6800ft. 
677
FXUS66 KSGX 240749
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
1249 AM PDT Wed Jun 24 2026
.SYNOPSIS...
A slight chance of showers and thunderstorms will continue into
this morning, mainly for the mountains and deserts of San
Bernardino County. A low pressure system to the north will bring
stronger onshore flow and a cooling trend for Thursday through
the weekend with Sunday high temperatures near the coolest for the
date for a few locations. Southwest to west winds for the
mountains and deserts during the afternoon and evening will
strengthen for Thursday through Saturday, then weaken for early
next week. The marine layer will deepen late in the week into the
weekend with night and morning coastal low clouds extending well
inland and onto the coastal slopes of the mountains for early
Saturday. Then warmer for early next week, but with high
temperatures remaining below average.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Friday)...
A slight chance of showers and thunderstorms will continue into
this morning, mainly for the mountains and deserts of San
Bernardino County, before southwest flow aloft brings drying for
this afternoon. A low pressure system moving southward just off
the coast of British Columbia will strengthen the onshore flow
across southern California for Thursday through the weekend with a
cooling trend.
High temperatures for today will be within a few degrees of
average for most areas and around 5 degrees above average for the
deserts. High temperatures for today will range from the lower to
mid 70s near the coast to the mid 80s to mid 90s for the Inland
Empire with 108 to 112 for the lower deserts. With the cooling on
Thursday and Friday, high temperatures on Friday will will be as
much as 5 to 10 degrees below average for the Inland Empire. High
temperatures on Friday will range from around 70 near the coast to
the 80s for the Inland Empire with 102 to 108 for the lower
deserts.
The marine layer will be around 2000 feet deep with night and
morning coastal low clouds spreading into portions of the western
valleys late each night. As onshore flow strengthens, southwest
to west winds for the mountains and deserts during the afternoon
and evening will strengthen on Thursday and Friday with gusts to
30 to 40 mph and with gusts to 65 mph in the northern Coachella
Valley below the San Gorgonio Pass.
&&
.LONG TERM (Saturday through Tuesday)...
High temperatures will cool another 5 degrees for inland areas on
Saturday and a few more degrees for most areas on Sunday. Sunday
high temperatures will be as much as 12 to 18 degrees below
average for the mountains and Inland Empire with high
temperatures ranging from around 70 near the coast to the mid 70s
to lower 80s for the Inland Empire with the mid to upper 90s for
the lower deserts. High temperatures for a few locations on Sunday
could be near the coolest for the date.
High temperatures will begin to warm next week with Monday a few
to around 5 degrees warmer than Sunday. Slower warming of a few
degrees per day will continue for Tuesday and Wednesday. High
temperatures on Tuesday will still be as much as 8 to 12 degrees
below average for the mountains and inland valleys with high
temperatures ranging from around 70 near the coast to the upper
70s to mid 80s for the Inland Empire with the upper 90s to 102
for the lower deserts.
The marine layer will deepen to around 4000 feet by early Sunday
with night and morning coastal low clouds extending well inland
and onto the coastal slopes of the mountains. The marine layer
will begin to decrease in depth early next week with coastal low
clouds for early Tuesday extending inland into portions of the
inland valleys.
Onshore flow will be strongest on Saturday with southwest to west
winds for the mountains and deserts during the afternoon and
evening gusting to 35 to 45 mph with gusts to 75 mph in the
northern Coachella Valley below the San Gorgonio Pass. The ECMWF
Extreme Forecast Index has these winds in the 80th to 90th
percentile for this time of the year, locally to the 95th
percentile. The winds will begin to weaken on Sunday with greater
weakening early next week.
&&
.AVIATION...
240530Z...Coast/Valleys...Patchy mid/high level clouds with bases
15000-20000ft MLS currently moving over the area. This cloud cover
will result in patchy low cloud formation with bases expected
between 1000-2000ft MSL. There are some patchy low clouds developing
off coastal areas and are expected to move in along the coast after
07-09Z for SD and a 30-40% chance of formation after 09-11Z for OC.
Low clouds clear land areas 16-17Z. Low clouds with similar bases
are expected to return after 03-04Z Thursday with better coverage.
Mountains/Deserts...VFR conditions expected through the TAF period
with SCT-BKN high clouds AOA 15000ft MSL. Mid to upper level clouds
will mostly clear the area by 22-23Z giving way to predominately
clear skies.
&&
.MARINE...
No hazardous marine conditions are expected through Monday.
&&
.BEACHES...
Surf will continue to increase this evening with the arrival of a 3
foot 15 to 18 second period south swell from 190 to 210 degrees.
Surf of 4 to 6 ft is expected through Thursday. Expect locally
hazardous swimming conditions and strong rip currents through the
week. See the Beach Hazards Statement for more details.
&&
.FIRE WEATHER...
Mid-level moisture in southerly flow aloft will continue the
slight chance of showers and thunderstorms into this morning,
mainly for the for the mountains and deserts of San Bernardino
County. Little if any rainfall will reach the ground and any
thunderstorms that develop could produce dry lightning strikes and
locally gusty and erratic winds. Dry lightning strikes could
result in fire starts that have the potential for initially rapid
growth. The flow aloft is expected to become southwesterly by the
afternoon bringing drying aloft.
A low pressure system moving southward just off the coast of
British Columbia will strengthen the onshore slow across southern
California into the weekend. Southwest to west winds for the
mountains and deserts during the afternoon will strengthen for
Thursday through Saturday with gusts on Saturday of 35 to 45 mph
with gusts to 75 mph in the northern Coachella Valley below the
San Gorgonio Pass. Lowest humidity for the lower deserts will fall
to around 10 percent for Thursday afternoon and Friday afternoon
with near critical fire weather conditions for the deserts onto
the desert slopes of the mountains for Thursday and Friday
afternoon and early evening. The humidity for the deserts will
begin to recover on Saturday with lowest afternoon humidity of 20
to 25 percent.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Thursday evening for Orange
County Coastal Areas-San Diego County Coastal Areas.
Red Flag Warning until 11 AM PDT Today for Victor Valley-
Apple Valley-Lucerne Valley-Johnson Valley.
Extreme Heat Warning from 11 AM Today to 8 PM PDT Thursday
for San Diego County Deserts.
PZ...None.
&&
$$
PUBLIC/FIRE WEATHER...17
AVIATION/MARINE...Villafane
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