Grossmont, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

334
FXUS66 KSGX 132035
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
135 PM PDT Sun Apr 13 2025

.SYNOPSIS...
Minor cooling Monday followed by more significant cooling for the
second half of the week down to 10-20 degrees below normal on
Friday. Low clouds and fog will continue across the coastal areas
and western valleys each night and morning through the middle of
next week with marine layer drizzle possible Tuesday morning.
There is a 10 to 15 percent chance of light precipitation over the
mountains Monday night, and then a 15 to 30 percent chance for
the mountains westward at times Thursday night through Saturday.

&&

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

Satellite shows that clouds have generally cleared to the beaches
today where they will likely linger through the evening before
pushing inland again tonight. Temperatures hold fairly stagnate
today and tomorrow with weak ridging building in and highs generally
near normal to slightly above normal west of the mountains and 5-10
degrees above normal for areas east of the mountains. AM low
clouds and fog are once again expected on Monday with similar
inland extent and visibility restrictions as seen this morning.
After Monday, a cooler trend sets in as a series of lows move
across along with increasing moisture in the lower and mid levels.
For early week, a low off the coast of San Diego will become an
open trough, sweeping across Baja and up through Southern
California, bringing the first chance for some precipitation early
Tuesday morning. At this time, chances remain low for meaningful
precipitation outside of the mountains where about a 10-20% of
some light rain and/or snow showers will be possible at the
highest elevations given snow levels above 8000ft. Elsewhere, a
deepening marine layer may lead to some morning drizzle,
especially for the coastal and valley areas. As the trough moves
up and out on Tuesday the cooler weather arrives, with highs 5-10
degrees below normal west of the mountains and slightly above for
the deserts.

On Wednesday, a low off the coast will begin to push across Central
California, transitioning to a positively tilted trough on
Thursday. This trough will bring significantly cooler
temperatures, 15-20 degrees below normal for some spots, as well
as push some moisture into the area. At the same time, a deep low
pushes down from the north, arriving in southern Nevada by early
Friday morning. Models are much more confident today on this next
low, with better agreement on precipitation chances for late week.
Lows both Thursday and Friday in the low to mid 60s along the
coast and in the valleys, 40s and 50s in the mountains, and 60s to
low 80s in the deserts. Snow levels will fall to around
6000-6500ft for both days, paving the way for some light snow
accumulations in the mountains. While models are in better
alignment with the upper level pattern for late week, QPF amounts
have generally trended down with the latest model runs, indicating
a higher-confidence but lower-impact event at this point. Quite a
few things still need to be ironed out with the upcoming system
and how far south it manages to go, but currently the highest
chances (25-35%) for accumulations will be in the mountains. As
the low moves out of the area, a slow warming trend sets in with
weak ridging building and highs look to return to near or slightly
below normal by early next week.


&&

.AVIATION...
132025Z...Coasts/Valleys...Low clouds based 800-1200 ft MSL with
tops near 2700 feet at the coast and locally inland, beginning to
push inland again after 02Z Mon, reaching the KONT area after around
10Z Monday morning. Low clouds retreating to beaches 16-18Z Mon, but
patchy clouds will linger along parts of the immediate coast through
the day.

Elsewhere...Mostly clear skies with VFR conditions. Local
west wind gusts 25-35 kt over the mountains into the passes and
deserts late afternoons and evening.

&&

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

&&

.BEACHES...
Surf 3-5 feet is expected through Sunday with sets to 6 feet along
west facing beaches, bringing a high risk for rip currents.

&&

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

&&

$$

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