000
FXUS66 KMTR 281725
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1025 AM PDT Sun May 28 2023

...New AVIATION...

.SYNOPSIS...
Issued at 300 AM PDT Sun May 28 2023

Weather conditions largely remain unchanged with unseasonably
cool temperatures to persist into the upcoming week. Widespread
night and morning low clouds will give way to inland clearing each
afternoon. The longer range outlook shows this pattern will
likely persist into early June.

&&

.SHORT TERM...
(Today and tonight)
Issued at 300 AM PDT Sun May 28 2023

A mid/upper level cut-off low pressure system currently off of
the northern California coast will continue to drop southward
during the next 24 hours. As such, mid-to-high level clouds can be
seen on satellite this morning above the widespread stratus which
has penetrated well inland. This feature aloft has allowed for
the marine layer to compress slightly resulting in more widespread
drizzle this morning, especially near the coast and in the
favored moist upslope regions of the North Bay and East Bay.
Clouds will be slower to clear this afternoon given the mid/upper
level feature aloft. This system will also support a low
probability (10-20%) for isolated showers and/or thunderstorms
over far northern Sonoma and Napa counties, however limited
daytime heating in response to cloud cover will hinder
development. For tonight, more of the same with the return of low
clouds and patchy drizzle.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 300 AM PDT Sun May 28 2023

The aforementioned upper level low will linger off of the central
and southern California coast into early next week. As a result,
expecting more of the same under the influence of troughing. Thus,
temperatures will largely remain below seasonal averages with
widespread night and morning low clouds. Patchy drizzle is also
expected to persist in this pattern as it has for the past week or
so. There are some hints of slight warming late in the upcoming
week as the closed low shifts inland. However, a general troughing
pattern will persist off of the West Coast into early June.

&&

.AVIATION...
(18Z TAFS)
Issued at 1024 AM PDT Sun May 28 2023

High clouds streaming across the area this morning as a weak cold
front aloft associated with a low pressure over north-central CA
pushes through, evident via the 12Z sounding. Radar showing very
light isolated showers, though any impacts to terminals should be
limited to brief DZ if any. High clouds contributing to some
uncertainty regarding the clearing of low clouds. Low confidence
(~20%) in clearing to VFR for Bay Area terminals. Ultimately will
need to see how the stratus deck starts to respond once high
clouds move away. Otherwise breezy onshore flow this afternoon.
There is also a low probability (10-20%) of some CB north of
KSTS/KAPC this afternoon during peak heating, though any deep
convective development will very likely be limited by the marine
layer.

Vicinity of SFO...Low confidence (~20%) in clearing to VFR during
the 21-00Z timeframe. Otherwise expecting MVFR cigs through the day
today and into Monday morning. As previously mentioned, will need to
see how low clouds respond to mid/high clouds moving out late this
morning before increasing any confidence in clearing. Breezy to
gusty onshore winds 15-20 kts this afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay...Moderate confidence (50-60%) in MVFR/IFR cigs through
the TAF period.  Cigs lowering to widespread IFR by the early
morning hours Monday due to marine layer compressing slightly in the
subsidence regime behind the upper low. Otherwise breezy onshore
this afternoon.

&&

.MARINE...
(Today through Friday)
Issued at 300 AM PDT Sun May 28 2023

Moderate northwest winds continue through Memorial Day with the
strongest winds over the northern outer waters. Breezy to gusty
westerly winds are also expected across the San Francisco Bay,
San Pablo Bay, Suisun Bay, and the Delta each afternoon. Longer
period background southerly swell continues through late next
week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 PM PDT this afternoon for PZZ540.

     Small Craft Advisory until 9 PM PDT this evening for PZZ570.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Behringer
MARINE...RGass

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NWS MTR Office Area Forecast Discussion

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print "<p>Low Temperature<br/><br/>$usalow</p>\n";
print "<p>High Precipatation<br/><br/>$usaprecip</p>\n";
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USA Extremes for Saturday, May 27, 2023

High Temperature

129°F at Immokalee Fl, FL

Low Temperature

25°F at Mineral Point Iowa County Ap, WI

High Precipatation

2.52in at Hinesville Ft Stewart, GA

Data courtesy of NWS-CPC

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