FXUS66 KSGX 271021
Area Forecast Discussion
National Weather Service San Diego CA
221 AM PST Sun Nov 27 2022
A building marine layer and troughing over the region will
contribute to cloudier skies, cooler weather and windy conditions
in the coming the week. Patchy fog may occur near the coast
through the morning hours today as the marine layer builds. An
open wave trough will plunge into the western part of the country
through Tuesday, bringing in gusty west winds across the
mountains and deserts as well as a slight chance of light showers
along the coastal mountain slopes by Monday night. Cool and dry
weather will continue for the middle of the week. A trough of low
pressure will impact the West Coast by the end of the week, where
chances of precipiation start to come into the picture.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
.SHORT TERM (Sunday through Tuesday)...
Light offshore flow is battling the thin marine layer early this
morning. The offshore push should keep most clouds and fog over
the water, but the immediate coast has a slight chance of seeing
patchy dense fog throughout this morning. Another nice day will
occur for our Sunday, with mostly clear skies and temperatures in
the 60s and 70s for many, with 50s expected for the higher
After today, bid adieu to the near to above normal high
temperatures we have been treated to over the past several days.
An open wave trough that is currently over the northwestern U.S.
will sink south into the Great Basin and Intermountain West over
the next couple of days, bringing cooler and windier weather for
our area. As the trough axis passes over the region by Monday
into Tuesday, gusty west winds will ramp up across the mountains
and deserts. Confidence remains high that winds will peak
for the evening hours on Monday with gusts 30-45 MPH across many
mountain and desert areas, locally over 60 MPH along favored areas
along the desert mountain slopes, especially in San Diego County.
Driving conditions will be hazardous with possible blowing dust in
the deserts and on the roadways, especially on Instates 8 & 10
through the mountains.
.LONG TERM (Wednesday through Next Weekend)...
A brief lull in the action will be expected for the middle of the
week as weak troughing over the State will keep temperatures below
average. As we contend with this, model clusters start to depict
another area of low pressure coming into the Pacific Northwest.
There is still a bit of uncertainty on the positioning and
strength of this system and what impact it will have on us here in
SoCal. Ridges of high pressure across the Southern Plains and up
in Alaska will dictate where exactly this trough sets up.
Ensemble models are starting to become in better agreement of the
trough setting up somewhere along the West Coast, which would be
able to entrain moisture across the State by the end of the week.
For our area, our confidence is steadily increasing on the
occurrence of rainfall later in the week with most areas seeing a
20-30% chance, with the onset possible by Thursday. Confidence is
still low on the onset timing and on how much rainfall and
snowfall we will see. The pattern may remain active through the
weekend with more cooler and wet weather, though details on this
remain somewhat uncertain.
271015Z...Mostly clear skies persist early this morning, although we
do have a few patches of low clouds and fog near the mid-San Diego
County coast. Through mid-morning, a few patches of low clouds and
fog could affect the immediate coast, including the SAN and CRQ
terminals, but the overall chance of ceilings at those sites remains
low, with visibility of 1 mile or less, through mid-morning. Any vis
restrictions that develop should clear by 16Z this morning. Better
chances for low clouds and fog mainly in the foothills and some
coastal mesas will return this evening.
Patchy fog and low clouds will affect the coastal waters tonight
into Sunday morning. Visibility could drop to 1 NM or less at times.
Monday evening into Tuesday, Gusty west-northwest winds up to 30 kts
and choppy seas over the outer coastal waters are to be expected,
with conditions hazardous for small craft. Strongest winds and
highest seas will be in the outer coastal waters near San Clemente
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
NWS SGX Office Area Forecast Discussion