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000
FXUS66 KMTR 222157
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
257 PM PDT Mon Apr 22 2024

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

.SYNOPSIS...
Issued at 118 AM PDT Mon Apr 22 2024

Warm inland temperatures expected through today before cooler,
unsettled weather returns Tuesday and continues through late week.
Light rain chances for Thursday night and into Friday.

&&

.UPDATE...
Issued at 753 AM PDT Mon Apr 22 2024

Satellite shows a similar pattern to yesterday with the Monterey Bay
region blanketed in low level stratus and clear conditions
throughout the rest of the Bay Area. Marine layer heights are
similar to yesterday with heights around 1000-1200 feet. For the
Monterey Bay area, stratus looks to dissipate by mid to late
morning. Highs today will be in the mid 70`s to low 80`s inland in
the upper 50`s to lower 60`s along the coast. High temperatures
should run about 1-3 degrees cooler today than they were yesterday.
Today will be the last day with above normal temperatures this week
with below normal temperatures forecast tomorrow through the end of
the work week.

Rest of forecast looks on track with widespread stratus to return
later today and sharp drop in temperatures starting tomorrow.&&

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 256 PM PDT Mon Apr 22 2024

Primarily sunny across inland areas with clouds lingering along the
coastline and the Central Coast. Looking at satellite shows the
southerly surge of stratus in action with stratus extending
northwards from southern California to the North Bay coastline. As
of 2PM, inland temperatures are in the upper 60`s to low 80`s while
temperatures are in the low to mid 60`s along the coast. Widespread
stratus will move inland by late this evening/overnight throughout
the majority of the Bay Area. HREF guidance suggests that cloud
coverage will be patchier in nature throughout the Santa Clara
Valley. Monday night into Tuesday, orographic lifting will help to
generate light drizzle across coastal regions with precipitation
accumulations of a few hundredths of an inch expected.

An upper level disturbance will approach the coast beginning Tuesday
and lead to a pattern shift from above normal temperatures to below
normal temperatures. While Monday`s highs were 5 to 10 degrees above
normal, Tuesday`s highs are forecast to be, on average, 5 to 15
degrees below normal. High temperatures along the coast will linger
in the upper 50`s to low 60`s while highs inland will stay in the
60`s with a few areas potentially reaching the low 70`s.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 256 PM PDT Mon Apr 22 2024

Cooler, unsettled conditions will continue through Friday as an
upper level disturbance moves inland. High temperatures throughout
the work week will stay in the 60`s inland and in the upper 50`s to
low 60`s along the coastline. Low temperatures will stay in the mid
40`s to low 50`s with a few locations in mountainous terrain
dropping into the low 40`s. Guidance continues to indicate some
light precipitation is likely Thursday into Friday but confidence
remains mixed as to how much precipitation will actually occur. The
most recent run of the ECMWF shows light, scattered showers moving
over the Bay Area with amounts generally receiving less than 0.15 to
0.25 inches.

Temperatures will gradually start to rise and become closer to
normal towards the end of the weekend with highs returning to the
upper 60`s to low 70`s.

&&

.AVIATION...
(18Z TAFS)
Issued at 1048 AM PDT Mon Apr 22 2024

Mixed bag this morning with stratus impacting Monterey Bay
terminals and VFR elsewhere. Satellite imagery shows a southerly
surge pattern with stratus moving up the coast. The southerly
flow will also usher in stronger winds this afternoon and tonight.
Current taf package has higher winds than previous tafs,
especially for APC and OAK. Did fully buy in on SJC winds, but
some guidance has nearly 20kt SE prevailing winds Tuesday AM. Will
monitor this potential outcome. More widespread stratus tonight
and through the Tuesday AM rush. Didn`t put directly in the tafs,
but drizzle is possible Tuesday AM. Thinning of stratus will occur
most areas 17Z-18Z Tuesday.

Vicinity of SFO...VFR through early tonight. Impact near term
will be gusty SW with potential impact to runway config. Gusts to
20kt, but well short of any AWW criteria. MVFR cigs fill into SF
Bay 06-08Z Tuesday with cigs for SFO by 08Z through 16Z Tuesday.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR cigs continue to thin this AM around
Monterey Bay due to downslope flow from southerly surge. Expecting
VFR this afternoon. Cigs return early for SNS 00Z and then MRY
shortly after 02-04Z. MVFR cigs hold through 18Z Tuesday.

&&

.MARINE...
(Today through Sunday)
Issued at 1048 AM PDT Mon Apr 22 2024

Weakening high pressure to the north has led to weaker northerly
winds over the coastal waters today. Winds are locally strong over
the outer waters north of Point Reyes. Southerly flow will
gradually develop late this afternoon ahead of an approaching low
pressure system. Near Monterey Bay, winds this afternoon may gust
up to about 20 knots, but are expected to diminish into the
evening. Starting Wednesday, winds turn once more to become
moderate and northerly. Larger northwest swell abates through the
day today, with wave heights reducing to around 6 to 7 feet. Light
southerly swell continues to move through the waters this weekend
and through the upcoming work week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for SF Bay N of
     Bay Bridge.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...MM
MARINE...MM

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