FXUS66 KMTR 302126
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
226 PM PDT Thu Apr 30 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 223 PM PDT Thu Apr 30 2026
- Warming and drying trend continues tomorrow for areas away
from the coast
- Overnight and early morning stratus remains in the forecast as
the marine layer deepens into the weekend
- Cooler conditions this weekend with a chance of drizzle and/or
light rain into early next week
&&
.SHORT TERM...
Issued at 223 PM PDT Thu Apr 30 2026
(This evening through Friday)
A fetch of weak offshore flow at 925MB has resulted in clear skies
across our area this afternoon and confined stratus to the coast
along the SF Peninsula. As diurnal winds ease this evening and
decouple a relatively weak fetch of onshore flow will lead to
stratus developing through the remainder of the night into Friday
morning. Low stratus development and penetration inland to the North
Bay, Bay Area and Salinas Valley should be similar to how last night
and this morning unfolded, along with fog in the North Bay Valleys,
with clearing by mid-morning. Friday afternoons high temperatures
will be a degree or two warmer across interior locations of the
North Bay and Bay Area, even warmer over the interior Central Coast
as progressive upper level ridging shifts across the southern half
of California over the course of the day.
&&
.LONG TERM...
Issued at 223 PM PDT Thu Apr 30 2026
(Friday night through next Wednesday)
The marine layer will begin to gradually deepen by Friday night into
the weekend as an area of low pressure offshore moves south along
the coast from the Pacific Northwest to the Central Coast by Sunday.
Chances of light rain and drizzle begin to increase along the coast
Saturday night through Sunday morning. Any precipitation will be
light and mostly confined to the coastal areas and coastal ranges
with any measurable precip remaining under 0.10" of an inch, with
most spots seeing a trace to a 0.03" at most. By late Sunday, the
weak disturbance gets picked up by the southern jet and begins to
move inland across the southern half of California. There is a
slight chance of rain across the interior as it moves inland, but
once again only a trace to a few hundredths, most likely for the
higher elevations of the interior Central Coast. The clouds and
cooler temperatures aloft will translate to a notable cool down
Monday. Amplified ridging quickly moves in Tuesday, with a steady
warming trend Tuesday through the remainder of the extended
forecast.
&&
.AVIATION...
(18Z TAFS)
Issued at 1117 AM PDT Thu Apr 30 2026
Coastal locations are holding on to MVFR CIGs with VFR returning
to the remainder of the region. Onshore winds will increase this
afternoon and persist through about sunset before diminishing
slightly. The marine layer is forecast to deepen overnight to
around 1,500 ft allowing for a deeper inland penetration of
stratus. Thus, IFR/MVFR conditions are most likely late this
evening and into Friday morning. The greatest potential for LIFR
conditions are in the North Bay, San Francisco Peninsula, and
around the Monterey Bay Terminals late tonight and into Friday
morning. Fairly high confidence in sub-MVFR with medium confidence
in LIFR overnight. Onshore winds increase once again Friday
afternoon with inland conditions returning to VFR between 17Z-20Z.
Vicinity of SFO...Westerly winds dominate this TAF period with
breezy conditions expected Thursday afternoon into the evening.
The winds should decrease over night and sky cover will begin to
transition from VFR into MVFR around 03Z Friday. Moderate
confidence that MVFR CIGs will persist around 09Z Friday and
remain before mixing out by late morning Friday with the help of
increased winds and daytime heating. There may be a few lower
cloud decks in the mix around 14Z, but confidence is too low to
claim as a prevailing condition.
SFO Bridge Approach...VFR conditions will prevail until the
evening when MVFR CIGs begin to impact the Bay. Winds will have a
NW to W component through the TAF period with the wind speed trend
to match that of SFO's. MVFR CIGs are expected around 04Z though
will be slightly higher at times than those found directly over
SFO. The stratus deck should clear by late Friday morning.
Monterey Bay Terminals...MVFR at KMRY, while KSNS has returned to
VFR. There is medium to high confidence for several hours of VFR
conditions at both terminals before MVFR CIGs return early
evening. CIGs lower to IFR (40%-80%) and potentially as low as
LIFR (20%-40%) late tonight or early Friday morning and persist
through much of the morning. CIGs are then forecast to gradually
lift and scatter out between 16Z-18Z Friday.
&&
.MARINE...
(Today through Tuesday)
Issued at 1117 AM PDT Thu Apr 30 2026
A fresh to strong northwest breeze continues over the coastal
waters into this weekend. Winds will be strongest over the
northern outer waters where winds will result in moderate seas
building to between 10 to 12 feet. Winds decrease and seas subside
by late Saturday with conditions improving through the weekend.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from Saturday morning through Sunday
evening for Caz506-505-509-529-530.
PZ...Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 3 PM to 9 PM PDT Friday for Pt Arena
to Pt Reyes 0-10 nm.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PDT Saturday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...JM
LONG TERM....JM
AVIATION...RGass
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Thu Apr 30 14:30:03 PDT 2026
From the National Weather Service
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