645
FXUS66 KSGX 112348
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
448 PM PDT Sat Jul 11 2026

.SYNOPSIS...
Near normal temperatures expected this weekend. Thunderstorm
chances over the mountains and locally into the deserts each
afternoon Sunday through much of the forecast period. Above
average high and low temperatures return early to mid next week.
Coastal flooding will impact beaches Sunday through Tuesday with
evening high tides exceeding 7 feet.

&&

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


...UPDATED AVIATION DISCUSSION...

Low clouds have scattered out of coastal San Diego County, and
will be a bit more stubborn in Orange County, partially clearing
this afternoon. Elsewhere, high clouds are streaming in from the
south as an area of showers crosses over the northern portion of
Baja California. This may bring greater cloud cover across
portions of San Diego County this afternoon and early evening. The
marine layer remains thinner, and will come in later tonight into
the mid morning for coastal areas. This low cloud pattern looks
to continue over the coming days.

The high pressure system that has brought the hotter weather has
moved off to the northeast. This will help bring temperatures
closer to normal, though parts of the mountains and high desert
will be about 5 degrees above average. Models indicate humidity
and PWAT values increasing later today into Sunday as the ridge
moves over the Intermountain West. The hot dry air mass will
struggle some to produce accumulating rainfall on Sunday, so
slight chances are in the forecast for mountain regions into
portions of the high desert. The high pressure system expands and
moves into the northern plains by Monday as a trough offshore
deepens. These two system will create to better funnel this
monsoonal moisture into the desert southwest as PWATs/humidity
peak, bringing the greatest chance for storm activity over the
short term period. The mountains and deserts have the greatest
chances (35-60% chance) to see bouts of heavy rainfall, lightning,
and small hail Monday afternoon and evening. Confidence is still
low on how far west this moisture and instability will move during
this time period, so chances for any storm development west of
the mountains is currently at or below 10 percent.

By Tuesday, models are in fair agreement of the high over the
Great Plains shifting further to the east, displacing some of the
moisture over our region. This will aid in a lower chance (20-35%)
of showers and thunderstorms over the northern mountains and
deserts. Models show the high may retrograde back to the west by
Wednesday into the end of the week, which would provide a greater
storm chance to inland areas.

With the incoming monsoonal moisture and thunderstorm threat,
there will also be higher humidity and hot weather! We all will
start to feel greater humidity from the coast to the deserts by
Sunday, which will last into much of the upcoming week. Along
with this, hotter weather will return by the middle of the week
(Tuesday - Thursday) for many areas that saw it this past week,
with a larger emphasis on valleys west of the mountains. NBM shows
high temperatures well into the 90s east of Interstate 5 in
Orange County and east of Interstate 15 in San Diego County, with
highs near 100-105+ across the Inland Empire. With these
temperatures, humidity, and warmer overnight low temperatures,
HeatRisk will be higher, so please plan ahead!

&&

.AVIATION...
120000Z....Coast/Valleys...Increasing high clouds AOA 15kft MSL this
evening, with high clouds spreading into much of the region
overnight. Patchy low clouds will develop again this evening and
move inland, likely around 900-1200ft MSL, but may be less
widespread given the influx of high clouds. Low clouds will move
into San Diego County generally after 03z, and up into Orange County
after 08z. VIS restrictions where stratus intersects terrain. Low
clouds will clear back to the coast around 16z, but high clouds will
prevail through the afternoon and evening on Sunday.

.Mountains/Deserts...Increasing mid/high clouds AOA 15,000 ft MSL
today and tomorrow and generally unrestricted visibility. There is a
slight chance of thunderstorms over the mountains Sunday afternoon,
with any storm capable of gusty and erratic winds and low visibility
due to heavy rain.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from Sunday morning through Tuesday
     evening for Orange County Coastal Areas-San Diego County
     Coastal Areas.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...Zuber

NWS San Diego (SGX) Office