052
FXUS66 KMTR 170416
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
916 PM PDT Thu May 16 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 1227 PM PDT Thu May 16 2024

Quiet weather continues with a persistent marine layer through the
weekend. Calm and cloudy mornings will transition to breezy and
clear afternoons. A weak cold front will move through next week,
bringing stronger westerly winds and cooler inland temperatures.

&&

.UPDATE...
Issued at 855 PM PDT Thu May 16 2024

Stratus quo this evening across the Bay Area and Central Coast.
Profilers put the marine layer around 2000 feet and the Oakland
sounding agrees with the depth around 2100 feet. A quick check of
pressure gradients around the region shows the onshore gradient
has weakened since yesterday, but regardless it`s still over 3mb.
Latest satellite fog product shows the persistent onshore flow is
allow the marine layer to make it`s nightly march inland. Current
forecast remains on track for tonight. As noted below, in addition
to clouds patchy drizzle will once again be possible. Hi-res model
guidance generates a few hundredths along the coast, which is
usually a sign of coastal drizzle.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 1227 PM PDT Thu May 16 2024

Stratus is continuing to clear. SW flow is delaying the clearing
in Santa Cruz, Marin, and Sonoma counties, but there should be a
few hours of sunshine before the next round of clouds develop this
evening. The marine layer is quite deep, with the Ft. Ord profiler
showing marine air from the surface to roughly 2,200 ft. This is
quite a bit deeper than models suggest, which has led to some
issues with the forecast. Not only are the deeper clouds
penetrating further inland than expected, some of the thicker
cloud decks have been producing measurable drizzle and light rain
in Monterey, Santa Cruz and Napa counties early this morning. The
forecast was adjusted to show a 15% chance of rain and 0.01" QPF
for these areas tomorrow, as there is no synoptic reason for the
marine layer to compress very much.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 1227 PM PDT Thu May 16 2024

The same pattern will continue through the weekend with cloudy
mornings and clear afternoons. The jet stream will take a dip
south next week, causing a transition to a troughing pattern early
next week. This pattern looks to persist through the week and will
bring a few weak cold fronts, cooler temperatures, and breezy NW
winds. Coastal drizzle may become a bit more prominent at times as
well. High temperatures will reamin in the 60s along the coast,
but will cool to the 70s inland.

&&

.AVIATION...
(00Z TAFS)
Issued at 430 PM PDT Thu May 16 2024

Relatively light westerly surface winds will continue across our
area, with the onshore flow producing another night of MVFR/IFR
stratus ceilings persisting through the late morning hours on
Friday, with mostly VFR expected Friday afternoon.

Vicinity of SFO...VFR conditions currently will eventually give
way to MVFR/IFR with low stratus clouds gradually moving inland over
the terminal by late this afternoon and early evening tonight and
persisting through the overnight hours into late morning
tomorrow. Clouds will clear by early afternoon Friday with VFR
through the remainder of the TAF period.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Current VFR conditions will drop to IFR
later this evening as the marine boundary stratus moves inland
with relatively light westerly surface winds persisting through
the forecast period.

&&

.MARINE...
(Tonight through next Wednesday)
Issued at 855 PM PDT Thu May 16 2024

A surface high over the Eastern Pacific continues to move
eastward towards California. Northwesterly winds are strengthening
as a result, particularly over the northernmost zones and outer
waters. Seas will build to very rough over the outer waters
through the early part of next week.

&&

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

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...JM
MARINE...DialH

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea