Severe Thunderstorm Warning 10, NWS San Diego, CA

Area Forecast Discussion
National Weather Service San Diego CA
145 PM PDT Mon Jul 15 2024

.SYNOPSIS...
Monsoonal moisture will bring several thunderstorms with locally
heavy rain over the mountains and deserts this afternoon, followed
by isolated showers and thunderstorms over the mountains on
Tuesday afternoon. After some drier days, the monsoon moisture and
chances of thunderstorms return toward the end of the week.
Temperatures will be near normal, climbing to above seasonal
normals the second half of the week. Coastal low clouds will
continue nights and mornings.

&&

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

Cumulus clouds over the mountains late morning grew into quite a
few cumulonimbus clouds, also known as thunderstorms, this
afternoon. Thunderstorms will continue over the mountains, and
will also drift into the deserts, especially the high desert,
mainly east of I-15. A thunderstorm or two could present some
trouble in the form of isolated flash flooding or severe weather
(strong winds and/or hail). The best model guidance shows a pretty
clean finish on the chances of thunderstorms before sunset.
Monsoon moisture continues to decrease through Wednesday, right
now just enough for a very slight chance of thunderstorms in the
mountains Tuesday afternoon. With the monster high pressure ridge
over the West taking a temporary break over SoCal, temperatures
will mellow out from the extremes of the last two weeks; max temps
rise to around normal today and Tuesday. The ridge begins to
strengthen again Wednesday to start yet another warming trend, and
max temps rise several degrees above normal in the mountains and
deserts. The trend continues so that the entire region goes a
little above normal by Thursday. With the ridge axis to our north,
that will re-open the monsoon door allowing more mid level
moisture to come into SoCal from Mexico. Models and ensembles
differ quite a bit on the extent of moisture, and the implied
chances of thunderstorms, but it appears we'll have some
increasing chance toward the end of the week. Right now we have
small chances in the mountains starting Friday afternoon, with
higher chances over the weekend expanding into the deserts. We
haven't forgotten you, coastal low clouds. The cloud coverage will
remain very similar each night and morning. Rinse and repeat. If
any minor trend can be detected, it would be slightly lesser
coverage in time and space for the latter half of the week.

&&

.AVIATION...
152010Z...Coast/Valleys...BKN-OVC clouds with bases 500-1200 ft MSL
locally linger at beaches this afternoon. Low clouds are expected to
redevelop and move inland 02-08Z Tue, with bases 700-1200 ft MSL,
and are expected to reach 15-20 miles inland by 14Z. Confidence in
arrival time at KSAN of 03Z is moderate.

Mountains/Deserts...TSRA expected through 02Z Tue in the mountains
with BKN100. Heavy rainfall, erratic winds, and strong up/downdrafts
expected where storms develop. There is a 20-25 percent chance of
RA/TSRA in the deserts through 00Z Tue, with the potential for
strong outflow gusts and lightning from nearby storms to impact KPSP
and KTRM.

&&

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

&&

.BEACHES...
Long period SSW swell (200-210 degrees) of 3ft/16-18 sec will bring
surf of 4-6 ft to Orange and northern San Diego County beaches. Sets
to 7 ft are possible on Tuesday and Wednesday. The highest surf will
occur on southwest facing beaches. There is a high risk of dangerous
rip currents. A Beach Hazard Statement is in effect for Tuesday
morning through Thursday evening. The surf will gradually decrease
Thursday through the weekend as the period decreases to 14-15 sec
and the swell height falls to 2 ft.

&&

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

&&

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

PZ...None.

&&

PUBLIC...MM
AVIATION/MARINE/BEACHES...Small