Santa Clara, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

556
FXUS66 KMTR 230022
AFDMTR

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

...New AVIATION...

.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...
(00Z TAFS)
Issued at 521 PM PDT Thu May 22 2025

Fairly quiet conditions across the region with breezy west to
northwest winds being observed. Expect winds to gradually weaken
through the evening, with the forecast challenge becoming stratus
and fog. Felt the inherited TAFs were in good shape, with North Bay
sites likely remaining VFR. There are some weak signals of reduced
vis and/or cig at KSTS but confidence was too low to introduce any
hints of that. As you head south, stratus is expected to build
around the coast around KHAF and then snake into KSFO and KOAK and
place cigs between IFR and MVFR status. KLVK and KSJC remain VFR.
Stratus is expected along the Central Coast as well later tonight.
Cigs lift by mid to late morning tomorrow, and while winds increase
once again for the afternoon.


Vicinity of SFO...The forecast is on track this evening, with gusty
westerly winds around 30 to 34kt are being observed. Expect winds to
gradually weaken through the evening. Stratus is expected to develop
later this evening and potentially bring IFR stratus to KSFO around
or after 9Z. Stratus should clear by late morning, with gusty
westerly winds returning shortly after that or by the early
afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Winds remain a bit breezy, with gusts
around 20kt, the Monterey Bay region this afternoon. VFR conditions
currently prevail, but are expected to give way to IFR to MVFR
conditions late tonight or early tomorrow morning. Latest guidance
has cigs clearing by early afternoon, which should bring a stint of
VFR conditions until tomorrow evening.

&&

.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...KR
MARINE...Murdock

Visit us at www.weather.gov/sanfrancisco

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