Tustin Foothills, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

089
FXUS66 KSGX 112042
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
142 PM PDT Fri Apr 11 2025

.SYNOPSIS...
Warm weather will continue today with a subtle cooling trend
this weekend and into next week. The marine layer depth increases
slightly through the weekend with the focus of dense fog shifting
onto the coastal mesas. Cooling trend continues through next week
with breezy onshore flow in the mountains and deserts each
afternoon.

&&

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

Water vapor satellite imagery shows the thermal ridge axis has
shifted over Arizona, allowing heights to slowly fall through the
weekend. An upper level trough off the coast of OR today shifts
southward into the Central Valley through Sunday morning, stalling
north of the San Gabriel Mountains. This trough will be somewhat
influenced by a low pressure system 600 miles southwest of San
Diego, holding steady in Central California through Monday.

With the upper level ridge slowly moving east today, temperatures
region-wide will be 10-20 degrees above normal, and latest guidance
has pushed temperatures slightly higher compared to the previous
forecast package. In fact, at Palm Springs, the 50th percentile NBM
is 104 degrees and and 75th percentile is 106...given the record of
101 set back in 1990, there is a good chance at breaking a high
temperature record there today. This will be the last extremely hot
day as the aforementioned trough moves southward into California,
and temperatures cool around 5-8 degrees on Saturday. Morning fog
and low clouds will once again be present on the coast and over the
marine waters Saturday and Sunday mornings, with slightly further
inland coverage than what was observed this morning. A tightening
gradient over the region will be sufficient for some diurnally-
driven gustier winds Saturday afternoon, especially through mountain
passes and in the deserts. Gusts up to 35 mph in the deserts and
desert slopes of the mountains, with gusts up to 40 mph in the San
Gorgonio Pass.

Temperatures continue to cool Sunday as the trough attempts to
become a cutoff low, although models begin to differ at this point
with how the lows may propagate. Should a low manage to push
across Baja and into Southern California, some precipitation may
be possible. At this point, models indicate Monday night into
Tuesday as the main time frame, as well as Thursday night into
Friday. Given no long-range models are aligned with the upper
level pattern even for early week, confidence in any precipitation
next week is only around 10%. Instead, numerous lows and troughs
in the vicinity instills greater confidence in cooler temperatures
and highs falling below normal for areas west of the mountains by
Tuesday.

&&

.AVIATION...
112030Z...Coast...FG is lingering at the beaches and is set to
remain at the beaches until this evening, 02-04z Sat. Patchy FG
and low clouds with bases 300-500 ft will move inland throughout
the night, increasing in coverage and reducing VIS for coastal
slopes to 0-2 SM overnight. Bases rising over 500 feet MSL may
allow for improving visibility at the immediate coast by early
Saturday morning. Low clouds are expected to retreat to the beach
around 15- 17z Saturday.

Elsewhere...Gusts 25-30 kts expected this afternoon over the high
desert and around the Banning Pass. Otherwise, mostly clear skies
tonight and Saturday with VFR conditions.

&&

.MARINE...
Patchy fog over the marine waters may locally reduce visibilities to
less than 1 NM through tonight. Otherwise, no hazardous marine
conditions are expected through Monday.

&&

.BEACHES...
Surf 3-6 feet with sets to 7 feet are expected for most beaches this
afternoon through Sunday, bringing elevated risk for rip currents.


&&

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

&&

$$

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