FXUS66 KMTR 250423
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
923 PM PDT Wed Jun 24 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1200 PM PDT Wed Jun 24 2026
- Hazardous beach conditions along the Pacific Coast today
- An upper trough brings cooler temperatures, moisture, and a
deeper marine layer for Friday and Saturday
- Gusty onshore winds begin Thursday, peaking Friday and Saturday
with mountain passes gusting as high as 50-60 mph and marine
concerns through the weekend
&&
.SHORT TERM...
Issued at 1200 PM PDT Wed Jun 24 2026
(This evening through Thursday night)
As was the case yesterday, clouds have been slow to erode from
inland areas this morning with satellite showing many coastal areas
still socked in. Weak upper level ridging did compress the marine
layer a bit, preventing it from stretching as far inland as it did
Tuesday. Patchy fog was reported across multiple coastal sites this
morning but visibility is quickly improving as an eddy just off the
coast is helping to lift cloud bases. For areas that remain under
cloud cover, temperatures today won't see much change from Tuesday's
highs, generally remaining in the 70s and low 80s. For interior
areas, the weak ridging will be enough to push temperatures into the
upper 80s to low 90s today. Temps peak today with Minor HeatRisk
for those warmer spots before a slow cooling trend begins
Thursday.
The marine layer will remain relatively compressed tonight with
additional patchy fog and visibility impacts for coastal terrain
into Thursday morning. Upper level troughing will begin to push in
by Thursday morning, with heights slowly falling through the day.
This is likely to limit interior warming for Thursday afternoon,
with highs expected to be a few degrees cooler compared to today.
Around the same time, a large upper level low will sweep down the
Canadian coastline, tightening the gradient over California. Gusty
onshore winds will begin as early as Thursday, with the strongest
winds expected for Friday and the weekend. Marine impacts/details
from the uptick in winds can be found in the marine discussion below
and in the Small Craft Advisory.
The long-period southerly swell will continue to impact the Pacific
Coast beaches through this afternoon with a lull for the end of the
week. High rip current risk with sneaker waves...never turn your
back to the ocean! Additional beach hazards will be possible this
weekended, please see additional details in the discussion below.
&&
.LONG TERM...
Issued at 1200 PM PDT Wed Jun 24 2026
(Friday through next Tuesday)
A more significant cooldown will arrive Friday as heights continue
to fall with the approaching low to the north. A frontal passage
Friday could bring about 40-50+ mph winds for mountain passes and
wind-prone spots, and 30-35 mph winds for the coastal waters. Low
and mid-level moisture will surge in Friday as well, with a
deepening marine layer and 50%+ min RH for every location except the
very far interior spots. Drizzle and light rain will not be out of
the question for both Friday and Saturday mornings given a
sufficiently deep marine layer, and clouds may struggle to clear out
Friday afternoon. Fire weather concerns will also be limited despite
the strong winds given how high the humidity will be, along with
excellent overnight recovery into Saturday morning.
Saturday will be the coolest day of the forecast period with ample
moisture and a deep marine layer limiting daytime heating. Interior
spots may be limited to the low 70s with 60s for most other
locations and 50s right along the coast, around 10-15 degrees below
normal. Cooler weather and gusty onshore winds prevail into Sunday,
but the aforementioned low pivots northeastward and winds begin to
weaken by Sunday evening. With the lows true departure on Monday,
upper level ridging attempts to move back in but may face some
push back. Ensemble members continue to trend more in favor with a
troughing pattern prevailing into early week which would support
a minimal to slow warming trend compared to the cooler weekend.
&&
.AVIATION...
(06Z TAFS)
Issued at 923 PM PDT Wed Jun 24 2026
Onshore breezes will usher stratus /MVFR-IFR/ inland tonight and
Thursday morning. Stratus mixes out to the coastline with
conditions improving to MVFR-VFR by late Thursday morning and
afternoon. Coastal stratus redevelops Thursday night and Friday
morning.
Vicinity of SFO...Stratus /IFR/ prevails tonight and Thursday
morning with mix out to VFR 17z Thursday. Stratus /IFR/ returns
Thursday evening and night. West wind decreasing to near 10 knots
tonight and Thursday morning. West wind near 20 knots Thursday
afternoon to mid evening then decreasing to 10 knots.
SFO Bridge Approach...Similar to SFO.
Vicinity of SJC and OAK...For SJC Airport VFR for the evening,
then stratus /MVFR/ develops overnight then mixes out to VFR 17z
Thursday. Northwest wind near 10 knots decreasing to light and
variable wind Thursday morning then northwest 12 knots Thursday
afternoon and early evening. For OAK Airport stratus /IFR/ prevails
tonight and Thursday morning, mixing out to VFR 19z. Stratus /IFR/
returns Thursday evening and night. West wind 5 to 15 knots.
Monterey Bay Terminals...Stratus /MVFR-IFR/ prevails tonight and
Thursday morning. Conditions improving to MVFR-VFR late Thursday
morning and afternoon. Stratus /IFR/ redevelops Thursday night.
Onshore winds 5 to 15 knots.
&&
.MARINE...
(Tonight through next Tuesday)
Issued at 915 PM PDT Wed Jun 24 2026
Fresh to strong breezes and rough seas will resume across the
waters tonight through the latter part of the week. Occasional
gale-force gusts will develop along the coastal waters north of
Point Reyes. Hazardous conditions for small crafts will develop
tonight and continue through at least early Friday. Long period
southwest swell will persist through the extended forecast.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM Thursday to 9 AM PDT Friday for
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 3 PM Thursday to 3 AM PDT Friday for
Mry Bay.
Small Craft Advisory from 9 AM Thursday to 9 AM PDT Friday for
Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 9 PM Thursday to 9 AM PDT Friday for
Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PDT Friday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Zuber
LONG TERM....Zuber
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Wed Jun 24 22:30:03 PDT 2026
From the National Weather Service
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