*Annual Rainfall is based on the California Water Year,|
which runs from October 1 through September 30.
FXUS66 KSGX 281638
Area Forecast Discussion
National Weather Service San Diego CA
838 AM PST Sun Feb 28 2021
Gusty Santa Ana winds through and below passes and along the
coastal foothills will continue through early Monday. East winds
will drop off on Monday, but it will be very dry and a little
warmer. Cooler, onshore flow returns Tuesday. There is the
potential for a storm system to move across SoCal Wednesday
night. Precipitation associated with this storm could break out
as early as Wednesday afternoon and continue into Thursday. Dry
and warmer weather will return to wrap up the week.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
Skies are clear this morning with gusty northeast winds ongoing
across the mountains, foothills, Inland Empire, and Orange County.
As of 8 AM, Marshall Peak and Fremont Canyon were the two standout
locations, reporting peak gusts of 83 and 79 mph, respectively.
Numerous other sites, mostly in the Inland Empire, reported gusts
in the 50-60 mph range. A High Wind Warning remains in effect
until 3 PM. Winds will weaken this afternoon, then turn
easterly and continue to weaken on Monday. A Wind Advisory remains
in effect from 3 PM today through 3 AM Monday to account for the
gusty east winds, and includes portions of San Diego County.
Today will be warmer near the coast, where highs will be in the
low 70s. Elsewhere, the cold air advection associated with the
trough digging across the desert SW will keep things cooler,
generally a couple degrees below normal in the valleys but 5 to 10
degrees below normal for the mountains and deserts. More
widespread warming takes on Monday and Tuesday as an upper level
ridge moves over and weaker offshore flow prevails.
Latest GEFS/EPS ensemble solutions still favor midweek
precipitation, though the CMC isn't quite on board yet. While all
ensembles and deterministic runs have trended slower bringing the
closed low across So Cal, there is still a decent spread in the
timing. Showers could begin as early as Wednesday afternoon,
though that appears to be one of the less likely scenarios. Based
on current data, the best chance of precipitation would be
Wednesday evening through Thursday morning, with a few showers
possibly lasting into Thursday afternoon. Amounts still look to be
on the lower side, around 0.10-0.25" for the coasts/valleys.
Mountains could see around 0.25-0.50" with southwest facing slopes
being favored. There is the potential for higher amounts
depending on how the low tracks/how much tropical moisture it
taps, and if any thunderstorms develop.
The storm system will move rapidly east on Thursday, setting up a
fair and warmer end to the week. There is a chance of a passing
system on Sunday that may deepen the marine layer with some cooling,
but for now any precip potential is small.
281605Z...Clear skies with unrestricted visibility through tonight.
North to northeast winds will continue over the mountains and into
many valley and some coastal locations this morning, with local
surface 20-30 kts and gusts to 55 kts. These winds will produce
moderate to strong up/downdrafts and LLWS over and west of the mtns
through this afternoon, including near KONT, KSBD and KSNA. Winds
will decrease somewhat this evening, but will remain breezy through
Monday morning, with gusts 30-40 kts over the mountains and into the
Areas of northeast winds with gusts 20 kts possible at times this
morning over the coastal waters. Otherwise, no hazardous marine
conditions are expected Monday through Friday.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
CA...Wind Advisory until 3 AM PST Monday for San Diego County
Mountains-San Diego County Valleys.
High Wind Warning until 3 PM PST this afternoon 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 this afternoon to 3 AM PST Monday for
Riverside County Mountains-San Gorgonio Pass Near Banning.
Wind Advisory until 3 PM PST this afternoon for Orange County