Mesa Grande, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

419
FXUS66 KSGX 160413
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
913 PM PDT Sun Jun 15 2025

.SYNOPSIS...
A gradual cooling trend starts Monday and continues through most
of the week with the possible exception of Wednesday. Night and
morning low clouds and fog can be expected each day along the
coast, reaching into portions of the valleys for the middle to end
of the week. Breezy west winds across the mountains and deserts
each afternoon and evening, strongest on Monday.

&&

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

.UPDATE...
No significant changes from the forecast. Temperatures this
afternoon over-preformed for many location, especially along the
15 corridor in San Diego County, where highs generally ranged from
90-102 due to a brief reprieve from the seabreeze and wind shift
to the south. Limited records were broken today despite the
abnormally hot weather, even the 117 at Palm Springs fell short of
the record of 120 degrees set back in 2021. Temperatures peaked
today with strong ridging over the area, but a flattening ridge
into mid week will promote a slow cooling trend, with highs
generally still above normal for mid June. Clusters continue to
support this pattern, with troughing returning by the weekend to
cool temperatures further. Unfortunately, there remains no
significant precipitation on the horizon.

.PREVIOUS FORECAST FROM 119 PM...
Temperatures at 1 PM were running mostly 5 to 10 degrees warmer than
1 PM yesterday across the area. Widespread moderate HeatRisk is
impacting the inland valleys, mountain foothills, and High Desert
today, with moderate to locally major HeatRisk in the low desert.
Make sure you`re staying hydrated and seeking shade if you`re
spending time outdoors. If possible, avoid strenuous outdoor
activity during the hottest part of the day (through 5pm). The ridge
of high pressure over us today will begin to flatten Monday as an
upper level trough moves inland across the West Coast. That will
kick off a gradual cooling with highs Monday a few degrees cooler
than today and additional cooling into Tuesday. Even with highs
being knocked down a few degrees, they will remain 3 to 7 degrees
above average Tuesday.

In addition to a few degrees of cooling, onshore flow will
strengthen. That will bring breezy west winds to the desert mountain
slopes, below the passes, and into the deserts during the afternoons
and evenings. Strongest winds are expected Monday with gusts 30 to
45 mph, locally up to 50 mph through the San Gorgonio Pass.

Low clouds are expected to remain persistent each night and morning
for the coast early this week, with areas of locally dense fog
possible. The marine layer is expected to deepen for the middle to
end of next week as a more amplified trough of low pressure
approaches the West Coast.

Global ensemble clusters show a brief rebound in the ridge for
Wednesday, which will bring a few degrees of warming to inland
areas. NBM chances for the Inland Empire to exceed 100 degrees is 30
to 60 percent, with the higher chances in the eastern portions of
the Inland Empire. In the low desert, NBM has a 60 to 80 percent
chance of high temperatures exceeding 110 degrees. In the High
Desert chances of exceeding 100 degrees are 70 to 80 percent. The
warming on Wednesday will be short lived as there is good ensemble
agreement in a more amplified trough moving into the Pacific
Northwest Thursday through the weekend. While there is still some
uncertainty in the finer details cooler conditions, increased winds,
and a deeper marine layer can be expected for the end of the week.
There is high confidence in dry conditions with this passing
trough.

&&

.AVIATION...
160330Z....Coast/Valleys...Low clouds are redeveloping offshore this
evening. These are expected to push onshore after 06Z tonight,
initially across southern coastal San Diego County, then pushing
northward and inland to 10-15 miles through 13Z. Bases may start out
around 500-800 ft MSL but then lower to 300-600 ft MSL, with vis 1-4
SM for coastal TAF sites. Clouds clearing to beaches 16-17Z Mon,
followed by clear skies. Low clouds with similar bases and vis
expected to develop again after 06Z Tue, but with patchier coverage.

.Mountains/Deserts...FEW-SCT high clouds and mostly unrestricted
VIS prevail through Monday. West winds strengthening after 18Z Mon,
with wind gusts 20-30 kts, locally near 40 kts through the San
Gorgonio Pass, leading to MOD UDDFS 21Z Mon-08Z Tue.

&&

.MARINE...
Wind gusts up to 20-25 kts possible in the outer waters Monday
afternoon near San Clemente Island. Otherwise, no hazardous marine
conditions are expected through Thursday.

&&

.BEACHES...
A 3 foot southerly (190 degrees) swell at 17-18 seconds will
continue to produce elevated surf of 3 to 6 feet with local sets up
to 7 feet, primarily for Orange County and northern San Diego County
beaches. A Beach Hazard Statement remains in effect through late
this evening. Swell and surf heights wane late tonight into Monday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 11 PM PDT this evening for Orange
     County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...Zuber
AVIATION/MARINE/BEACHES...CSP