Chualar, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

369
FXUS66 KMTR 281137
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
437 AM PDT Wed May 28 2025

...New AVIATION...

.SYNOPSIS...
Issued at 253 AM PDT Wed May 28 2025

Near normal temperatures are anticipated through mid-week with
impactful heat by Friday. The fire weather threat will elevate
through the end of the week. Thereafter, temperatures are expected
to return to near normal values.

&&

.SHORT TERM...
Issued at 253 AM PDT Wed May 28 2025
(Today and tonight)

Key Messages
-May Gray with coastal drizzle
-Seasonable temperatures
-Stronger onshore winds

May Gray alert in effect this morning. Overnight satellite fog
product shows a very well defined marine layer hugging the coast
and pushing well inland. Coastal profilers put the depth
1,500-1,700 feet. Given the very moist low levels added drizzle to
the forecast mainly for coastal areas this morning. Patchy fog
will also be possible along the immediate coast. It will take some
time, but inland areas will see the marine layer roll back to the
coast. The slow erosion will be due to a decent onshore gradient
(SFO-SAC) greater than 4mb. Coastal areas on the other hand will
struggle to see much in the way of sunshine this afternoon. As
such, definitely a temperature contrast today from the coast to
inland locations - Upper 50s to near 70s coast and 70s to upper
80s inland. The marine layer will push inland again tonight with
a similar depth and coverage. Coastal drizzle/patchy fog will be
possible once again. Not only does the marine layer provide a temp
contrast, but also a humidity contrast in the vertical. Higher
elevations will remain on the drier with moderate to poor humidity
recovery.

Lastly, the increasing onshore gradient will result in stronger
winds this afternoon and overnight. Winds will be strongest over
the coastal waters, immediate coast, and inland gaps/passes. Not
strong enough for a wind advisory, but gusts 30-40 mph seems
plausible.

&&

.LONG TERM...
Issued at 353 AM PDT Wed May 28 2025
(Thursday through Tuesday)

Key Messages
-Above normal temperatures through Saturday
-Impactful heat Friday with Heat Advisory - Santa Cruz Mts added
-Cool down Sunday and early next week

An upper level ridge will build across the Bay Area Thursday. The
orientation of the ridge (SW to NE) is being squeezed by a cut-
off low near Baja and an upper trough near Gulf of AK. This upper
ridge will peak Friday before weakening over the weekend. The
airmass associated with the ridge is rather toasty with 850mb
temps reaching the mid 20C, which is 5-10 degrees above normal.
Under a fully mixed atmosphere or no marine influence those values
would yield max temperatures over 100 degrees. That`s what the
forecast has for far interior locations on Friday, 100-105 degrees
for a max temp. Other inland locations will also feature above
normal temps with highs in the upper 80s to upper 90s. HeatRisk
values remain in the "moderate" category with pockets of "major".
With this forecast update decided to include the Santa Cruz Mts
for the Heat Advisory on Friday. Places like Boulder Creek and Ben
Lomond will be in the upper 90s. The ridge begins to weaken by
Saturday with cooler temperatures developing. Saturday will be a
transition day with more widespread cooling expected by Sunday. As
such, interior N and E Bay, and interior Central Coast may need
one additional day of a Heat Advisory, but will hold off for now.
Not expecting this to be a record breaking heat event, but some of
the hottest temperatures of the year for some locations. Heat
safety protocols should be followed for those with outdoor plans
and/or those sensitive to heat Thursday through Saturday.
Temperatures finally return to seasonal averages by Sunday and
below seasonal averages by early next week.

As noted on the last two forecast discussions one low chance high
impact scenario we continue to monitor closely will be high-based
convection Saturday potential over the Central Coast. Longer
range model guidance continues to advertise a northward push of
some upper level moisture. The cut-off low spinning over SoCal
will be the main driver of this moisture push. Given the
uncertainty that typically follows cut-off lows will not add any
convection to the forecast at this time. Best way to describe
this would be a non-zero chances.

&&

.AVIATION...
(12Z TAFS)
Issued at 437 AM PDT Wed May 28 2025

Coastal stratus along with patchy fog /MVFR-LIFR/ and onshore
winds prevail this morning. HREF output show it`ll be slow
clearing along the immediate coastline through morning, best
probability for VFR will be far inland locations and during the
afternoon closer to the coastline. Coastal stratus and fog will
move inland tonight and Thursday morning.

Vicinity of SFO...IFR stratus ceiling continuing to late morning,
then gradually lifting to MVFR to early afternoon based on recent
HREF and RAP model output. West wind increasing to 15 to 25 knots
late morning to mid evening today. Stratus /MVFR/ possibly IFR
ceiling returns tonight and Thursday morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR-LIFR in stratus continuing to late
morning, cloud ceilings gradually improving thereafter to MVFR-VFR
during the afternoon. Stratus /IFR/ returns tonight and Thursday
morning. West to northwest winds 5 to 15 knots.

&&

.MARINE...
(Today through Monday)
Issued at 253 AM PDT Wed May 28 2025

Northwest winds will increase over the coastal waters today with
gale force gusts developing over the southern inner coastal
waters. Strong and gusty northwest winds will continue to pose a
threat to small craft due to steep wind waves through much of the
forecast  period.

&&

.FIRE WEATHER...
Issued at 330 AM PDT Wed May 28 2025

Elevated fire weather concerns will develop and persist into the
weekend. Despite the marine layer bringing decent moisture to
lower elevations, higher elevations remain dry with moderate to
locally poor humidity recovery the next few days. As daytime
temperatures ramp up Thursday, peak Friday, moderate Saturday,
daytime minimum humidity will follow a similar path with low
values. Onshore flow will bring occasional gusty winds, but not
strong enough or widespread enough to warrant a Red Flag Warning.
Regardless people should be mindful with open flames, secure tow
chains, and avoid activities that could spark a grass fire. This
is particularly true given the slight uptick in vegetation fires
over the past couple of weeks.

As noted above, we continue to monitor a non-zero chance for
high-based convection on Saturday for the Central Coast. Concern
would be dry lightning on the heels of a hot and dry spell.

MM

&&

.CLIMATE...
Issued at 1128 PM PDT Tue May 27 2025

Record high temperatures at the long term climate stations Friday,
May 30th and Saturday, May 31st.

Station            May 30th            May 31st

Santa Rosa         100F 1910            99F 1970
Kentfield          101F 1950           102F 2001
Napa               104F 1910           103F 2001
Richmond            94F 2001, 1978      95F 2001
Livermore          108F 1910           104F 2001, 1910
San Francisco       91F 1978            90F 2001
SFO Airport         95F 2001            91F 2001
Redwood City       101F 1950            99F 2001
Half Moon Bay       67F 1978, 1941      77F 1997
Oakland downtown    98F 1978            89F 2001
San Jose           102F 1910            98F 1970
Salinas Airport     95F 2001            90F 1997
King City          102F 2001           100F 2001

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 11 AM to 8 PM PDT Friday for CAZ504-506-510-
     512>518-528.

PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for SF Bay N of Bay Bridge.

     Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
     Thursday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon
     Pt to Pt Pinos 10-60 NM.

     Small Craft Advisory from 9 AM to 9 PM PDT Thursday for Mry Bay-
     Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 3 AM PDT Friday
     for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60
     NM.

     Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Friday
     for Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 3 PM PDT this
     afternoon for Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Gale Warning from 3 PM this afternoon to 9 PM PDT Thursday for
     Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM Thursday to 3 AM PDT Friday for
     Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...Canepa
MARINE...Canepa

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