FXUS66 KMTR 131205
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
505 AM PDT Mon Apr 13 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1136 PM PDT Sun Apr 12 2026
- Slightly cooler to near normal temperatures through Thursday
- Periods of gusty winds, especially at higher elevations
Wednesday through Friday
- Warmer temperatures return Friday into the weekend
&&
.SHORT TERM...
Issued at 1136 PM PDT Sun Apr 12 2026
(Tonight through Tuesday)
The coverage in light shower activity continues to gradually shift
south late tonight into early Monday morning. Earlier this evening
the KOAK sounding reported a 23.0C temperature at H50 which is in
the 10th percentile for this time of the year. That cold core aloft
helped support continued light shower activity after sunset from the
SF peninsula south to Monterey Bay. The upper low will become more
unorganized as it moves farther inland, evolving into a positively
tilted upper trough extending from the Great Basin southwest into
SoCal today. Lingering offshore scattered light showers will
occasionally drift into the Big Sur coastline through mid-morning
today with maybe a trace to a few hundredths of rain. Mondays highs
at lower elevations will run around 5F-10F degrees below normal,
with higher elevations 10F-20F degrees below normal. Cooler than
normal temperatures persist tonight into early Tuesday, especially
farther inland with cooler than normal air aloft persisting much of
the work week.
&&
.LONG TERM...
Issued at 1136 PM PDT Sun Apr 12 2026
(Tuesday night through next Sunday)
A progressive shortwave pattern sets in Tuesday through Thursday
behind the exiting trough defining the term 'gradual warming' with
most locations seeing an increase of 1 or 2 degrees each day through
the middle of the week. A developing trough shifts south from the
Pacific Northwest on Wednesday. There is a slight chance for
rainfall across the North Bay Wednesday afternoon as the trough axis
pivots east and south, but any rainfall will be measured in
hundredths of inches with no impacts. Gusty winds will develop on the
backside of the exiting trough later Wednesday through Thursday
and into the early morning hours of Friday. However, updated
deterministic guidance has shifted the disturbance farther east
than this time last night with less of an 'inside slider' signal.
Winds will still be gusty at times especially at higher elevations
but impacts seem low. There is also a signal for the potential of
another round of rainfall toward the end of next weekend into the
beginning of next week.
&&
.AVIATION...
(12Z TAFS)
Issued at 505 AM PDT Mon Apr 13 2026
Lingering light showers last into the late morning for the South Bay
and around the Monterey Bay. Pockets of fog look to affect portions
of the North Bay into the mid morning before clearing. Winds stay
mostly light through the late morning but these winds increase into
the afternoon becoming breezy to gusty around the SF Bay and
portions of the immediate coast. As winds increase, scattered mid-
level clouds begin to thin with mostly clear skies expected into the
afternoon. MVFR-level CIGs return to MRY into the evening as winds
begin to reduce. CIGs look to build at HAF, LVK, and SNS into early
Tuesday.
Vicinity of SFO...VFR through the TAF period. Shower activity
lingers south of the terminal through the mid morning. Scattered mid-
level clouds clear into the late morning and breezy to gusty west-
northwest winds build into the afternoon. These winds look to last
through Monday night before gusts cut off and winds turn westerly
into Tuesday morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Light showers continue to move through the
area until the late morning. Expect northwest winds to build into
the afternoon as cloud cover thins. MVFR CIGs build around the bay
and at MRY into the evening as winds reduce. Scattered cloud cover
will affect SNS into the evening, but SNS doesn't fill until early
Tuesday morning.
&&
.MARINE...
(Today through Saturday)
Issued at 505 AM PDT Mon Apr 13 2026
Showers linger into the late morning before eroding. Winds stay
light through the morning and early afternoon, increasing to a
moderate to fresh breeze through Wednesday. Winds build again on
Thursday leading to near gale force gusts into the end of the work
week. Moderate seas continue through Wednesday before rough seas
arrive on Thursday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
Wednesday 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
Tuesday for Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
evening for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory from 3 PM Tuesday to 3 AM PDT Wednesday for
Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...JM
LONG TERM....JM
AVIATION...Murdock
MARINE...Murdock
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Prepared by Boulder-Creek.com Weather at: Mon Apr 13 08:30:02 PDT 2026
From the National Weather Service
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