Guatay, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

938
FXUS66 KSGX 301550
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
850 AM PDT Wed Apr 30 2025

.SYNOPSIS...
Spring weather will continue, with coastal clouds during nights
and mornings filling the coastal basin. A weak low pressure
system will bring a slight chance of showers and thunderstorms on
Thursday afternoon for the San Bernardino County mountains and
adjacent deserts with a slight chance of showers for the same
areas on Friday afternoon. A stronger low pressure system from the
northwest will bring cooler, windier and wetter weather late
Saturday into Monday. Warmer and drier weather will gradually move
in by the middle of next week.

&&

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

Low clouds and fog spread inland overnight and nearly all of the
coastal basin got shrouded. The marine inversion is pretty strong
and the stratus deck is pretty solid, suggesting that clearing at
the coast might be partial at best today. Some high clouds hint at
the upper level low that has begun to form to our north. This will
develop today and Thursday over SoCal. That will maintain our
deep marine layer, with a similar low cloud coverage the next two
nights and mornings. It will also bring a curious chance of
showers and thunderstorms in our northern zones, the high desert
and San Bernardino Mountains, during the afternoons Thursday and
Friday. The moisture and instability in the northeast quadrant of
the upper low justify that small chance. The low moves east
Friday, but lingering moisture continues that small chance of
precip in that area. Temperatures will be a couple degrees lower
with less sunshine and more marine influence, especially near the
coast, but Friday should be a little warmer. The bigger storm
system moves down the coast Saturday. Initially, it will bring
strong onshore winds by Saturday afternoon, especially for the
mountains, deserts and coastal waters. Top gusts in the top spots
through mountain passes should exceed 60 mph. Then comes the
precipitation Saturday evening. Winds decrease only a little
Sunday while the greatest precipitation appears focused on
Sunday. A few thunderstorms should enter the mix Sunday afternoon.
Storm total precip is not impressive, less than 0.50 inch for the
top mountain spots. Snow levels will drop rapidly to about 5,000
feet by sunrise Sunday. Several inches of snow are likely at
elevations above 7,000 feet. Several shortwaves will rotate within
this upper low that cuts off from the jet stream. These will
dumbell for a couple days while the moisture gradually decreases.
For most areas, showers will decrease and end Sunday night, but
the dumbell effect will continue to provide energy to work with
the decreasing moisture to prolong precip chances through Monday
especially over the mountains and in southern San Diego County.
Some guidance indicates these chances of mountain showers
continuing through Tuesday. Such is the nature of closed lows that
cut off from the jet stream, they are content to sit and spin in
one place for a while, and tend to overstay their welcome. By
midweek, the low should weaken and move east enough to forecast a
warming and drying trend.

&&

.AVIATION...
301530Z....Coasts/Valleys...Low clouds based 1000-1500 feet MSL with
tops around 2500 feet MSL have filled most of the coastal basin.
Visibility 2-5 SM for most of the Inland Empire with coastal slopes
of the mtns shrouded in FG. Low clouds will clear to the coast by 18-
20z. 25% chance that cigs remain BKN through the afternoon along the
San Diego County coast and over nearshore waters. Regardless of
whether scattering occurs, low clouds will reinvade coastal sites
after 02z this evening and quickly push inland. Bases of around 1000-
1500 ft MSL, will remain around the same height. Vis restrictions
possible (2-5 SM) for the Inland Empire and FG where the cloud layer
intersects coastal slopes of the mtns. Similar clearing pattern
expected Thursday morning with low clouds scattering to the
coastline by around 18z. Low clouds may linger at the beaches and
over nearshore waters again Thursday afternoon.

Mountains/Deserts...SCT high clouds through Thursday morning.
Isolated thunderstorms after 20z Thursday in the High Desert and San
Bernardino County Mtns. If any storms develop, associated vis
restrictions and up/downdrafts will be possible.

&&

.MARINE...
No hazardous marine conditions are expected through Friday. Gusty
west to northwest winds will develop over the coastal waters this
weekend, with strongest winds Saturday night and Sunday. Peak gusts
of 25 to 30 kt expected. Gale force winds are possible, with a 25
percent chance of winds reaching at least 34 kt in the outer coastal
waters near San Clemente Island Saturday night into Sunday morning.

&&

.BEACHES...
Elevated surf of 3 to 6 feet with sets to 7 feet will occur through
today. Highest surf occurred on south facing beaches today and will
gradually lower tonight into tomorrow. Strong rip currents are
expected, especially today.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through this evening for Orange County
     Coastal Areas.

PZ...None.

&&

$$

PUBLIC...MM
AVIATION/MARINE/BEACHES...KW