Walnut Creek, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

629
FXUS66 KMTR 230529
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
929 PM PST Sun Feb 22 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 643 PM PST Sun Feb 22 2026

 - Dry and warmer for Monday.

 - Unsettled weather with periods of rain and wind for Monday
   night through Wednesday.

 - Warming and drying trend kicks off Thursday with the return of
   above normal temperatures.

&&

.UPDATE...
Issued at 643 PM PST Sun Feb 22 2026

Water vapor imagery shows a beautiful and complex weather pattern
over the Eastern Pacific this evening, with two storm force lows
near 49.3 North / 135.2 West and 38.1 North / 144.5 West,
respectively. Meanwhile, a transitory ridge of high pressure is
building into Northern California, ahead of another developing low
near 27.8 North / 142.3 West.

Most areas today saw warmer temperatures in response to the
building ridge and clear skies, and in fact are still trending up
4 to 8 degrees warmer at this hour than this time last night.
However, the North Bay remain under the influence of the moisture
plume, just enough to keep light warm air advection rain going
across a good portion of Sonoma County. The coastal mountains of
Sonoma County have seen the brunt of the rainfall, with 24 hour
totals ranging between 0.60 and 1.21 inches and with Venado being
the top performer with 1.21 inches. Some of this rain did spread into
Santa Rosa as well, with the airport reporting 0.09 inches.
Current radar also continues to show some light returns, with
hourly rainfall rains of just a few hundredths at this time. As
the moisture plume shift north tonight, expect these light showers
to taper off, with drier conditions developing. These drier
conditions will prevail through most of Monday, before the rain
returns tomorrow evening.

The main story for tomorrow though will be with the warmer
conditions across the region. In fact, 850 mb temperatures
increase between 3 and 6 degrees across the Bay Area and Central
Coast, and despite the increasing high cloud cover, and this
increase should translate to the surface as well. Therefore,
expect a pretty mild February day out there, with most locations
seeing day time highs in the mid 60s to lower 70s. Coastal areas
will be the coolest in the lower to mid 60s. Meanwhile, the warmest
temperatures will be in the Salinas Valley and up into South Bay.

As the moisture plume re-establishes itself across the North Bay
Monday evening, light warm advection rain will redevelop. Expect
rain and gusty winds to develop across the region, spreading from
north to south Monday night and into Tuesday. Rain will linger
across the region through Wednesday. At this point in time, it
really looks like more beneficial rain for the region. North Bay
will see the brunt of the rainfall, with between 0.5 and 1.5
inches possible, with upwards over 2.5 inches in the coastal
range. Across the Bay Area proper, expect amounts to be between
0.25 and 0.66 inches. As you come even farther south to the
Monterey Bay, a quarter inch or less is possible. Palmer

&&

.SHORT TERM...
Issued at 122 PM PST Sun Feb 22 2026
(This evening through Monday)

Not much change from the prior forecast, as the first round of rain
showers traverse cross the North Bay. Rainfall amounts so far, as of
12:30pm range from 0.0-0.17" for the valleys of Sonoma County and
between 0.15-0.55" for the mountains with the higher amounts being
found across the coastal side. Showers will linger through at least
the evening hours, before lifting north into Eureka`s service area
overnight hours. Showers may skirt by the North Bay on Monday, but
the more likely scenario is that rain holds off until late Monday
evening or into the overnight hours. That means much of the region
will be left with partly to mostly cloudy skies and temperatures in
the 60s for most of the region, perhaps the low 70s for the valleys
of the South Bay and interior Central Coast.

&&

.LONG TERM...
Issued at 122 PM PST Sun Feb 22 2026
(Monday night through next Saturday)

The bulk of the rain will arrive on Tuesday, as a surface low sets
up and taps into moisture from the southwest/tropics. This will
bring periods of rain and gusty winds on Tuesday, with chances for
rain dwindling late Tuesday night into Wednesday morning. PWATs
across the region look to be between 1.2-1.4", which combined with
orographic lift may lead to some heavier bands of rain and nuisance
flooding across the North Bay or San Francisco Peninsula and into
the Santa Cruz Mountains. Valleys may be rainshadow a bit in these
regions, with rainfall amounts decreasing as you move south and into
the Central Coast. In terms of thunderstorm chances, they look to be
null as CAPE is either extremely low or zero depending on the model,
and lapse rates are stable.

As we begin to dry out on Wednesday, upper level ridging builds in
from the south and will take hold of the forecast. A warming and
drying trend begins on Thursday and continues into the weekend.
Ensembles show ridging holding, but a low developing in the Eastern
Pacific, perhaps trying skirt over or push it eastward by the
beginning of March. PoP chances are low, but still reflect that non
zero, more like 10-20% chance of rain. The CPC outlook for this
period favors the drier scenario with leaning below normal (33-50%)
chances for rain and likely above normal (60-80%) chances for above
normal temperatures.

&&

.AVIATION...
(06Z TAFS)
Issued at 929 PM PST Sun Feb 22 2026

It`s VFR with exception of low clouds /MVFR-IFR/ and light rain
across northwestern Sonoma County. Forecast is near persistence
tonight with a drying trend returning to Sonoma County Monday then
rain redevelops over the North Bay and spreads southward Monday
night and Tuesday.

Vicinity of SFO...VFR. Light southwest wind becoming light
southeasterly to easterly tonight and Monday. Light southwest
wind redevelops Monday night with light rain developing.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Winds southeasterly 5 to 10 knots
tonight and Monday morning. Winds shifting to onshore 5 to 10
knots Monday afternoon.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 925 PM PST Sun Feb 22 2026

Southerly winds and seas diminish across the coastal waters except
across the far northwestern waters. Rain chances continue across
the northern waters then spread farther south Monday night through
Tuesday night. Winds and seas increase Tuesday then ease by
Wednesday. Dry weather prevails late this week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PST Tuesday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Canepa
MARINE...Canepa

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