200545
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1045 PM PDT Thu Sep 19 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 130 PM PDT Thu Sep 19 2024

There remains a chance for showers and thunderstorms across the
interior Central Coast through this evening. A warming trend is on
tap by this weekend and into early next week with temperatures
rebounding to near or slightly above seasonal averages.

&&

.UPDATE...
Issued at 800 PM PDT Thu Sep 19 2024

The KMUX radar still remains active picking up lingering showers
over Southern Monterey/San Benito counties this evening. Most of
the activity occurred during the pre-dawn hours into early this
morning as far as thunderstorms go. Since then, there`s been a
gradual decline since then. Latest analysis from NUCAPS and KVBG
soundings show some instability aloft with some inhibition near
the lingering shower activity. However, further analysis from
radar/MRMS data reveals not a lot of vertical depth or ice
through any convective column leading to no lightning production.
All that being said, a few showers to the east of San Benito may
produce a strike or two this evening, but not much more than that.
The storm motion with these convective showers has been slow
leading to wetting rains across some parts of Monterey county.
Lockwood has recorded 0.28" and a station near Greenfield measured
0.42". Not bad for September.

On the flip side...while the instability inland is aloft a much
more stable regime persists at the coast with a marine layer near
1500 feet. This marine layer will deepen slightly and move inland
overnight night.

No update needed this evening, but we`ll be monitoring the nearby
precip/convection.

MM

&&

.SHORT TERM...
(This evening through Friday)
Issued at 130 PM PDT Thu Sep 19 2024

The upper level low that brought rain showers and thunderstorms to
the interior Central Coast this morning remains south of the
Monterey Bay region. As it moves onshore, there will be a chance of
additional convection this afternoon over the aforementioned region
as the air mass aloft is marginally unstable. The warmest conditions
this afternoon will be across the North Bay and East Bay with
interior areas warming into the low 80`s with 60`s and 70`s as you
move closer to the coast.

The marine layer is projected to deepen tonight bringing low clouds
locally inland to the coastal adjacent valleys. The upper level
trough will push further inland Friday, yet its effects will still
linger with temperatures remaining below seasonal averages. Tomorrow
expecting more widespread 80`s across the interior with the
potential for a few spots to reach 90 degrees such as Lake
Berryessa. Elsewhere, 60`s and 70`s near the coast and San Francisco
Bay Shoreline.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 130 PM PDT Thu Sep 19 2024

Warming will continue into Saturday and moreso on Sunday as a ridge
of high pressure builds over the eastern Pacific. HeatRisk increase
by Monday and Tuesday with moderate risk across the interior. During
this time, evening clouds will spread into the coastal adjacent
valleys through early morning and then retreat back to the coast by
the afternoon.

&&

.AVIATION...
(06Z TAFS)
Issued at 1045 PM PDT Thu Sep 19 2024

Coastal stratus and fog /LIFR-IFR/ moving inland on onshore winds
tonight and Friday morning, MVFR-VFR farthest inland. Stratus and
fog mixing out back to near the coast and bays by late Friday morning
and afternoon.

Vicinity of SFO...Satellite shows stratus moving inland, at SFO tempo
IFR 06z-10z then IFR prevailing to 16z, MVFR to 1730z Friday. West
to southwest wind 5 to 15 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR-IFR due to stratus and fog tonight
and Friday morning, conditions improving to MVFR-VFR by late Friday
morning and afternoon. Onshore winds mainly 5 to 15 knots.

&&

.MARINE...
(Tonight through next Wednesday)
Issued at 1037 PM PDT Thu Sep 19 2024

Northwesterly breezes will be gentle to moderate, with fresh gusts
over the outer waters through Monday. Seas will be moderate,
continuing to build and remain rough in the outer waters through
Monday. Winds decrease and seas abate Tuesday through the end of
the forecast period.

&&

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

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...Kennedy

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