669
FXUS66 KSGX 051005
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
305 AM PDT Fri Jul 5 2024

.SYNOPSIS...
Hot weather will continue through the weekend into much of next
week as high pressure remains anchored over the region. The heat
will peak today and Saturday with highs 5 to 15 degrees above
average. Areas near the coast will stay cooler due to the
shallower marine layer, which will continue to bring night and
morning low clouds and patchy fog as well.

&&

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

High pressure continues to dominate the region. The warm air mass
and shallow inversion are contributing to low clouds near the
coast with warm temperatures in higher elevations this morning.
As of 2:30 AM, higher terrain in the San Diego mountains are
sitting in the lower 80s with adjacent valleys in the 60s.

The peak of the heat wave will occur today and Saturday for many
as the near 600 dm area of high pressure dominates the State of
California. Highs are expected to be near 5 degrees above normal
near the coast with temperatures up to 15 degrees above normal for
areas further inland. Per NBM, there are low to moderate chances
of the Inland Empire reaching at least 110 degrees. Chances
increase a bit further into the high desert. Not only will these
locations be hot, but also the higher elevations. Areas below
6,000 feet can expect to see temperatures in the 90s to near 100
degrees. Temperatures will be a degree or two cooler by tomorrow.
We will be on the lookout for temperature records mainly across
the low deserts where highs will reach near 120 degrees.
Confidence on these temperatures lowers some as southerly moisture
at the surface surges in each morning. Depending on how much this
moisture retreats for the afternoon heating of the day will depend
how high the thermometer goes. Heat risk will continue to be high
to extreme for inland areas, so please drink plenty of fluids and
limit time outdoors.

The area of high pressure will slowly move south over Southern
California, weakening slightly near 595 dm. Hot temperatures will
remain for desert areas, with slight cooling west of the mountains
as the marine layer tries to deepen a bit by Sunday and Monday.
Pleasant highs in the 70s at the beaches to 90s and low 100s for
many inland valleys.

The area of high pressure may restrengthen some by the middle of
next week per latest ensemble cluster guidance. This will increase
temperatures yet again, though not as hot as we will see today
and tomorrow. The position of the dome of high pressure is still
more uncertain. If it pushes further east and allows greater
southerly flow to enter our region, we may see a better chance for
monsoon storms to form sometime by the end of next week. NBM POPs
look good for now with a slight signal beginning to show up by
next Thursday and Friday.

&&

.AVIATION...
050945Z...Coast...Low clouds will gradually cover coastal areas this
morning, extending inland locally 15-20 miles by 15Z. Bases will be
900-1200 feet MSL with tops to 1500 feet and reduced VIS 2-5SM in
fog over higher coastal terrain until 16Z. Clearing to the coast
expected 15-17Z. Low clouds will redevelop after 03Z Saturday, with
similar bases/vis.

Otherwise, mostly clear skies with unrestricted VIS through today.

&&

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

&&

.BEACHES...
A long-period south swell will continue elevated surf. The surf will
peak late today through Saturday, before subsiding on Sunday. Sets
of 6-7 feet can be expected on south and southwest-facing beaches,
especially in Orange County. Check the Beach Hazards Statement for
details.

&&

.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 Sunday afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Excessive Heat Warning from 11 AM this morning to 9 PM PDT
     Saturday for Riverside County Mountains-San Bernardino
     County Mountains-San Bernardino and Riverside County
     Valleys-The Inland Empire-San Diego County Mountains-San
     Diego County Valleys.

     Heat Advisory from 11 AM this morning to 9 PM PDT Saturday for
     Orange County Inland Areas-Santa Ana Mountains and
     Foothills.

     Excessive Heat Warning until 9 PM PDT Wednesday for Apple and
     Lucerne Valleys-Coachella Valley-San Diego County Deserts-
     San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...PG