Area Forecast Discussion Issued by NWS San Francisco Bay Area, CA
000
FXUS66 KMTR 300534
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1034 PM PDT Mon May 29 2023
...New AVIATION, MARINE...
.SYNOPSIS...
Issued at 143 PM PDT Mon May 29 2023
Temperatures continue to look to be on the below normal side over
the next few days as continued troughing dampens any chance at
warming up until the weekend. Stratus will continue to be present
at coastal areas through the nights and early morning, before
clearing later in the day. A slight warm-up expected late in the
week.
&&
.UPDATE...
Issued at 750 PM PDT Mon May 29 2023
Not much in the ways of active weather this evening. Outside of
our forecast area, however, portions of the Sierra and northern
coastal ranges had some thunderstorm activity earlier this
evening. The Central Coast and Bay Area region did not have the
instability to support tstorm activity, but we did have stratus!
Because of lingering stratus over Sonoma County today, one of the
coldest spots was Santa Rosa with a high of 61. Elsewhere,
temperatures this afternoon peaked in the mid to upper 60s to low
70s. Low clouds and drizzle along favored coastal terrain will
again be the story tonight into Tuesday morning. No forecast
updates needed at this time.
&&
.SHORT TERM...
(This evening through Wednesday) Issued at 143 PM PDT Mon May 29
2023
A glance at satellite imagery this afternoon shows stratus
lingering in the North Bay, near Santa Rosa and
Petaluma, and Monterey Bay region. Elsewhere, the stratus has
mixed out, lending to mostly clear skies. The cutoff low that has
pestered the region the last few days continues to hang around,
but has made its way far enough south to be sitting off the
Monterey/ San Louis Obispo county coast. As it does so, it will
continue to keep temperatures cool and below normal, similar to
what we`ve seen the past few days. It is not until mid to later
week that it is expected to exit off to the southeast.
That being said, continue to expect high temperatures near the
coast to remain in the upper 50s to mid 60s, with inland regions
reaching closer to low 70s. Low temperatures range from the upper
40s to low 50s. Near the coast, the stratus is expected to
continue in the same pattern we have seen: robust and extending
inland overnight, then generally clearing and mixing out in the
late afternoon. Drizzle remains a possibility closest to the Big
Sur coast.
&&
.LONG TERM...
(Thursday through Sunday) Issued at 143 PM PDT Mon May 29 2023
Towards the end of the week, in the Thursday and Friday time
range, models seem to be in better agreement as to temperatures
gradually beginning to warm up as slight ridging begins to build
in. Ridging looks to be most amplified Saturday, lending to the
warmest temperatures of the week, bringing them closer to averages
for this time of year. However, another low looks to move in
beyond this, helping to break down the ridge and reduce
temperatures again to below-normal for the first portion of June.
Current CPC outlooks concur, placing much of the region under
below-normal temperatures through at least the next fourteen days.
&&
.AVIATION...
(06Z TAFS)
Issued at 1033 PM PDT Mon May 29 2023
Nighttime satellite imagery shows a mix of high clouds and low level
clouds. Unfortunately this makes it difficult to see how the low
clouds are progressing inland. Based on observations, mix of VFR and
MVFR conditions prevail with KSTS, KMRY, and KSNS currently under
MVFR conditions. MVFR conditions expected to become more
widespread, moving inland to more terminals as as deep marine
layer persists. Timing of arrival is still of low to moderate
confidence with weaker onshore gradient and upper level low all at
play. Higher confidence exists for later stratus arrival (after
10z), where there is most model agreement. However, cannot rule
out an earlier arrival of stratus. Will continue to monitor.
Stratus clearing time expected around 17-18z.
Vicinity of SFO...FEW low clouds around 2500 feet with diminished SW
winds currently. Pushed back timing of arrival for MVFR cigs even
later for 06z tafs based on current guidance, but confidence is
still low to moderate. If stratus does move over terminal after 10-
11z, cigs will last through 18z. lasting through 18z. VFR expected
Tuesday late morning with WSW winds becoming breezy in the
afternoon with gusts up to 20 knots.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR at KSNS and KMRY expected to
continue through the night. VFR expected after 18z with onshore
flow around 8 to 15 knots returning in the afternoon Tuesday.
&&
.MARINE...
(Tonight through next Saturday)
Issued at 1033 PM PDT Mon May 29 2023
Light southerly winds continue through the night, turning
northwesterly Tuesday morning for the northern waters, afternoon
for the southern waters, as a low moves ashore. Increasing winds
through midweek create steeper wind driven waves. Light
northwesterly swell around 14 to 16 seconds persists through
midweek.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
UPDATE...McCorkle
SHORT TERM...AC
LONG TERM....AC
AVIATION...McCorkle/DialH
MARINE...DialH
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