Small Craft Advisory 1, NWS San Diego, CA

Area Forecast Discussion
National Weather Service San Diego CA
914 PM PST Thu Jan 20 2022

.SYNOPSIS...
Strong and significant Santa Ana winds are expected across the
area late Friday through Saturday, with winds peaking in strength
Saturday morning. Winds will relax late Saturday into Sunday. A
dry airmass will spread across southern California this weekend
and last through mid next week, with warm days and cool nights
expected.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

.EVENING UPDATE...
After a breezy day across the mountains and foothills, light
offshore flow now prevails across the region. These light north
and east winds will occur through the night for places along and
west of the mountains. Strong Santa Ana winds are still expected
as an area of low pressures dives south across the desert
southwest over the next couple of days. Winds will ramp up
starting Friday afternoon and peak in intensity Friday night into
Saturday morning. The positioning of this low pressure center is
in bit more of alignment in the latest model guidance, focusing
on the center of the low going over the Colorado River Valley
vicinity. Pressure and moisture cross sections and local WRF/HRRR
models do indicate a slight chance for some light precipitation
possible for the mountains and deserts on the backside of the low
for the weekend. We will continue with the current forecast this
evening and refine the forecast in the coming days as the event
draws closer.

.PREVIOUS DISCUSSION (As of 150 PM Thursday)...

&&

A strong upper level low will reach the northern Rockies on
Friday, then drop south into southwest Arizona or southeast
California on Friday as a closed upper low. A surface high
pressure will develop over the Great Basin behind the upper low on
Friday, peaking at 1042 mb. While there has been some variability
in the position of this upper low, ensembles members have
generally been in good agreement in the last couple of days. The
strong upper level support with this system will result in strong
and significant Santa Ana winds for SoCal late Friday through
Saturday.

Northeast winds will begin to develop over the northern mountains
and Inland Empire late Friday afternoon, then spread south into
San Diego County Friday night. Winds will be strongest on the
coastal mountain slopes of the San Bernardino mountains, where
gusts in excess of 70 mph are expected. For the Inland Empire and
inland Orange County, expect widespread gusts of 40 to 60 mph. The
northern mountains, Inland Empire and inland Orange County have
all been placed under a High Wind Warning, beginning late Friday
afternoon and continuing through Saturday afternoon.

Winds don't look to be as strong in the San Diego County mountains
and valleys, though gusts to 55 mph are possible. A Wind Advisory
is in effect for those areas from late Friday night through
Saturday afternoon. Additionally, gusty winds are expected along
the Orange County coast, with gusts to 45 mph expected, so a Wind
Advisory will be in effect there as well.

Humidity values will drop into the low 20s to upper teens in the
Inland Empire and inland Orange County Saturday afternoon.
Combined with the windy conditions, there may be a few hours of
elevated to near-critical fire weather conditions Saturday
afternoon.

Winds will diminish late Saturday into Sunday as the surface high
pressure relaxes, though lighter northeast winds will continue on
Sunday, mainly through the passes and windiest canyons. The upper
level low will push inland late Sunday. For early next week, there
remains quite a bit of uncertainty in the pattern, with another
upper level low potentially developing near the West Coast or over
the Great Basin.

&&

.AVIATION...
210430Z...Mostly clear skies with unrestricted VIS through Friday
morning. SCT-BKN low clouds with bases 1000-1500 ft MSL could return
to the San Diego County coastal and valley areas Friday
afternoon but will dissipate by late afternoon/evening.

Strong and gusty northeast to east winds will develop again after
22Z in the mountains, foothills and the inland valleys. These
winds will strengthen Friday evening/night, extending to the
coastal areas of Orange and San Diego Counties by early Saturday
morning. Mdt to strong up/downdrafts and LLWS could impact KONT,
KSBD and KSNA. KCRQ and KSAN could also be impacted Friday night
early Saturday morning but chances are lower.

&&

.MARINE...
Strong and gusty northeast winds will develop Friday evening and
continue into Saturday. Strongest gusts of 25-30 knots are expected
in a wide corridor between Camp Pendleton and San Clemente Island,
which would produce hazardous boating conditions. Otherwise, no
marine weather hazards are expected through Monday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from midnight Friday night to 6 PM PST Saturday
     for San Diego County Mountains-San Diego County Valleys.

     High Wind Warning from 3 PM Friday to 6 PM PST Saturday for
     Orange County Inland Areas-Riverside County Mountains-San
     Bernardino County Mountains-San Bernardino and Riverside
     County Valleys-The Inland Empire-San Gorgonio Pass Near
     Banning-Santa Ana Mountains and Foothills.

     Wind Advisory from 3 PM Friday to 6 PM PST Saturday for Orange
     County Coastal Areas.

PZ...NONE.
&&

UPDATE/PUBLIC...APR/Connolly
AVIATION/MARINE...PG