Jacumba, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

984
FXUS66 KSGX 160426
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
926 PM PDT Sun Mar 15 2026

.SYNOPSIS...
High pressure off the coast will continue to pass over the region
and strengthen through the week, bringing a long-duration and early
season heat wave. Patchy low clouds and fog will occur once again
near the coast on Monday morning before mostly clear skies take hold
thereafter. This heat event will encompass temperatures up to 30
degrees above normal for this time of year, leading to moderate to
high heat risk and record breaking temperatures. The area of high
pressure will begin to weaken by next weekend, allowing for a
gradual cooling trend.

&&

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

...AVIATION SECTION UPDATED...

Update: With weak offshore winds returning to the region, it is
going to help to suppress marine layer development along to coast
tonight, with mostly clear skies prevailing. The ridge will continue
to strengthen throughout the week, with the ridge peaking out in
intensity by Thursday into Friday. Not only are temperatures
exceptionally warm, given the time of year, but the duration of
prolonged heat for widespread locations is what is making this an
unprecedented heat wave, especially for this time of year. By
Thursday, it is possible that there will be a few locations possibly
breaking monthly records, and then again on Friday as temperatures
will be at their hottest. There could even be a few locations
flirting with all-time records, with projected temperatures reaching
into the mid to upper 100s within the IE for the later part of the
work week. We will finally begin to see relief from this immense
heat beginning the following weekend; cooling from west to east.
This will occur as the ridge begins to finally weaken with more
troughing influencing the region. Be sure to stay alert to any
updates to our Heat Watches and Advisories at weather.gov/sgx/

Previous discussion submitted at 1251 PM:

Marine layer clouds have cleared out from this morning as the marine
layer reached its max depth of the week near 1500-1800 feet. An area
of high pressure off the coast will continue to strengthen,
suppressing the marine layer into tonight and Monday morning. This
will leave the chance for low clouds and fog to return closer to the
immediate coast by Monday morning. The area of high pressure will
strengthen into the upcoming week, with mostly clear skies expected
across SoCal Tuesday onward.

High temperatures today will be fairly similar to yesterday across
the region with the greatest warming of 3-5 degrees expected across
the Inland Empire and Orange County. Upper level winds will be
offshore on Monday and Tuesday as the high strengthens, which will
contribute to a warming trend and long-duration heat wave across the
region. The high will be centered over our area by Tuesday and
Wednesday, becoming a very strong and hot air mass as models depict
a ~594 dm high over the region. This will bring temperatures near 20
to 30 degrees above normal by this time period. Tuesday will be the
first day of triple digit heat for some parts of the Inland Empire
and lower deserts. Temperatures increase slightly on Wednesday, most
notably over the mountains and deserts by another 3-5 degrees. 80s
will be common across the mountains of RIV/SD Counties with 70s and
lower 80s in the SBD mountains. The mountains will not be escaping
the heat this week, so please limit outdoor recreation each
afternoon in these areas.

Models continue to show the timing of the high peaking in strength on
Thursday and Friday. This will bring the hottest temperatures of the
week across the area as models show an unusual summer-like 595-597
dm high over our region as we enter the first days of spring. Our
confidence is moderate on the exact strength of the high, which will
dictate exactly how hot we get later this week. The average high in
Julian in the SD County mts this time of year is 57 degrees but has
around a 60-75% chance of seeing highs reach 90 by Thursday and
especially Friday. Not only record temperatures for the month of
March are expected to break, but also even for April. The record
highs for the month of April at Indio and Thermal are 110 for both
sites, where NBM indicates a ~70% chance of breaking this record.
Triple digit heat has around a 50-50 chance of occurring across the
inland San Diego valleys (Alpine, El Cajon, Poway, etc.) and
northern Orange County (Lake Forest, Anaheim, etc.). Temperatures
will likely surpass the 100 degree mark across the Inland Empire on
Thursday and Friday, with areas around San Bernardino and Riverside
seeing a 50-70% chance of temperatures reaching 105 degrees. March
record highs for Big Bear (80 degrees) and Idyllwild (82 degrees)
will likely be broken during this time period as well.

With moderate to high heat risk in the forecast, please check on
family, friends, and neighbors this coming week! Make sure you have
plenty of water and fans to cool off if there is no cooling system
or cooling centers available near you. Outdoor activities should be
limited as the duration of this early season heat wave will lead to
increased risk of heat illness.

Models show fair agreement on the ridge slowly breaking down by next
weekend. This will help spread onshore flow and subtle cooling first
from the coast to the mountains on Saturday, then all areas by next
Sunday. Models become more varied by early next week, but the warmer
than average and dry weather pattern looks to continue as we head
toward the end of March.


&&

.AVIATION...
160500Z...Coasts/Western Valleys...Patchy low clouds 300-800ft MSL
reform and move in coastal areas after 08Z, moving 10-15 miles
inland overnight. Vis restrictions 3-5SM will be possible mainly
across coastal mesas and inland valleys. Clouds will be more
patchwork than last night, leading to low to mod confidence in
initial timing of cigs, and intermittent scatter out overnight is
likely. Low clouds clear in most areas 14-16Z, followed by
widespread VFR.

Inland Valleys/Mountains/Deserts... Another period of N/NE offshore
winds over coastal mountain slopes, through mountain passes, and
locally stretching into eastern valleys areas 18Z Mon to 02Z Tue.
Winds gusting 20-25 kts.

&&

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

&&

.BEACHES...
A long period (17-19 second) south-southwesterly swell (190-200
degrees) builds to 2-4 feet Monday afternoon into Tuesday. This will
lead to breaking waves of 4-6 feet, with sets up to 7 feet possible
on south-facing beaches. This swell is expected to persist into
Wednesday, waning Wednesday night.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Wednesday evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Heat Advisory from 10 AM Monday to 8 PM PDT Friday for Orange
     County Coastal Areas-Orange County Inland Areas-San
     Bernardino and Riverside County Valleys-The Inland Empire-
     San Diego County Coastal Areas-San Diego County Valleys-
     Santa Ana Mountains and Foothills.

     Extreme Heat Watch from Thursday morning through Friday evening
     for Coachella Valley-Riverside County Mountains-San
     Bernardino County Mountains-San Diego County Deserts-San
     Diego County Mountains-San Gorgonio Pass near Banning.

PZ...None.

&&

$$

PUBLIC...Stewey
AVIATION/MARINE/BEACHES...CSP