Graton, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

203
FXUS66 KMTR 202130
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
Issued by National Weather Service Eureka CA
230 PM PDT Sun Apr 20 2025

...New AVIATION...

.SYNOPSIS...
Issued at 1251 AM PDT Sun Apr 20 2025

A slight warming trend will continue through Monday before
cool and cloudy weather returns mid to late week.

&&

.UPDATE...
Issued at 927 AM PDT Sun Apr 20 2025

Clear conditions expected to persist this afternoon. Highs are
forecast to reach the low to mid 70s across the interior and upper
50s to mid 60s along the coast. No changes to the forecast at
this time.

&&

.SHORT TERM...
(Today and tonight and Monday )
Issued at 228 PM PDT Sun Apr 20 2025

The stratus blanketing the Bay Area and Central Coast has receded
much faster today than it has over the past few days. For
example, stratus did recede from Santa Rosa until after 3PM
yesterday but cleared completely by 1PM today. The 24 hour
temperature change shows temperatures are running on average 5 to
10 degrees warmer today than they were at this time yesterday as a
result of the much more rapid clearing of stratus today. A few
sites across areas of elevated terrain are even running up to 15
degrees warmer today than they were yesterday! That being said, we
did nudge high temperatures across the North Bay Valleys down by
a few degrees (changing the forecast high from the low 70s to the
upper 60s) in order to account for stratus lingering longer across
the NB Valleys than it did across the rest of the region. In
general, temperatures will be fairly seasonal today with highs in
the upper 60s to mid 70s across the interior. Cooler coastal
temperatures prevail with highs in the upper 50s to low 60s.
Temperatures are expected to rise further on Monday as zonal flow
develops with high temperatures in the mid 70s to low 80s across
the interior and low to mid 60s along the coast. Building high
pressure and zonal upper level flow will help to compress the
marine layer to around 500 to 1000 ft overnight tonight. This
should serve to limit inland stratus intrusion overnight and keep
stratus confined more closely to the shoreline/coastal areas.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 228 PM PDT Sun Apr 20 2025

Zonal flow persists through Tuesday with temperatures remaining
seasonal to slightly above normal in the mid to upper 70s for
interior locations and low to mid 60s along the coast. Heading
into Wednesday, a weak shortwave trough will move in and kick
start a  cooling trend across the region. This will allow
temperatures to cool into the upper 60s to low 70s across the
interior and mid 50s to low 60s along the coast. This system is
not expected to produce any precipitation with it but may result
in some locally breezy winds. Current NBM and local high
resolution WRF guidance keep the highest gusts out over the marine
environment but gusts between 20 to 30 mph are possible across
the higher terrain. The cooling trend continues Thursday into the
weekend with high temperatures dropping into the low to mid 60s
across the interior and mid 50s to low 60s along the coast.
Heading into Friday, a deeper upper level trough will move into
the West Coast and bring a low chance for light rain to
northernmost portions of the Sonoma and Napa Counties. At most,
this system looks to bring a few hundredths to a tenth of an inch
to northern Sonoma and Napa Counties with some coastal drizzle
possible further south. Confidence remains low overall that the
North Bay will experience any rainfall from this system due to
guidance continuing to trending rain chances lower and lower
across our CWA and shifting the rain further north. This system
does look as though it will produce breezier conditions across the
region with guidance showing widespread gusts to around 25 to 30
mph and locally stronger gusts across the elevated terrain.

&&

.AVIATION...
(18Z TAFS)
Issued at 1158 AM PDT Sun Apr 20 2025

Stratus continues to clear this morning, with coastal communities and
the North Bay Valleys taking the longest to dissipate. Expect VFR
conditions at most sites within a few hours and then persisting into
the early evening. Guidance shows another intrusion of the marine
layer tonight, which will likely impact the coastal KSFO, KOAK,
KHAF, KMRY, and KSNS with MVFR to IFR cigs possible. North Bay sites
show a mix of stratus and mixed visibilities, though confidence is a
touch lower on how low the vis could fall. Trended towards IFR cig
and vis for these sites. Expect another round of clearing by mid to
late tomorrow morning with any development.

Vicinity of SFO... Stratus has more or less cleared this morning,
with only a few clouds hanging around. Expect VFR conditions to
prevail through the evening, with uptick breezy west to west-
northwesterly winds of 10-15kt possible. Winds should fall below
10kt before 06Z, with MVFR cigs returning during the early overnight
hours. Leaned towards the persistence forecast, which should have
MVFR cigs eroding just before or around 18Z.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Clear skies around much of the Monterey Bay
region this morning, with VFR conditions likely prevailing through
the early evening. Then MVFR to IFR cigs are expected overnight with
skies clearing by mid to late morning tomorrow.

&&

.MARINE...
(Today through Friday)
Issued at 927 AM PDT Sun Apr 20 2025

Breezy to gusty north/northwest winds are building in the northern
waters along with building north swell. Winds look to increase and
spread across the outer waters into the work week. The occionally
near gale gusty northerly winds look to become more widespread
into the mid week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm until 3 AM
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm

&&

$$

PUBLIC FORECAST: Default
AVIATION/MARINE: Default

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