Bonita, California Weather Forecast Discussion

551
FXUS66 KSGX 051056
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
356 AM PDT Fri Sep 5 2025
.SYNOPSIS...
Generally seasonal temperatures will prevail through the weekend
with decreasing chances for afternoon thunderstorms for the
mountains and deserts on Saturday with dry weather for Sunday.
A low pressure system will move slowly inland into the western
states next week bringing drying and a gradual cooling trend.
With the cooling, high temperatures on Wednesday and Thursday will
be a few degrees below average near the coast to as much as 10 to
15 degrees below average for the mountains, high desert, and
inland valleys.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Sunday)...
Late Thursday evening, outflow from thunderstorms spread westward
into the deserts and mountains in San Diego County and
northwestward across the Coachella with the strongest gust to 46
mph at Thermal at 10:32 PM. This outflow pushed dewpoints in the
lower deserts mostly into the lower 70s.
Coverage and intensity of thunderstorms for this afternoon for the
mountains and deserts is expected to be similar to Thursday
afternoon with the greatest coverage and rainfall amounts over the
mountains of San Diego and Riverside Counties with the highest HREF
90th percentile hourly rainfall of around 0.9 inch for this
afternoon and around 0.5 inch for Saturday afternoon with lesser
coverage and amounts. Dry weather is expected for Sunday.
Coverage of night and morning coastal low clouds will gradually
increase through the weekend with low clouds over the coastal
waters spread locally inland into coastal areas late each night.
High temperatures for today may be a few degrees cooler than
Thursday followed by a degree or so of warming on Saturday and
another degree or so of warming on Sunday. High temperatures on
Sunday are expected to be near average at the coast to a few
degrees below average for inland areas, ranging from the 70s near
the coast to the 90s for the Inland Empire with 100 to 104 for
the lower deserts.
&&
.LONG TERM (Monday through Thursday)...
A low pressure system will move slowly inland into the western
states next week bringing drying a gradual cooling trend. With the
cooling, high temperatures on Wednesday and Thursday will be a few
degrees below average near the coast to as much as 10 to 15
degrees below average for the mountains, high desert, and inland
valleys. High temperatures on Wednesday and Thursday will range
from the lower to mid 70s near the coast to the upper 70s to mid
80s for the Inland Empire with the lower to mid 90s for the lower
deserts. Night and morning coastal low clouds and fog will spread
into the far western valleys late each night at times.
&&
.AVIATION...
051000Z...Coast...Low clouds based 800-1200 ft MSL have filled into
most coastal areas and some western valleys. Inland extent will
fluctuate slightly through 15z with clouds up to 15 miles inland at
times. Local vis reductions over higher coastal terrain 2-5 SM.
Clouds clear to beaches 15-17Z and clear over waters shortly,
thereafter. Clouds return to waters and coastal land areas after 06z
Saturday with similar bases, but less inland extent.
Valleys/Mountains/Deserts...Isolated SHRA/TSRA expected over San
Diego County and southern Riverside County mountains again Fri 19-
01Z, with slighter chances (15-20%) for more northerly mtns and
deserts/desert foothills. CB bases of about 10000 feet MSL with TSRA
tops to 35k feet. Gusty, erratic winds, blowing dust with low
visibility, lightning, and lower bases 6000-9000 feet MSL will occur
with any TSRA.
&&
.MARINE...
No hazardous marine conditions are expected through Monday.
&&
.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...17
AVIATION/MARINE...KW

NWS SGX Office Area Forecast Discussion