FXUS66 KMTR 152101
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
201 PM PDT Wed Apr 15 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 157 PM PDT Wed Apr 15 2026
- Seasonably warm temperatures Friday into the weekend
- Periods of gusty offshore winds, especially at higher
elevations, Wednesday afternoon through early Friday morning
- Seasonably cool temperatures and beneficial rain Sunday into
early next week
&&
.SHORT TERM...
Issued at 157 PM PDT Wed Apr 15 2026
(This evening through Thursday)
Breezy onshore winds are expected along the coast and across the
higher elevations through this evening as a deep upper level low
pushes into the Pacific Northwest. A dry cold front will push
through the region late this evening into Thursday morning. Not
anticipating fog to develop tonight but patches of low level stratus
are likely as the cold front moves through the region. Early morning
cloud cover today is helping to keep our high temperatures cooler
with 60s expected across the interior and 50s to 60s expected along
the coast. Cooler overnight temperatures are expected Thursday
morning across the North Bay where clear skies will allow for enough
radiational cooling for lows to drop into the upper 30s. The rest of
the Bay Area and coastal Central Coast will have patchy stratus
insulation overnight which will keep lows in the 40s. Elevated
terrain in the eastern Santa Clara Hills and Gabilan Range will be
slightly cooler with lows in the upper 30s.
Heading into Thursday we see the return of gusty offshore winds. A
deep upper level trough will shift into the Northern Rockies and
progress eastwards. While not a classic inside slider, the trough is
enough to generate moderate to strong northerly offshore winds
across the region. These winds will be strongest across the interior
North Bay Mountains, the Diablo Range, and favored mountain
gaps/passes. Peak gusts will be between 35 to 45 mph with locally
higher gusts possible across the highest ridgelines of the Mayacamas
Mountains (bordering Lake, Yolo, and Solano Counties). Fire weather
concerns remain minimal due to the recent wetting rains but any
residents or anyone visiting the mountains Thursday/Friday should be
prepared for gusty winds.
&&
.LONG TERM...
Issued at 157 PM PDT Wed Apr 15 2026
(Thursday night through next Tuesday)
Gusty offshore winds will continue into early Friday morning before
winds dissipate Friday afternoon/evening. The deep upper level
trough will continue to progress eastward while a progressive high-
amplitude ridge moves into the West Coast. As the ridge moves in
winds will ease and warmer temperatures will return Friday and
Saturday. Interior highs will reach the low to mid 70s while coastal
highs stay in the 50s to 60s. The interior Central Coast remains the
warmest with highs peaking in the upper 70s to low 80s with
temperatures peaking on Saturday. Morning temperatures will be
chilly on Friday with portions of the interior Central Coast
dropping into the low to mid 30s (vicinity of Bradley and
Parkfield).
Unsettled weather returns late Sunday into early next
week as a deep upper level trough pushes into the West Coast. This
trough will move down from the Gulf of Alaska and is associated with
a surface low pressure system moving into Northern California. Cold
frontal passage is expected to occur Sunday into Monday with
widespread rain across the region. Rainfall is expected to be
beneficial with 1-2" across the coastal mountains and half an
inch to an inch across the lower elevations. There is a slight
(10-15%) chance of thunderstorms Sunday and Monday afternoons.
Temperatures look to be seasonable to seasonably cool in the 50s
to 60s Monday/Tuesday. Cluster guidance is in good agreement that
a trough will develop but there is still some uncertainty as to
when the trough will arrive/how fast it will progress eastwards.
It is possible that this system will continue to slow down and the
rain window will shift more Monday-Wednesday than Sunday-Tuesday
(as it is in the current forecast). No real wind concerns with
this upcoming system. Conditions will get breezier Sunday into
Monday across the higher terrain, along the coast, and across
mountain gaps/passes but it will stay below wind advisory
criteria.
&&
.AVIATION...
(18Z TAFS)
Issued at 1059 AM PDT Wed Apr 15 2026
AM clouds/fog have given way to mostly VFR for 18Z tafs. Some
coastal strato-cu will occasionally impacts HAF and MRY. A weak
boundary will sweep through this evening/early tonight bring a
return of brief MVFR CIGS from approx 03Z-08Z depending on
terminal. Behind the boundary offshore flow and drier air rush in
kicking LL moisture out with VFR returning. Moderate wind speeds
are expected at all TAF sites mentioned above throughout the day
and night with some experiencing strong gusts. Winds are expected
to decrease slightly by tomorrow morning before increasing again.
Vicinity of SFO...VFR with a few CU hugging the hills to the
west. Probabilistic guidance brings frontal CIGS to the San Bruno
gap close to 03Z and then over the terminal by 05-06Z. Once the
boundary goes through drier air erodes MVFR cigs by 09-10Z
SFO Bridge Approach...CIGS arrival and clear tonight will be 30-60
min after terminal.
Monterey Bay Terminals... Around 03-04z tonight, lower CIGs will
make their way through MRY, and SNS resulting in MVFR conditions.
These low clouds will eventually dissipate out by early to mid-
morning tomorrow and conditions will shift back to VFR, except at
MRY where they will stick around through the end of the TAF
period.
&&
.MARINE...
(Today through Monday)
Issued at 353 AM PDT Wed Apr 15 2026
Fresh northwest breezes and moderate seas will continue over the
coastal waters through today. A mostly dry cold front will push
through tonight followed by gusty northwesterly winds Thursday.
These winds will build rough seas of 10-12 feet across the exposed
coastal waters. Winds will ease back to moderate northwest breezes
Friday through Saturday, allowing seas to gradually subside.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Thursday for Mry Bay.
Small Craft Advisory from 9 PM this evening to 9 PM PDT Thursday
for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10
nm.
Small Craft Advisory until 9 PM PDT Thursday for Pt Reyes to
Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 AM PDT Friday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Small Craft Advisory from 9 PM this evening to 3 AM PDT Friday
for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 3 AM Thursday to 3 AM PDT Friday for
Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...MM
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Wed Apr 15 14:30:02 PDT 2026
From the National Weather Service
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