636
FXUS66 KMTR 252100
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
200 PM PDT Wed Jun 25 2025
...New SYNOPSIS, SHORT TERM, LONG TERM...
.SYNOPSIS...
Issued at 200 PM PDT Wed Jun 25 2025
A seasonal late June weather pattern continues into Thursday with
a well established marine layer along the coast, spreading low
clouds and fog inland night and morning hours. Temperatures
running near or slightly below normal inland but forecast to warm
into the 90s for some of the interior valleys Friday and
Saturday. A weak upper low off the coast Sunday through early next
week will keep onshore flow and seasonal temperatures in place.
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 200 PM PDT Wed Jun 25 2025
For the most part low clouds have cleared back to the coast with
only the usual dreary spots such as Pt Reyes, Ocean Beach and the
Monterey Peninsula holding onto low clouds with continued
northwesterly onshore winds. Temperatures are ranging from the
upper 50s SF/Half Moon Bay to 60/70s around the bay and 80s inland
with plenty of sunshine this afternoon. However no real hot
weather to speak of with only lower 90s for interior Monterey
county. The marine layer looks to be around 1800 feet and should
spread inland once again this evening and overnight.
&&
.LONG TERM...
(Thursday night through next Tuesday)
Issued at 1254 PM PDT Wed Jun 25 2025
An inland warming trend should occur on Friday as 850 mb temps
warm to around 21-22 celsius. Places like Livermore and Concord
should warm into the low/mid 90s with some local northerly winds
off Mt Saint Helena helping Santa Rosa with a quick uptick in high
temps for Friday afternoon. Still expect the marine layer to hold
steady along the coast keeping the coast and bays mild. Interior
temps stay in the lower/mid 90s Saturday with no big changes in
the synoptic pattern.
By Sunday a weak low off the coast will induce some southerly
winds that will bring cooler conditions to the North Bay valleys
and the interior highs will likely drop in the upper 80s (vs 90s)
except interior Monterey county. The upper low will likely
lift/deepen the marine layer on Sunday with some morning drizzle.
That feature may induce enough lift and divergent flow over
Northeast California to induce afternoon convection but that would
be outside of our area perhaps as close as the coastal mountains
in Mendocino county and points northward. Long range forecast
uncertainty will deal with how that weak upper circulation
evolves. The deterministic ECMWF cuts the feature off as a weak
cut-off low west of the Central Coast that would keep temps near
or slightly below normal for the first week of July and into the
July 4th holiday weekend. Model consensus at this time shows no
big heat dome over the west and any monsoon moisture staying
confined to the Southern Sierra and deserts of SoCal through the
holiday weekend.
&&
.AVIATION...
(18Z TAFS)
Issued at 1036 AM PDT Wed Jun 25 2025
Currently a mix of IFR to MVFR conditions across much of the region,
while inland areas have either scattered or completely cleared out.
Conditions will continue to improve through late morning with most
sites forecast to return to VFR between 18-20Z with increasing
onshore winds. However, HAF may maintain IFR to MVFR conditions
throughout the TAF period. Low to moderate confidence for IFR to
MVFR conditions to return to the Bay Area terminals early Thursday
morning. The HRRR does not show any low ceilings impacting the
region during the overnight hours and into Thursday morning, yet
other guidance suggests they return around or after 07Z Thursday.
Meanwhile, greater confidence for the Monterey Bay terminals
returning to LIFR to MVFR around 03Z Thursday. Winds increase once
again Thursday afternoon with just about all sites returning to VFR
conditions.
Vicinity of SFO...VFR. Winds increase this afternoon with gusts up
to or greater than 25 KT. Winds ease a bit overnight and into
Thursday morning with low to moderate confidence for IFR to MVFR
conditions returning. Any low clouds that do happen to develop will
clear out by around 17Z Thursday with onshore winds once again
expected to increase.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Tricky forecast this morning with IFR
conditions prevailing at MRY while SNS is likely to clear out by 18Z
today. To believe MRY will scatter out around 19Z with an early
return around 03Z Thursday at both sites. Onshore winds increase
this afternoon before easing overnight and into early Thursday
morning. Moderate to high confidence.
&&
.MARINE...
(Today through Monday)
Issued at 1036 AM PDT Wed Jun 25 2025
Fresh to strong northwesterly breezes with near-gale force gusts
will prevail through the week. Gale force gusts can be expected
near the coastal jet regions of Point Reyes and Point Sur on
Wednesday and Thursday afternoons. Moderate to rough seas will
prevail through the week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory from 9 PM this evening to 2 AM PDT
Thursday for CAZ006-506-508.
PZ...Small Craft Advisory from 9 AM to 9 PM PDT Thursday for Mry Bay.
Small Craft Advisory until 9 AM PDT Thursday for Pt Arena to Pt
Reyes 0-10 nm.
Gale Warning from 9 AM to 9 PM PDT Thursday for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt
Pinos 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
to Pt Pinos 0-10 nm.
Small Craft Advisory from 9 AM Thursday to 3 AM PDT Friday for
Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory until 3 PM PDT Thursday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Gale Warning from 3 PM Thursday to 3 AM PDT Friday for Pt Pinos
to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...RW
LONG TERM....RW
AVIATION...RGass
MARINE...RGass
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