Jamul, California Weather Forecast Discussion

785
FXUS66 KSGX 282042
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
142 PM PDT Sun Sep 28 2025
.SYNOPSIS...
Slight chances of showers and thunderstorms over the mountains
this afternoon, then dry weather for the remainder of the week.
High temperatures remain well below normal with a deep marine
layer through Tuesday. Gradual warming expected Wednesday through
the end of next week with a shallower marine layer.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Geocolor satellite shows mostly sunny conditions across the region
as most of the marine layer clouds have dissipated, as of 1:30 PM.
Cumulus clouds have developed over mountain ridges, although mostly
too shallow for precipitation, with only a 10-15% chance for a stray
shower this afternoon. Marine layer clouds will start to develop
late this evening and cover the coastal basin tonight.
For Monday, the upper level trough that delivered unsettled weather
this weekend will have lost all of its influence on the weather in
So Cal. An extensive trough will set up off the coast of Washington,
deepening and generating an upper shortwave trough that will lift
through Nor Cal, cooling off our temperatures by a few degrees
Tuesday. High temperatures are expected to stay in the upper 70s and
lower 80s for inland valleys and in the Inland Empire. As the
shortwave lifts, our region will start to feel some mild influence
of a ridge building to our south, allowing temperatures to increase
a few degrees - to near average - later this week. This "warm-up"
will remain modest as seasonable onshore flow continues as the
broader trough to the north maintains its influence. After Friday,
models agree that the trough will move eastward though diverge
however, on the southward reach of the trough, leading to a 12
degree spread between the NBM 10th and 90th percentile max
temperatures for inland areas. Either way, there is moderate
confidence temperatures remain within a few degrees of average,
whether above or below.
This week, the marine layer will stay deep enough to cover the
coastal basin through Tuesday morning. The marine layer will become
shallower Wednesday through Friday mornings only reaching into
inland areas of San Diego and Orange Counties.
&&
.AVIATION...
282000Z....Coasts/Valleys/Foothills...Low clouds with bases 1500-
2500 ft MSL develop along coastline after 03Z Mon, starting in San
Diego County then moving north and into inland valleys, including
KONT/KSBD, by 12Z Mon. Vis restrictions of 2-4 SM BR where low
clouds intersect higher coastal terrain. Low clouds and any vis
restrictions expected to scatter out 17-19Z Mon. Low clouds could
locally linger at beaches into Mon afternoon.
Mountains/Deserts...10-20% chance iso -SHRA along with 10% chance
for TSRA mostly over the mountains through 00Z. Otherwise, VFR
conditions with cu based 7-10k ft MSL over mountains in the
afternoon. Cu will clear after 00Z Mon, with mostly clear skies
expected Mon.
&&
.MARINE...
No hazardous marine conditions are expected through Friday.
&&
.BEACHES...
South swell from Tropical Cyclone Narda at 4-5 feet with a period of
12-14 seconds will produce elevated surf and a high rip current risk
through Tuesday. Surf of 4-7 feet with sets 8 feet on south facing
beaches expected. Strong longshore currents will impact all beaches.
Surf will begin to decrease Wednesday with strong rip currents
lingering into Thursday. More information can be found in the Beach
Hazards Statement.
&&
.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 Tuesday evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.
PZ...None.
&&
$$
PUBLIC...Westerink
AVIATION/MARINE/BEACHES...CO

NWS SGX Office Area Forecast Discussion