Grossmont, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

904
FXUS66 KSGX 282150
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
150 PM PST Fri Nov 28 2025

.SYNOPSIS...
Relatively quiet weather expected through early next week with
weak offshore winds Saturday and again Monday. Night and morning
coastal low clouds and fog will increase in coverage and spreading
a little farther inland each night through the weekend. Next
potential storm system will occur Wednesday into Thursday, but
confidence in rainfall continues to be low, with chances for dry
weather and yet another round of offshore flow mid week
increasing.

&&

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

The ridge that had previously been overhead has been flattened out
but a shortwave trough digging from the Pacific Northwest into the
Great Basin this weekend. Ultimately, the result of this trough will
be minimal, with weak offshore winds in the deserts and mountain
passes, with onshore flow dominating for the coasts and valleys. The
onshore flow and a weak coastal eddy tonight will help clouds fill
in better tonight, likely pushing ashore overnight, with patchy fog
expected along the coasts, particularly coastal mesas and
portions of western valleys. Otherwise, relatively benign weather
expected through the weekend with mostly clear skies and
temperatures within 5 degrees of seasonal norms. Yet another
inside slider digs through the Great Basin Sunday into Monday,
restrengthening the offshore gradient and leading to another round
of offshore winds. This event looks to be a touch stronger than
Saturday`s offshore flow with easterly/northerly winds extending
into the inland valleys, however, the event is still rather weak.

The timing of the next disturbance is in the Tuesday-Wednesday
window, though a great deal of uncertainty remains in the depth of
the trough, with reasonable spread in the ensembles varying from
a trough deep enough to bring showers to the area, to a shallower
trough that could bring another round of offshore flow with no
precipitation. A driving factor in the evolution of this trough
and it`s forecast depth is rogue cut-off low well off the southern
California coast early-mid next week. If the cut-off low stays
close and interacts with the trough, precipiation chances become
more likely and offshore flow will be more limited. Ensembles are
fairly split in precipitation, with about a 50/50 chance for
showers. Even still, should the rainy solution pan out, rainfall
totals will be light, generally 0.1" or less, locally up to 0.25"
on the coastal slopes. Snow levels between 6500-7000ft, so a few
flakes are possible in the mountains if precipitation occurs. The
most certain aspect of this forecast will be temperatures about 5
to 10 degrees below average.

&&

.AVIATION...
282145Z....Coasts/Valleys...Low clouds will move ashore tonight (45-
60% chance) after 02z Sat with bases slightly higher than this
morning, 700-1200ft MSL. Clouds will push 5-10 miles inland.
Localized VIS reductions down to 4-6SM, with 1-3SM for elevated
coastal terrain. Any low clouds should begin clearing to the coast
around 16-17Z.

.Mountains/Deserts...VFR conditions expected through the TAF
period.

&&

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

&&

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

&&

$$

PUBLIC...Munyan
AVIATION/MARINE...Zuber