Mountain Center, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

985
FXUS66 KSGX 061630
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
930 AM PDT Fri Jun 6 2025

.SYNOPSIS...
A deep marine layer persists for coastal and inland areas through
Saturday, with a shallower marine layer and valley/inland fog Sunday
through much of next week. Temperatures warm through the weekend,
peaking Monday and Tuesday, before a slow cooldown into the end of
the week.

&&

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

.UPDATE...
No significant shift in the forecast from the previous package.
Confidence has increased slightly for morning drizzle to occur again
Saturday morning before the marine layer becomes more shallow
thereafter. Warmer weather prevails this weekend and into next week,
peaking Monday and Tuesday. Zonal flow aloft redevelops by
Wednesday, with slight troughing by the end of the week, indicating
a slow cooldown into next weekend.

&&

.PREVIOUS FORECAST FROM 224 AM...

Marine layer low clouds continue to spread into the inland valleys
this morning with mostly clear skies elsewhere. Light
precipitation has been reported in northwestern San Diego County
this morning with patchy drizzle likely to continue through mid
morning. Otherwise a very June Gloom day along the coast and high
temperatures near normal today. Some lingering mid-level moisture
will be in place for some scattered cumulus development over the
mountains and a 10% chance of showers over the highest peaks of
the San Bernardino Mountains during the afternoon.

Surface high pressure will slowly build in from the southeast on
Saturday with a cut-off low lingering off the Central CA coast.
A warming trend will begin, continuing into early next week as the
upper high shifts westward to our south and then amplifies to our
southwest. This will also cause the marine layer to become more
shallow, with low clouds covering only the coastal areas and far
western valleys by Monday. For Tuesday, there is a 15-20%chance
of high temperatures of 100 degrees or more in the far inland
portions of the Inland Empire and a 25-50% chance in the lower
elevation portions of the high desert. There is a 10-25% chance of
highs of 110 or more in the low desert, locally up to 40% at Palm
Springs. In general highs will be around 5-10 degrees above
normal Monday and Tuesday with moderate HeatRisk in the inland
valleys and deserts.

The upper level high begins to weaken on Wednesday as a short wave
trough moves by to the north, then the high shifts westward with
an upper trough developing along the West Coast Thursday and
Friday for greater cooling and a deepening of the marine layer.
Some ensemble members show a much weaker trough and therefore less
cooling during this period, but it only accounts for about 13% of
the ensemble space.

&&

.AVIATION...
061530Z....Coast/Valleys...Low clouds based 1000-2000 ft MSL with
tops to 2500-3000 ft are in place over most of the coastal basin.
Areas of -DZ bringing periodic vis restrictions 2-5 SM in BR and
lower cigs to 700-900 ft MSL. Clouds gradually clearing from inland
areas, coastal Orange County, and coastal northern San Diego County
16-19Z. However, coastal areas from KCRQ southwards and to about 10
miles inland in San Diego County will likely remain BKN all day once
again. Clouds will quickly push into inland San Diego County after
00z Sat followed by Orange County and the IE after 04z. However,
there is a 30% chance that the IE does not fill in completely due to
a slight lowering of the cloud layer. There is a 40% chance for -DZ
again after 10Z Sat.

Mountains/Deserts...Mostly clear through Friday night. FEW-SCT
cumulus based at 10,000ft MSL will form 19Z Fri-01Z Sat over
northern mountains and high desert.

&&

.MARINE...
No hazardous marine conditions are expected today through Tuesday.

&&

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

&&

$$

PUBLIC...Zuber
AVIATION/MARINE...Westerink