| |
|
NWS Technical
Weather Discussion |
|
|
FXUS66 KMTR 220701
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1201 AM PDT Sat Aug 22 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1200 AM PDT Sat Aug 22 2026
- Temperatures near to slightly below seasonal averages continue
through the next week
- Warm and dry conditions persist above 1000 feet
&&
.SHORT TERM...
Issued at 1200 AM PDT Sat Aug 22 2026
(Today and tonight)
The skies are generally clear for now with patches of stratus in
favored locations and some high level clouds continuing to stream
across the interior. Offshore, a blob of cooler air lurks offshore,
evidenced by a robust stratus deck set up off the North Bay and the
San Mateo Peninsula. Through the rest of the night, this stratus
deck is expected to expand to the coastal areas and build inland
through the post-sunrise hours when the stratus will begin to
gradually clear out.
The region remains under the influence of the balance between a
cutoff low located around 200 miles west of Cape Blanco along the
southern coast of Oregon, and an upper level ridge with an axis
extending along the crest of the Rocky Mountains. Altogether this
pattern will result in temperatures which are near to slightly below
the seasonal averages, with highs today ranging from the upper 70s
to the lower 90s in the inland valleys, the middle 90s into the
triple digits for the warmest interior spots, especially the
southern tier of Monterey County, across the 70s for areas near the
Bays, and the 60s for areas along the Pacific coast. The marine
layer remains relatively stable at around 1000-1500 feet, with warm
and dry conditions persisting above the marine layer inversion as
relative humidity values reach the 10-30% range. Winds remain
relatively light and develop in an onshore flow pattern, with wind
gusts reaching 20 to 30 miles per hour along the coast, through
favored gaps and passes, and within the northern Salinas Valley.
&&
.LONG TERM...
Issued at 1200 AM PDT Sat Aug 22 2026
(Sunday through Friday)
More of the same pattern is anticipated for the rest of the week's
forecast, with a generally southwesterly upper level flow over the
region as the series of eastern Pacific troughs continues to balance
the ridge over the Desert Southwest. High temperatures are expected
to hover around the upper 70s to the lower 90s for the inland
valleys and the middle 60s to upper 70s near the Bays, with a subtle
drop in the temperatures in the early part of next week before the
ridge tries to build back towards the west. As noted by the previous
forecaster, a couple of broad low pressure areas to the south of
Baja California could develop into tropical systems sometime within
the 7-day outlook, and how those systems interact with the ridge is
highly uncertain at this time.
&&
.AVIATION...
(06Z TAFS)
Issued at 938 PM PDT Fri Aug 21 2026
VFR prevails except for patchy coastal stratus and fog /IFR/
along San Mateo County and Monterey County. Mid and high clouds,
including wildfire smoke over the north Central Coast, are moving
northeastward over the forecast area. An area of cooler near
surface air will arrive from the northwest tonight and Saturday
morning resulting in a return of stratus, fog /IFR-LIFR/ and
possibly a few patches of drizzle.
Vicinity of SFO...It's VFR except cooler surface air will arrive
overnight, this will support redevelopment of stratus /IFR/. VFR
returns 18z Saturday. West wind 10 to 15 knots tonight and Saturday
morning. West wind increasing to 20 to 28 knots Saturday afternoon
to mid Saturday evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Erosion of stratus is still taking place
to the northwest across the Monterey Bay however orographic upslope
cooling of air parcels upon arrival vicinity KMRY is occurring
supporting a scattered to broken stratus /MVFR-IFR/ ceiling. Stratus
/IFR/ is forecast to reach KSNS tonight and Saturday morning.
Wildfire smoke so far is aloft. A few patches of drizzle are
possible tonight and Saturday morning. Conditions improve to MVFR-
VFR late Saturday morning and afternoon. Stratus /IFR/ returns
Saturday evening. West to northwest winds 5 to 15 knots.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 932 PM PDT Fri Aug 21 2026
Widespread moderate to fresh northwest breezes prevail through the
weekend with slight to moderate seas. Locally strong breezes with
occasional near gale force gusts are expected in the coastal jet
regions of Point Sur and Point Reyes. Hazardous conditions for
small crafts are expected this afternoon for the bay waters and
immediate coastal waters.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt
Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt
Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 2 PM this afternoon to 3 AM PDT Sunday
for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-
60 NM-Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Canepa
MARINE...Canepa
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
Prepared by Boulder-Creek.com Weather at: Sat Aug 22 00:30:03 PDT 2026
|
|
From the National Weather
Service |
|
|
|
Copyright © 2002 All rights
reserved Boulder-Creek.com. |
|
Revised:
29 Mar 2008 09:53 -0800 GMT
(Pacific) |
|