955
FXUS66 KMTR 222154
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
254 PM PDT Thu May 22 2025

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

.SYNOPSIS...
Issued at 252 PM PDT Thu May 22 2025

Elevated fire weather conditions continue through this evening due
to the combination of warm, dry, and windy conditions across the
region. Fire weather concerns ease by Friday morning with
pleasant, below normal temperatures and diurnally breezy winds to
continue into next week.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 252 PM PDT Thu May 22 2025

Strong onshore winds gusting between 30 to 35 mph along the coast,
mountain gaps and passes, and northwest/southeast oriented valleys
continue overnight into Friday morning. Elevated fire weather
concerns persists through this evening with dry conditions across
the interior (relative humidity values in the 15 to 30% range). The
primary concern continues to be for areas where grasses are cured
(grasses have browned/dried out). An approaching upper level trough
will help to bring in more moist air and deepen the marine layer to
1500 ft tonight. This increase in moisture will ease the elevated
fire concerns that we have seen over the last few days with
overnight relative humidity values increasing to 70-90% across the
interior.  Patchy stratus cover will return to coastal areas and the
San Francisco Bay region overnight but is not expected to be
widespread. Breezy winds will continue again on Friday, but, they
will be weaker than those observed on Wednesday/Thursday. Winds are
expected to gust between 20-25 mph on Friday along the coast,
through the valleys, and across the elevated terrain. Temperatures
across the North Bay hold steady in the upper 70s on Friday while
temperatures across the rest of the Bay Area will drop by about 5
degrees. This will bring most locations across the South Bay and
East Bay into the upper 60s to mid 70s and into the 50s to 60s along
the San Francisco Peninsula. Residents of the interior Central Coast
may feel a more substantial drop, with highs to drop from the upper
80s to low 90s on Thursday to the low to mid 80s on Friday. If you
find yourself thinking that this is a bit chilly for May, you would
be correct in that Friday`s forecast temperatures are expected to be
around 10 degrees below normal for this time of year.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 252 PM PDT Thu May 22 2025

Surface high pressure and a positively tilted upper level trough
will build in over the weekend into next week over the West Coast.
This will help to keep our temperatures and winds in a fairly stable
pattern this week. For temperatures, highs will stay in the 70s to
low 80s across the interior and upper 50s to mid 60s along the
coastline. Diurnally breezy winds between 20 to 30 mph will continue
across the coastline, valleys, and across the elevated terrain
through Wednesday. Overall this upcoming week looks pleasant with
temperatures running around 10 degrees below normal. That will
change by late next week with temperatures looking to rise again and
CPC forecasting above normal temperatures from the end of May into
June. In the longer run, both the GFS and ECMWF are starting to
generate a cut-off low oriented offshore to the southwest of the
California coastline. While this is still a ways out, it may be
worth keeping an eye on for the possibility of offshore winds across
the CWA.

&&

.AVIATION...
(18Z TAFS)
Issued at 1125 AM PDT Thu May 22 2025

Primarily VFR through the TAF period with patchy periods of MVFR-IFR
stratus in the San Francisco Bay and Monterey Bay region. Winds
strengthen during the day with gusts between 20 to 32 knots across
portions of the Bay Area and Central Coast. Winds ease overnight
before locally breezy conditions develop during the day again
tomorrow. Confidence is low that fog will develop across the North
Bay Valleys tonight with conditions looking to be too dry for fog
development.

Vicinity of SFO...VFR becoming IFR overnight. Patchy IFR stratus
will develop overnight around 10Z before dissipating by mid Friday
morning. Strong winds gusting up to 32 knots are expected this
afternoon before easing overnight to around 12 knots. Gusty winds up
to 27 knots will return during the day on Friday.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR becoming MVFR overnight. MVFR CIGs look
to return tomorrow morning around 13Z and persist through late
tomorrow morning. CIGs are borderline MVFR/IFR with some potential
for IFR CIGs to develop overnight. Breezy onshore winds continue
through the TAF period with lighter, more variable winds expected
overnight.

&&

.MARINE...
(Today through Tuesday)
Issued at 926 AM PDT Thu May 22 2025

Widespread hazardous marine conditions continue today as strong
northwesterly breezes with near gale to gale force gusts and rough
seas persist. Fresh to strong northwesterly breezes and moderate
to  rough seas will prevail Friday through Monday.

&&

.FIRE WEATHER...
Issued at 238 AM PDT Thu May 22 2025

The combination of poor daytime relative humidity of 15-25% and
onshore winds with gusts of 25-35 mph along the immediate coastline,
in northwest/southeast oriented valleys, and in the higher terrain
will continue to support elevated fire weather conditions today. The
greatest period of concern is today in cured grass areas. Remain
fire wise and do not be the reason for fire starts.

Sarment

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Friday for SF Bay N of Bay
     Bridge.

     Small Craft Advisory from 3 PM to 9 PM PDT Friday for SF Bay N
     of Bay Bridge.

     Gale Warning until 3 AM PDT Friday for Mry Bay-Pigeon Pt to Pt
     Pinos 0-10 nm.

     Small Craft Advisory until 9 AM PDT Friday for Pt Arena to Pt
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning from 9 AM Friday to 3 AM PDT Saturday for Pt Arena
     to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory until 3 PM PDT Friday for Pt Reyes to
     Pigeon Pt 0-10 nm.

     Gale Warning from 3 PM Friday to 3 AM PDT Saturday for Pt Reyes
     to Pigeon Pt 0-10 nm.

     Gale Warning until 3 AM PDT Saturday for Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

     Small Craft Advisory until 3 AM PDT Saturday for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...Murdock
MARINE...Murdock

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NWS MTR Office Area Forecast Discussion