Bonita, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

236
FXUS66 KSGX 151627
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
927 AM PDT Tue Apr 15 2025

.SYNOPSIS...
Onshore flow will strengthen and the marine layer deepen the next
few days spreading cooling inland with stronger and gusty west
winds for the mountains and deserts for Wednesday and Thursday.
There could be some patchy drizzle Wednesday morning and a slight
chance of showers for Thursday. A colder low pressure system from
the north could bring a chance of showers and slight chance of
thunderstorms on Friday. Then drier with warming for next weekend
with Sunday high temperatures returning to around average.

&&

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

.Morning Update...

A sharp inversion on this morning`s sounding yields a cloudy
coastal basin. Satellite trends show minimal movement and clearing
of the marine layer over the past few hours. Slow clearing is
likely with some areas near the foothills clearing first and
potentially near the northern Orange County coast as an area of
subsidence is noticed just offshore as clouds try to clear up a
bit. The forecast has been updated to reflect a slower clearing
trend into the afternoon with partial clearing at the immediate
coast. A similar story looks to unfold by tomorrow morning with
patchy drizzle west of the mountains and a deep marine layer
providing cloudy skies. Hi-res models continue to indicate
scattered showers for areas along and west of the mountains by
late Wednesday night through Friday with much cooler temperatures
and breezy conditions across the mountains and deserts.


.Previous Discussion (405 AM Tuesday)...

.SHORT TERM (Today through Thursday)...
A low pressure system to the west will move slowly toward the
east, weakening and move inland through southern California on
Wednesday night and Thursday. The marine layer has deepened to
2500 to 3000 feet with widespread low clouds over the coastal
waters extending inland across much of the San Diego County
valleys and spreading into the Inland Empire from the west and
south.

The coast and valleys will begin to cool today with greater
cooling spreading inland on Wednesday and Thursday. With the
cooling, high temperatures in some of the higher mountains on
Thursday will be as much as 15 to 20 degrees below average with
areas near the coast a few to around 5 degrees below average.
The marine layer will continue to deepen into Wednesday and
Thursday with the coastal low clouds spreading onto the coastal
mountain slopes. A deeper saturated cloud layer should be
favorable for more widespread drizzle for the coast into the
valleys for Wednesday morning. As that weakening low pressure
system moves inland through southern California for late Wednesday
night and Thursday, it will bring a slight chance of showers from
the coast to the mountains.

&&

.LONG TERM (Friday through Monday)...
On Friday, a cold low pressure system from the north has greater
potential to bring showers along with a slight chance of
thunderstorms. Cluster analysis shows greater precipitation
potential for those ensemble members that are more amplified with
the system and farther to the west with the track allowing for
greater entrainment of Pacific moisture.

Drier weather with warming is expected for the weekend with Sunday
high temperatures warming to around average, from the lower to mid
60s near the coast to the 70s for the Inland Empire with the lower
deserts in the mid to upper 80s.

&&

.AVIATION...
151600Z....Coasts/Valleys...Low clouds based around 2000-2500ft MSL
with tops near 3000ft have pushed 20-25 miles inland, encompassing
most coastal mountains, coastal regions, and inland valleys. VIS
restrictions are mostly limited to the mountain slopes where clouds
intersect terrain, but also some lower VIS of 2-4SM across the
Inland Empire this morning. Clouds should begin to retreat out of
the valleys and IE through 18z, with clouds lingering in coastal San
Diego County and at the beaches through 20-22z. Full clearly likely
won`t occur today before clouds develop and push inland again
tonight after 02z Wednesday with similar inland extent as seen this
morning by 08z Wednesday. -DZ once again possible Wednesday morning
with similar VIS restrictions.

.Mountains/Deserts...Periods of SCT-BKN clouds based 20,000ft MSL
through 12z Wednesday. Otherwise, light winds with typical westerly
flow through the mountain passes this evening and overnight.
Stronger west winds develop in the vicinity of the mountains
Wednesday afternoon and evening.

&&

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

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

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

&&

$$

PUBLIC...APR
AVIATION/MARINE...Zuber