FXUS66 KSGX 231628
Area Forecast Discussion
National Weather Service San Diego CA
928 AM PDT Thu Mar 23 2023
Widely scattered light showers will continue today from the coast
to the mountains and are expected to end tonight. Stronger and
gusty west to northwest winds are expected for the mountains and
deserts for tonight into Friday morning with the stronger gusts
mostly 50 mph or less. For Saturday through Monday, dry weather
is expected with warming on Monday. Lower level flow will
fluctuate between weakly onshore and weakly offshore. A low
pressure system from the northwest may bring precipitation during
the middle of next week.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
930 AM Update...Radar imagery from KNKX and KSOX shows quite a bit
of scattered shower activity developing and moving inland. With a
passing weak 500mb wave to the north, this activity will likely
continue through the afternoon. PoPs and Wx grids have been
updated to reflect this potential also highlighted in hi-res
guidance. Otherwise, the forecast beyond this afternoon looks to
be on track.
.SHORT TERM (Today through Saturday)...
The low pressure system that brought precipitation on Tuesday and
Wednesday will continue to weaken and move inland today. Widely
scattered light showers will continue today from the coast
to the mountains with additional rainfall of mostly less than
one-tenth inch near the coast to one-tenth to one-third inch in
the mountains with the greater coverage and amounts in San Diego
County. A snow level near 4500 feet will rise to 5000 feet in the
The San Diego River at Fashion Valley is falling faster than
forecast and fell below monitor stage on Wednesday afternoon.
Meanwhile, the Santa Margarita River is falling slower than
forecast and is still about one-half foot above monitor stage.
High temperatures for most areas will be slightly warmer than
Wednesday with Friday a few to around 5 degrees warmer than
today. Then slightly cooler for the deserts on Saturday and
slightly warmer for the coast and valleys. High temperatures for
inland areas will be mostly 10 to 15 degrees below average.
A weak low pressure system moving inland to the north in fast
northwest flow aloft will strengthen the onshore flow in southern
California and bring a round of stronger and gusty west to
northwest winds for tonight into Friday morning with the stronger
gusts on the desert slopes of the mountains mostly 50 mph or less.
.LONG TERM (Sunday through Wednesday)...
Weak onshore flow on Sunday will become weakly offshore on Monday.
High temperatures on Sunday may be a degree or two warmer than
Saturday with Monday another few to around 5 degrees warmer than
Sunday. However, even with the warming high temperatures on Monday
for inland areas will still be 5 to 10 degrees below average.
For Tuesday night and Wednesday, a low pressure system from the
northwest may bring a return of precipitation. While there are
differences in the model guidance, it is not expected to have
access to moisture from an atmospheric river and precipitation
amounts are unlikely to be as much as from some recent storms.
231545Z...Coast/Valleys/Mountains...BKN-OVC020-040 with -SHRA this
morning gradually decreasing this afternoon and evening. CIGS
locally below 2000 feet with vis 3-5SM in heavier SHRA. Mountains
occasionally obscured in FG and -RA. Intermittent SCT030 near the
coast this afternoon.
Deserts...SCT clouds 8000-10000 feet MSL today and tonight.
Small Craft Advisory in effect through 11 PM Friday for strong
northwest winds and choppy, hazardous seas. Another round of
stronger winds is expected late Saturday, with weaker northwest
winds Sunday and Monday.
High Surf Advisory Surf through 9 PM for San Diego County for surf
of 6 to 12 feet. Above average surf in Orange County with sets from
3 to 7 feet. Hazardous swimming conditions at all beaches today.
Swell and surf will subside during the day.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
CA...High Surf Advisory until 9 PM PDT this evening for San Diego
County Coastal Areas.
PZ...Small Craft Advisory from 2 PM this afternoon to 8 AM PDT Friday
for Coastal Waters from San Mateo Point to the Mexican
Border and out to 30 nm.
Small Craft Advisory until 11 PM PDT Friday for Waters from San
Mateo Point to the Mexican Border Extending 30 to 60 nm out
including San Clemente Island.
NWS SGX Office Area Forecast Discussion