Riverside, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

420
FXUS66 KSGX 092026
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
126 PM PDT Mon Jun 9 2025

.SYNOPSIS...
Shallower marine layer each morning through mid-week with well
above normal temperatures for inland areas and deserts, peaking
Tuesday and Wednesday. A slight cool down is expected for the end
of the week before temperatures increase again for the weekend.

&&

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

Light drizzle was observed this morning for parts of San Diego
County but satellite showed the marine layer quickly burned off for
valleys and inland areas, much quicker than previous mornings. While
the coming days will feature a shallower marine layer with less
inland extent as high pressure builds in, low clouds will persist
along the immediate coastline likely through at least mid week.

Water vapor imagery shows a shortwave trough over the southern half
of California with amplifying high pressure to the southwest. This
troughing is helping to limit the influence of the high, with
temperatures this afternoon expected to be very similar to Sunday.
The shortwave won`t hang around for long as it moves down into
southwest New Mexico on Tuesday, and high pressure builds over
SoCal. Once again, the marine layer will moderate temperatures along
the coastline for Tuesday with strong onshore flow, but further
inland areas will experience a decently quick warm up. The valleys
and even the mountains may reach close to 10 degrees above normal,
while the deserts will see highs potentially encroaching on or
exceeding 110F in some desert spots. Moisture from the southeast may
move up into the Coachella Valley and lower deserts both Tuesday and
Wednesday, and depending on if it is mixed out in time, may curb
some of the warm up with the height increases. While the pattern
still favors significant warming in these areas, the influence of
the moisture may place a ceiling on highs both afternoons. In any
case, temperatures for the Coachella Valley and lower deserts peak
both Tuesday and Wednesday, with the inland areas and mountains
likely to peak Tuesday.

Late Wednesday an upper level low along the coast of Canada looks to
move southward towards Graham Island, flattening the high a bit and
zonal flow aloft looks to prevail over the region Thursday and
Friday. Around the same time, the weaker high will slowly move
eastward into Baja before reaching the Four Corners early Saturday,
with ridging quickly rebuilding. A slight cool down is expected for
the latter half of the week, but a return to ridging this weekend
looks to push highs back to well above normal, potentially even
warmer than earlier in the week. This pattern looks to holdover into
early next week with no meaningful cooldown or precipitation in
sight, a significant shift from just a few days ago where it seemed
troughing would prevail for the weekend.

&&

.AVIATION...
092022Z....Coast/Valleys...Low clouds reached into the western and
southern parts of the Inland Empire last night. Clouds have cleared
inland areas, but only partial and/or intermittent clearing at the
immediate coast. Probability of BKN-OVC clouds all day today at KSAN
is around 80-90%. Clouds will push inland after 01Z tonight into
Tuesday, but not as far inland as this morning. Bases would be
around 500-1000 feet MSL with some vis reduced over higher coastal
terrain.

Mountains/Deserts...Mostly clear skies and unrestricted VIS today
and tonight.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...Zuber
AVIATION/MARINE...Small