Mesa Grande, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

006
FXUS66 KSGX 020359
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
859 PM PDT Sun Jun 1 2025

.SYNOPSIS...
Virga and light showers continue through tonight. Cooler weather
with highs near normal will occur through much of the week. There
is a 10-20 percent chance of showers and thunderstorms Tuesday
afternoon into Wednesday morning across the mountains and deserts
as an area low pressure enters the region. Dry with minor warming
for the latter half of the week.

&&

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

Evening update...
Thick mid and high cloud coverage today prevented any surface-
based convection from developing over our forecast area aside from
one brief heavier shower near Campo in San Diego County. The
center of the upper level low is currently moving into the lower
Colorado River Valley with some virga or light showers wrapping
around the back side into our mountains and deserts. This activity
will come to an end later tonight as the low continues to move
eastward. Otherwise patchy low clouds for the coastal areas and
muggy conditions overnight, especially in the low deserts.

Previous discussion...
Another weak area of low pressure will move down the coast on
Monday. PWAT values lower as our system from today departs, but
humidity will stick around. High temperatures will be similar in
most places on Monday, but a few degrees cooler closer to the
coast and valleys. The low pressure system moves inland over our
region by Tuesday, which will pull in subtropical moisture and
increased instability once again with ensemble models showing
CAPE near 500-700 J/kg. NBM precipitation chances near 15-25%
across the mountains and deserts remain sufficient for this
forecast. Forecast timing on this is moderate with latest thinking
as notable chances from Tuesday morning through Tuesday night.

The weak weather system will depart late Tuesday, as a troughing
pattern over area remains from Wednesday through later in the
week. This pattern will keep us dry with highs near seasonal
averages. Models depict our region between two large areas of high
pressure, one over the Pacific and the other over Mexico. Ensemble
model guidance is leaning toward the area of high pressure over
Mexico expanding closer to our region, which will bring slightly
warmer weather by next weekend.

&&

.AVIATION...
020400Z...Coasts/Valleys...SCT-BKN mid level clouds at 6,000-
13,000ft MSL continue to stream overhead but will gradually decrease
in coverage by Monday morning. Meanwhile, patchy low clouds based
1,000-1,500ft MSL are slowly increasing in coverage off the coasts.
These will continue to build and push ashore in the next several
hours, bringing CIGs to the coastal TAF sites by 07-09z. These
clouds will move about 15 mile inland by 12z MOnday, with VIS
obscurations where clouds intersect higher terrain, with better
visibility for the immediate coast. Clouds clear by 16-17z Monday
morning but may linger offshore into the afternoon. Marine layer
clouds look to surge back inland fairly early Monday evening, as
early as 00-03z Tuesday.

Deserts/Mountains...SCT-BKN mid level clouds near 10,000ft will
gradually clear out by Monday morning, giving way to mostly clear
skies through Monday night.

&&

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

&&

.BEACHES...
A long period south swell builds into the region today, leading to
elevated surf for south and southwest facing beaches of 4 to 6 feet
with sets to 7 or 8 feet possible. This will result in higher rip
current risk and locally hazardous swimming conditions. Surf peaks
Monday and gradually diminishes Tuesday through Wednesday. A Beach
Hazard Statement is in effect and contains more information.

&&

.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 afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...SS/APR
AVIATION/MARINE/BEACHES...Munyan