San Pablo, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

329
FXUS66 KMTR 271742
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1042 AM PDT Tue May 27 2025

...New AVIATION...

.SYNOPSIS...
Issued at 245 AM PDT Tue May 27 2025

Seasonable conditions through Wednesday. Moderate HeatRisk and
elevated fire weather conditions return by Thursday. Cooler
weather returns late next weekend.

&&

.UPDATE...
Issued at 1029 AM PDT Tue May 27 2025

The short term forecast remains in good shape and we`ll continue
to monitor the potential for heat impacts as we get toward the end
of the week. Otherwise, marine stratus continues to erode this
morning and it should be a largely pleasant day. Spring Tides
should are still forecast to result in minor coastal flooding
along portions of the San Francisco Bay Area late tonight and into
the pre-dawn hours on Wednesday.

&&

.SHORT TERM...
Issued at 244 AM PDT Tue May 27 2025
(Today and tonight)

Key Points
-Coastal Flood Advisory was re-issued for Tuesday night

First and foremost the Coastal Flood Advisory was re-issued again
for the Bay Shoreline tonight into Wednesday morning. While not as
impactful as a King Tide, this perigean spring tide will bring
minor coastal/bay shoreline flooding. In other words, nuisance
flooding with impacts mainly for the lowest lying locations.

Interesting longwave pattern being resolved by model guidance
over the West this morning. The most notable features aloft are:
upper low over Gulf of AK with broad trough to the south, embedded
shortwave trough rounding the base of the broad trough, weak low
pressure over interior CA, and shortwave ridging over the Bay Area
and Central Coast. So what does this all mean for sensible weather
today? Seasonable weather with a summer like marine layer.
Satellite fog product shows a more organized marine layer than 24
hours. Coastal marine layer clouds exist from Golden Gate
southward with inland push through Monterey Bay, Hollister, and
Salinas Valley. Patchy clouds are also developing inside SF Bay
and N Bay Valleys. Depth of the marine layer per profiler is close
to 2k feet. Some mist or very patchy drizzle possible this
morning along the immediate coast. Do expect morning clouds to
roll back to the coast by afternoon. Inland sunshine will yield
temps in the 70s and 80s...cooler at the coast and in the upper
50s to near 70.

For tonight - shortwave ridge flattens as the upstream embedded
shortwave approaches from the west. Marine layer deepens a tad
and moves farther inland.

Additional Note - No Oakland Sounding this morning due to
equipment issues.

&&

.LONG TERM...
Issued at 344 AM PDT Tue May 27 2025
(Wednesday through Monday)

Key Points
-Breezy to Gusty NW winds Wednesday into Thursday
-Elevated fire weather concerns late week
-Moderate HeatRisk Friday with interior heat
-Upper level moisture streams in from the S next weekend as cooler
 weather returns

500mb heights and 850mb temps take a hit Wednesday as the upstream
shortwave trough becomes a cut-off low near SoCal. Additionally,
the broad upper trough moves through the PacNW. Temperatures
moderate on Wednesday with the dynamic upper level pattern.
Additionally, stronger onshore flow and breezy/gusty NW winds
over the coastal waters will keep temperatures in check. Winds
are not strong enough to warrant a Wind Advisory.

By Thursday, a strong area of high pressure currently well off
the SoCal coast will strengthen and build northward over the Bay
Area and Central Coast. This will kick off a noticeable warming
and drying trend across the state. A solid 5 to 8 degree jump in
temperatures from Wednesday to Thursday as a result of the change
pattern. Further warming is expected by Friday as the peak of the
ridge/850mb temps are centered over the forecast area with an
additional 5-10 degree jump. With 850mb temps predicted to be
around 25C that would put max temp potential over 100 degrees.
Current forecast does show max temp in the upper 90s to 106
across the interior. Did nudge temperatures upwards for interior
locations Friday. That now puts more areas in the Moderate
HeatRisk with a few pockets of Major HeatRisk. At this point, it
looks like interior areas will need a Heat Advisory at a minimum
for Friday. For some locations this will be the hottest
temperatures of the year. Thankfully, lack off stronger offshore
flow will keep coastal areas in check. However, they`ll still be
warm, but not in an impactful way with max temps in the upper 60s
to mid 80s. Temperatures ease a little on Saturday by a few
degrees, but still plenty warm across the interior. More
widespread cooling is expected by Sunday and Monday as the ridge
breaks down as another trough sweeps through NorCal and the PacNW.

Fire Weather: given the expected warm up for the second half of
the week elevated fire weather concerns also develop.
Temperatures go up and humidity values are expected to drop, both
day and night. In fact, some guidance shows a few bursts of
offshore flow over the higher terrain. This set up doesn`t
warrant a Red Flag warning, but stronger wording seems right.
Hot, dry, and occasionally offshore/breezy will further dry out
fuels. There has been an uptick in grass fires and could see more
later this week.

Lastly, something we`ll need to keep a close eye next weekend as
the ridge breaks down will be moisture streaming in from SoCal.
As the cut-off low near SoCal wobbles northward on and an upper
level trough moves in from the west a pulse of high PWAT gets
pushed north into the Central Coast. Still very far out, but
there is marginal MUCAPE and higher lapse rates. Not saying
thunderstorms yet, but will need to fine tune this over the next
few days.

&&

.AVIATION...
(18Z TAFS)
Issued at 1040 AM PDT Tue May 27 2025

VFR conditions are returning to the region with the exception being
KHAF where IFR/MVFR conditions are likely to persist through much of
the forecast period. Onshore winds will once again increase by early
afternoon across most TAF sites and begin to diminish as we head
into the night and early Wednesday morning. Now let`s talk about
ceilings! There is high confidence low clouds will return to the Bay
Area region early Wednesday morning, generally in the MVFR/IFR
range. However, the Monterey Bay terminals have high confidence in
an early return of MVFR/IFR ceilings by late this afternoon or early
evening and lowering to LIFR by Wednesday morning. Conditions will
gradually improve to VFR Wednesday afternoon with an increase once
again of onshore flow.

Vicinity of SFO...Onshore winds are forecast to increase this
afternoon from the west/northwest to around 14 kt, yet cannot rule
out a few higher gusts. Winds will ease into Wednesday morning with
high confidence of MVFR/IFR ceilings to develop. Low ceilings will
persist through around 19Z Wednesday before dissipating thereafter.
VFR conditions and onshore winds will once again increase Wednesday
afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Onshore winds increase once again this
afternoon, but generally remain below 14 kt. Winds ease late this
evening and into Wednesday morning. High confidence for an early
return of MVFR/IFR ceilings by late this afternoon or early evening
before lowering to LIFR by Wednesday morning.

&&

.MARINE...
(Today through Sunday)
Issued at 1029 AM PDT Tue May 27 2025

Northwest winds will mainly ease over the coastal waters through
Tuesday night. Northwest winds will increase again Wednesday with
gale force gusts developing over the southern inner coastal
waters later Wednesday. Stronger winds during the midweek will
lead to hazardous conditions for small craft due to steep wind
waves.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory from 10 PM this evening to 2 AM PDT
     Wednesday for CAZ006-506-508.

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 to 9 PM PDT Wednesday for Mry Bay-
     Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60
     NM-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

     Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Pt
     Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

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

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

     Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 10-60 NM.

&&

$$

UPDATE...Bain
SHORT TERM...MM
LONG TERM....MM
AVIATION...RGass
MARINE...RGass

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