Yucaipa, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

383
FXUS66 KSGX 032108
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
208 PM PDT Sat May 3 2025


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.SYNOPSIS...

A strong area of low pressure will move into the region this
weekend into early next week. This will bring much cooler and
windier weather across inland areas along with increased chances
for precipitation across all of Southern California, where parts
of the deserts may see thunderstorms on Sunday. Rain chances
lower for areas near the coast by Monday with minimal rain chances
by Tuesday across SoCal. A building area of high pressure will
usher in warmer and drier weather by the middle and end of next
week.

&&

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

.SHORT TERM...A low pressure system will move into the region
through the weekend bringing late season rain and high elevation
snow to the area. As the low approaches, the marine layer has been
slow to mix out of the area and will likely remain in place over
much of the area through the overnight hours. Drizzle and light
rain are expected overnight at most locations west of the
mountains as the low approaches. Precipitations amounts are
generally expected to be light with a ensemble distributions
highlighting the best chances of 0.10 to 0.15 for most coastal
locations and up to 0.25 for the coastal slopes.

Winds will increase through the evening and overnight hours into Sunday
for the mountain and desert passes. A wind advisory has been
issued due to the likelihood of widespread 30 mph gusts, favored
locations like the San Gorgonio will likely see stronger gusts
with the strongest winds possibly approaching high wind warning
values.

Going into Sunday temperatures will remain cool for this time of
the year, with most locations west of the mountains 5 to 10
degrees below normal. Mountains will and the nearby desert will
have an increased chance of an isolated thunderstorm on Sunday,
which could produce an efficient rain event if one forms.
Confidence remains low, about 10% on the potential and location
for any thunderstorm on Sunday, but if one forms it could provide
between half an inch to an inch of rain in under an hour due to
the moist atmospheric profile.

Slight ridging is expected again on Monday between weak systems.
This should allow for a similar marine layer profile, but some
afternoon mixing bringing sunshine into the inland areas in the
afternoon with decreased chances of showers again.

Previous Discussion....

After Monday, a cooler trend sets in as a series of lows move
across the region along with increasing moisture in the lower and
mid levels. For early week, a low off the coast of San Diego will
become an open trough, sweeping across Baja and up through
Southern California, bringing the first chance for some
precipitation early Tuesday morning. At this time, chances remain
low for meaningful precipitation outside of the mountains where
about a 10-20% of some light rain and/or snow showers will be
possible at the highest elevations given snow levels above 8000ft.
Elsewhere, a deepening marine layer may lead to some morning
drizzle, especially for the coastal and valley areas. As the
trough moves up and out on Tuesday the cooler weather arrives,
with highs 5-10 degrees below normal west of the mountains and
slightly above normal for the deserts.

On Wednesday, a low off the coast will begin to push across Central
California, transitioning to a positively tilted trough on
Thursday. This trough will bring significantly cooler
temperatures, 15-20 degrees below normal for some spots, as well
as push some moisture into the area. At the same time, a deep low
pushes down from the north, arriving in southern Nevada by early
Friday morning. Models are in much better agreement today on this
next low, with better agreement on precipitation chances for late
week. Lows both Thursday and Friday in the low to mid 60s along
the coast and in the valleys, 40s and 50s in the mountains, and
60s to low 80s in the deserts. Snow levels will fall to around
6000-6500ft for both days, paving the way for some light snow
accumulations in the mountains. While models are in better
alignment with the upper level pattern for late week, QPF amounts
have generally trended down with the latest model runs, indicating
a higher-confidence in a lower-impact event at this point. Quite
a few things still need to be ironed out with the upcoming system
and how far south it manages to go, but currently the highest
chances (25-35%) for accumulations will be in the mountains. As
the low moves out of the area, a slow warming trend sets in with
weak ridging building and highs look to return to near or slightly
below normal by early next week.


&&

.AVIATION...
022030..Coasts/Valleys/Coastal Slopes...Low clouds based 1500-2500
ft MSL are still in place over most of the coastal basin and are
likely not going anywhere. Some inland areas may briefly scatter out
for a few hours, but not enough to mention any prevailing SCT for
TAF sites west of the mtns. Scattered -SHRA will move inland from
east to west after 02-03Z Sun, bringing localized reductions in cigs
and vis 3-6 SM. Bases will slowly rise through Sunday morning with
cigs above 2500 ft MSL expected in most locations.

Desert Mtn Slopes/Deserts...Southwest to west winds are starting to
push through the mountain passes and into the deserts. Winds peak
early Sunday morning with surface gusts 25-35 kt, locally up to 45
kt below the passes. MOD-STG up/downdrafts and areas of LLWS
possible over and east of the desert sleeps this afternoon and
evening. Winds remain elevated through the passes and downwind of
desert slopes through Sunday, but LLWS and up/downdrafts should be
less prevalent after 18z. SCT TSRA will develop over the deserts and
mtns north of San Diego County after 18z Sunday. Associated
up/downdrafts and vis restrictions will be possible with any storm
that develops.

&&

.MARINE...
Gusty west-northwest winds have started over the outer coastal
waters. Wind gusts around 25-30 kt over the outer coastal waters and
up to 20 kt over the inner coastal waters, along with combined seas
of 8-11 feet in the outer coastal waters and 7-9 feet in inner
coastal waters. Waves will be steep and wind-driven. Wave heights
peak Sunday morning and gradually lower Sunday afternoon into
Monday. A Small Craft Advisory remains in effect for the outer
coastal waters through 11 AM Sunday for the outer coastal waters and
from 11 PM tonight to 11 PM Sunday for the inner coastal waters.

&&

.BEACHES...
West swell of 8-11 foot swell with a 7-10 second period will
generate elevated surf and a high risk of rip currents starting
later today, bringing hazardous swimming conditions to all beaches.
Surf of 5 to 8 feet for San Diego County beaches, with local sets to
9 feet, and 3 to 6 feet for Orange County Beaches is expected. A
High Surf Advisory is in effect from 12z Sunday to 6z Monday. High
surf will come down by Monday morning in San Diego County. However,
building long period southwest swell may keep surf elevated for both
San Diego and Orange Counties (3-6 feet) through midweek.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory from 5 AM to 11 PM PDT Sunday for San Diego
     County Coastal Areas.

     Wind Advisory from 6 PM this evening to 6 AM PDT Sunday for San
     Diego County Deserts-San Gorgonio Pass near Banning.

PZ...Small Craft Advisory from 11 PM this evening to 11 AM PDT Sunday
     for Coastal Waters from San Mateo Point to the Mexican
     Border and out to 10 nm.

     Small Craft Advisory until 11 AM PDT Sunday for Waters from San
     Mateo Point to the Mexican Border Extending 10 to 60 nm out
     including San Clemente Island.


&&

$$

PUBLIC...Suk
AVIATION/MARINE/BEACHES...KW