960
FXUS66 KSGX 110413
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
913 PM PDT Sun May 10 2026

.SYNOPSIS...
Above average temperatures will prevail through much of the forecast
period. The warmest conditions are expected Monday, with a
gradual cooling to within a few degrees of normal Tuesday through
Friday. Night and morning low clouds and fog will be present each
day along the coast and into portions of the valleys. A gradual
warming trend is possible next weekend.

&&

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

...New Aviation Discussion for 06z TAF Package...

Warming will continue into Monday with an additional 3 to 7
degree increase compared to today. This will bring high
temperatures 10 to 20 degrees above average for inland locations
Monday and 5 to 8 degrees above average along the coast. Areas of
widespread moderate HeatRisk are expected in the Inland Empire and
High Desert with major HeatRisk in the low deserts through
Monday. Make sure to stay hydrated and seek shade when possible if
working outdoors.

Temperatures on Tuesday will cool 5 to 12 degrees compared to Monday
as the ridge aloft weakens and is pushed east by a shortwave trough
passing from our southwest. The passing shortwave will strengthen
onshore flow for Tuesday and Wednesday, increasing south to
southeast winds in the deserts on Tuesday and westerly winds from
the mountain slopes into the deserts on Wednesday. This passing
feature is not expected to have moisture associated with it so dry
conditions will prevail.

For Wednesday through Friday, most ensemble clusters are showing a
weak troughing pattern prevailing over the US West Coast. This will
maintain marine layer low clouds and fog for the coast and valleys
and take high temperatures back to within a few degrees of normal.
For next weekend, the majority of ensemble clusters keep the upper
level pattern weakly troughy to zonal, with only 10 percent of
solutions showing weak ridging developing by next Sunday. The
forecast for next weekend follows the NBM which indicates a gradual
warm up for Saturday and Sunday. There remains low confidence in
just how warm it will get with the deterministic NBM again
representing the highest percentiles of most other ensemble
guidance.

&&

.AVIATION...
110600Z...Coast/Valleys...Low clouds are poised to move up to 10-15
miles inland overnight. There is lower confidence on timing clouds
remain offshore this evening. Bases near 1000-1300ft MSL will move
onto the coast, slowly falling through the night closer to 700-900ft
MSL by 10-13z. Lower confidence in clouds reaching KONT (20%)
compared to Sunday morning. VIS reductions 4-6SM in BR for higher
coastal terrain, with locally 1-3SM for interior valleys. Bases
likely lifting back above 1000ft MSL by 14-15z, with full scattering
back offshore by 16-17z. Another round of low clouds expected again
Monday evening with similar bases.

Mountains/Deserts...SKC and VFR through Monday.

&&

.MARINE...
No hazardous marine conditions are expected through Thursday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 10 AM to 8 PM PDT Monday for San Bernardino
     and Riverside County Valleys-The Inland Empire.

     Extreme Heat Warning until 8 PM PDT Monday for Coachella Valley-
     San Diego County Deserts-San Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC...CO
AVIATION/MARINE...Zuber