322
FXUS66 KMTR 081937
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1237 PM PDT Sun Sep 8 2024

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

.SYNOPSIS...
Issued at 1236 PM PDT Sun Sep 8 2024

Warm temperatures across the region persist into Monday, before a
deep upper level trough brings a major cooldown and breezy winds.

&&

.SHORT TERM...
(This evening through Monday)
Issued at 1236 PM PDT Sun Sep 8 2024

Satellite imagery shows the stratus deck continuing to impact the
immediate coast this afternoon. With the marine layer gradually
deepening through the next few days, expect the overnight stratus
coverage to increase. Fog is also possible throughout the valleys in
the early morning, especially near the coast and around the North
Bay.

An upper level trough over the Pacific Northwest is contributing to
slight cooling today into Monday, with high temperatures in the
upper 80s to mid 90s in the inland valleys, near 100 in the warmest
spots of the Central Coast, the 70s to the low 80s in the Bayshore,
and the 60s along the Pacific coast. Low temperatures hover in the
50s in the lower elevations with temperatures reaching into the
upper 60s and low 70s in the higher elevations. Onshore winds are
expected to be generally light, with gusts up to 20 to 25 mph in the
gaps, passes, and Salinas Valley.

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 1236 PM PDT Sun Sep 8 2024

More substantial cooling is expected to come Tuesday with the
development of a deep upper level trough descending from the Gulf of
Alaska. High temperatures drop into the upper 70s to the 80s in the
inland areas, the upper 60s and the 70s across the Bayshore, and the
upper 50s to the mid 60s on the Pacific coast. Winds will also pick
up with the sustained winds reaching the 20-30 mph range in the gaps
and passes. Some offshore flow is possible as the low moves into the
Intermountain West on Thursday and Friday, but strong offshore winds
are not expected.

CPC guidance suggests a lean towards temperatures below seasonal
averages and precipitation above seasonal averages into the third
week of September.

&&

.AVIATION...
(18Z TAFS)
Issued at 1018 AM PDT Sun Sep 8 2024

Expect widespread VFR into the afternoon with moderate to breezy
winds. VFR conditions and these winds last into the evening before
winds reduce and LIFR CIGS move inland around the Monterey Bay. CIGs
will build abound the SF Bay and farther inland in the late night.
This will bring IFR CIGS to SF Bay terminals, MVFR CIGS to SJC, and
LIFR CIGS building in the North Bay and Monterey Bay. Expect mostly
light winds overnight and through the late morning on Monday. These
light winds and inflow of moist air will allow for pockets of mist
and fog across much of the region. CIGS look to erode late Monday
morning, with widespread VFR and moderate to breezy winds that
afternoon.

Vicinity of SFO...VFR lasts into the evening. Breezy winds build
this afternoon but reduce and become moderate in the night as IFR
CIGs fill around the SF Bay. CIGS erode in the late morning on
Monday with breezy winds returning in the mid-afternoon.

SFO Bridge Approach...Similar to SFO

Monterey Bay Terminals...VFR lasts into the evening before IFR CIGs
move inland. Expect moderate to breezy winds through the evening
before winds reduce. CIGs fall to LIFR levels in the late night with
pockets of mist and fog affecting the terminals through much of

&&

.MARINE...
(Today through Friday)
Issued at 1018 AM PDT Sun Sep 8 2024

Moderate northerly to northwesterly winds continue into Monday
with occasionally gusty winds over the southern waters. An upper
level low pressure system arrives midweek bringing widespread
fresh to strong northwesterly winds and elevated wave heights
across the coastal waters. Unsettled conditions will then persist
through the end of the week as a second upper level low arrives
next weekend.

&&

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

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Murdock
MARINE...DialH

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