998
FXUS66 KMTR 210421
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
921 PM PDT Fri Sep 20 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 143 PM PDT Fri Sep 20 2024

Warming trend continues through the weekend into early next week,
with moderate HeatRisk possible inland Monday and Tuesday.

&&

.UPDATE...
Issued at 838 PM PDT Fri Sep 20 2024

Cloud cover is returning, and it`s coming in low with cloud
bases between 200 and 600ft. Fog will be close to follow as
conditions continue to cool through the night.

The night shift will have to keep an eye on that along with
ironing out the details of the early work week warm up in the
early morning forecast update.

Fun times for them!

-Murdock

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 143 PM PDT Fri Sep 20 2024

A warming trend was expected to start today as an upper level low
moves off to the east, but you wouldn`t know it from the 24 hour
temperature trends, which have not shown much warming from the same
time yesterday, and if anything, have ran up to five degrees cooler
across the valleys. The extensive stratus deck this morning and the
continuing onshore flow may have kept things cooler than what was
earlier forecast. Have bumped today`s high temperatures across the
inland valleys down to account for this. The current forecast calls
for high temperatures today to rise into the upper 70s to the lower
80s across the inland valleys, around the mid 60s to the mid 70s
along the Bayshore, and into the upper 50s to mid 60s along the
Pacific coast. Some more warming is expected tomorrow with the
warmest inland regions scraping into the low 90s.

Stratus has retreated back to the coastal regions and the Monterey
Bay region, where the clouds are expected to persist through the day
before the stratus extends inland this evening and overnight.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 143 PM PDT Fri Sep 20 2024

The fringes of an upper level ridge will impact the state through
the weekend into early next week, with the main impact being a
warming trend across the region. By the early part of next week,
high temperatures should peak into the mid to upper 90s across the
inland valleys and the upper 60s to the mid 70s across the Pacific
coast. Model ensemble clusters continue to show poor consensus on
the upper level pattern towards the rest of the next week. However,
CPC outlooks suggest a lean towards temperatures above seasonal
averages and precipitation below seasonal averages into the first
several days of October.

&&

.AVIATION...
(00Z TAFS)
Issued at 454 PM PDT Fri Sep 20 2024

Currently VFR everywhere except the Monterey Bay terminals of MRY
and SNS which are enveloped in ceilings. Largely a persistence
forecast as the marine layer is similar to what it was 24 hours ago
at 2,000 feet and is expected to remain in that range through the
TAF period. High confidence in the blanket of stratus offshore
filtering inland, impacting all terminals tonight in the form of
ceilings with the exception of LVK which is expected to remain VFR.
Widespread VFR will prevail by tomorrow afternoon.

Vicinity of SFO...Currently VFR with west-northwesterly flow.
High confidence in a ceiling impacting the terminal overnight and
through most of the morning tomorrow, the ceiling will be on the
MVFR/IFR cusp.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently IFR with westerly flow at MRY and
MVFR with northwesterly flow at SNS. High confidence in SNS further
deteriorating to IFR early this evening with both terminals
becoming VFR by tomorrow afternoon.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 838 PM PDT Fri Sep 20 2024

Northwesterly breezes will be gentle to moderate, with strong
gusts over the outer waters. Seas will be moderate, continuing to
build and remain rough in the outer waters. Winds decrease and
seas abate beginning Tuesday.

&&

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

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Sarment
MARINE...Sarment

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