Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KMTR 031827
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1127 AM PDT Mon Oct 3 2022

.SYNOPSIS...A gradual warming trend and dry conditions are
expected through the upcoming week as high pressure builds over
the region.

&&

.DISCUSSION...as of 03:51 AM PDT Monday...Marine stratus remains
offshore on nighttime satellite imagery. The stratus deck is about
40 miles west of San Francisco, 20 miles west of Pt Reyes, and 50
to 60 miles west of the Monterey Peninsula/Big Sur coast. Removed
mention of patchy fog in the forecast for this morning since we
still have mainly clear skies over the region and the marine layer
continues to be deep enough that it is fairly mixed and isn`t
well defined. The only exception is a small patch of low clouds
that developed over the Monterey Airport with bases around 400 to
500 feet and another small patch in far northwest Sonoma County
east of Sea Ranch. In the absence of any stratus, temperatures are
running 2 to 8 degrees cooler than 24 hours ago since more of
yesterday`s daytime heat has been able to radiate away.

A high pressure ridge is rebuilding along the west coast and it
will persist for much of this week. The onshore gradient is
showing signs of weakening so we are on track to start the warming
trend today. Highs today will be a touch warmer inland with
similar conditions on the coast to yesterday. Highs inland should
warm into the mid 70s to mid 80s with some upper 80s across
southern Monterey county. The ridge will slowly strengthen and
expand by midweek which will keep us in a gradual warming and
drier trend through the work week. The thermometer should top out
between Wednesday into Friday when inland highs will reach the mid
80s to mid 90s. Meanwhile the coast will be in the 70s with upper
70s to low 80s around the Bay shoreline. As we get into the
warmer part of the week, HeatRisk remains low for much of our CWA
with some spots of moderate risk in portions of the interior.
Moderate HeatRisk is a reminder to those that are more sensitive
to heat (elderly, sick, very young) to make sure they stay cool
and hydrated.

Over the weekend, it looks like the ridge weakens and our region
will experience slight cooling. Saturday will still see some low 90s
in the far interior, but by Sunday, it looks like we inland areas
will stay in the 80s.

&&

.AVIATION...As of 11:25 AM Monday...For the 18Z TAFs. Widespread
VFR and NW winds today. SFO-SAC (onshore) gradient is expected to
ramp up this afternoon. Model guidance indicates the gradient will
reach around +3.5 mb around 00z today, and as a result will see
stronger W/NW winds compared to yesterday across the region. The
onshore push will also bring the stratus deck (that is currently
~50 miles off the coastline) inland. MVFR/IFR cigs likely for
coastal terminals tonight with highest confidence of KOAK and KMRY
getting cigs after 06z today. Moderate confidence of KSFO and
KSJC seeing cigs and lesser so for KLVK. North Bay terminals more
likely to see reduced visbys from valley fog formation overnight.
Clearing times will be between 17-18z Tuesday morning.

Vicinity of SFO... VFR through the day. Breezy W/NW winds today
around 15 kts with gusts up to 22 kts at KSFO. Stratus will flow
in via the Golden Gate around 06z, first reaching KOAK then KSFO
later in the night/early morning (~10z). Cigs expected to be
around 1000 feet, so borderline MVFR/IFR conditions. Clearing
around 17-18z tomorrow morning where VFR will resume.

KSFO Bridge Approach... Similar to SFO.

Monterey Bay... VFR and onshore winds today. Stratus will return
to KMRY after 06z tonight. Less confidence on timing for stratus
return at KSNS, but onset will be delayed compared to KMRY. IFR
cigs tonight becoming LIFR with reduced visbys in the early
morning hours expected. Clearing around 18z Tuesday morning.

&&

.MARINE...as of 08:32 AM PDT Monday...Northwest winds will
increase today into tonight across the waters. Gusty winds
expected this afternoon near coastal jets and gaps, such as
through the Golden Gate. Winds will remain breezy through midweek,
making for hazardous seas especially for smaller craft. A new
northwest swell at 17 to 19 seconds arrives mid week as winds
diminish toward the end of the week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...Mry Bay from 3 PM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 PM
             SCA...Pt Arena to Pt Reyes 0-10 nm from 3 PM
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm

&&

$$

PUBLIC FORECAST: Bingaman
AVIATION: McCorkle
MARINE: McCorkle

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.