410
FXUS66 KSGX 041612
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
912 AM PDT Tue Jun 4 2024

.SYNOPSIS...
High pressure aloft will continue the inland warming trend, with
heat peaking on Thursday and Friday. High temperatures for the
mountains and deserts will generally be 8 to 12 degrees above
average, exceeding 105 in portions of the Apple and Lucerne
Valleys and 110 in the lower deserts. The marine layer will keep
coastal areas cooler with night and morning coastal low clouds,
but not spreading as far into the valleys for Thursday and
Friday. Then gradually cooler for Saturday through Monday.

&&

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

High pressure aloft over the western US will continue the warming
trend through Thursday for most inland areas. Highs along and
near the coast today will be near-to-slightly-above seasonal
normals, while inland areas range generally from 5 to 10 degrees
above normal. The warmest days for areas west of the mountains
generally look to be Wednesday and Thursday, while the lower
deserts see peak heat occur on Thursday and Friday. Widespread
highs between 100 and 105 for the High Deserts and highs of 108 to
113 for the lower deserts will occur during their respective
hottest days. The Inland Empire will see highs routinely ranging
from the middle 80s to middle 90s starting today as well. While
these temperatures are warmer than seasonal averages for early
June, very few, if any daily temperature records look to be
challenged. The coasts will remain relatively cool through this
week owing to marine layer clouds each morning. High pressure
aloft will cause the marine layer to become more and more shallow,
with morning low clouds only covering portions of the inland
valleys by this weekend.

The high pressure aloft then looks to weaken and give way to upper
level troughing later this weekend and early next week. Upper
troughing does look to draw in the remnants of an upper low
over/near the southern Baja California coast, but overall impacts
to sensible weather look to be minor, perhaps some extra high
clouds owing to a lack of deep-layer moisture. The ultimate
impacts look to be a gradual cooling trend and a re-deepening of
the marine layer. Highs will still be rather hot in the deserts,
generally 105 to 110 in the lower deserts and the middle to upper
90s for the high deserts. Marine layer clouds will gradually
become more expansive again during this time. And begin to spread
back in and cover all of the coastal basin again by early next
week.

&&

.AVIATION...
041545Z...Coast/Valleys...Low clouds with bases 1300-1500 feet MSL
and tops to 2500 feet cover the coastal areas and much of the inland
valley at this hour. Clearing is begging at the inland edges of the
cloud layer. Expect clearing to the coast around 20Z but SCT-BKN
conditions will likely persist into the afternoon at the immediate
coast. Low clouds will move ashore after 00Z and spread locally into
valleys through 14Z Wednesday. Bases around 1000-1500 feet MSL,
higher terrain obscured and inland VIS reduced.

Otherwise...Decreasing high clouds today and mostly clear tonight
with unrestricted VIS.

&&

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

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning from 10 AM Wednesday to 9 PM PDT Friday
     for Apple and Lucerne Valleys-Coachella Valley-San Diego
     County Deserts-San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...Adams
AVIATION/MARINE...PG