699
FXUS66 KSGX 171046
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
346 AM PDT Mon Jun 17 2024

.SYNOPSIS...
A little cooler today, around 5 degrees warmer for inland areas
for Tuesday through Thursday, then gradually warmer through the
middle next week with high temperatures warming to 10 to 15
degrees above average for the deserts with high temperatures in
the lower deserts around 115. The marine layer and onshore flow
will keep coastal areas cooler with night and morning coastal low
clouds spreading into portions of the valleys late each night.

&&

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

.SHORT TERM (Today through Wednesday)...
A low pressure system moving inland through the western states
today will strengthen the onshore flow across southern California
and deepen the marine layer. High temperatures today won`t change
much from Sunday near the coast, but be around 5 degrees cooler
for inland areas. There will be gusty southwest to west winds for
the mountains and deserts for late this afternoon through late
this evening with the stronger gusts along the desert slopes of
the mountains around 35 to 45 mph with isolated gusts of 50 to 60
mph in the northern Coachella Valley below the San Gorgonio Pass.

There will be a much drier atmosphere in place for inland areas for
one day on Tuesday with lowest dewpoints for Palm Springs falling
from the mid 40s today to the mid 20s on Tuesday. The lowest
daytime humidity for the lower desert slopes of the mountains into
the deserts will fall to 15 to 25 percent today and 5 to 15
percent on Tuesday.

For Tuesday through Thursday, it will be around 5 degrees warmer
for inland areas. There will be slight day to day differences
with high temperatures for most areas a few to around 5 degrees
below average. The marine layer has deepened to around 2500 feet
with coastal low clouds spreading into the Inland Empire from the
west and south. The marine layer may become slightly shallower for
the middle of the week, but with night and morning coastal low
clouds still spreading inland into portions of the valleys.

The greatest smoke concentrations for southwestern California
through tonight for ongoing fires in southern California are
expected for the mountains and deserts and far inland portions of
the Inland Empire. This does not account for smoke from any new
fires that might start today.

&&

.LONG TERM (Thursday through Sunday)...
For the weekend through early next week, high pressure to the
south will expand northward into the far southwestern states. This
may be followed by additional strengthening of high pressure aloft
across the southwest states for the middle of next week. The
deterministic NBM has Palm Springs reaching 112 on Friday and
Saturday of this week and remaining above 112 through Thursday
the the with a peak of 115 on Wednesday the the. A long-duration
heat wave could develop across the deserts by late this week and
continue through much of next week. The marine layer will continue
keep coastal areas cooler with night and morning coastal low
clouds spreading into portions of the valleys late each night.

&&

.AVIATION...
170830Z...Coast/Valleys...Low clouds with bases 1400-1800 ft MSL and
tops to 2300 ft MSL will continue to spread into portions of the
inland valleys through about 14Z. Vis 3-6 SM where clouds near
terrain. There is a 40-50 percent chance for CIGs at KONT and about
a 30-40 percent chance at KSBD 12Z-15Z. Low clouds clearing inland
15-17Z and near the coast 16-19Z. Low clouds redeveloping along the
San Diego County coast 18/00-03Z and spreading inland and north
overnight with bases around 1500-2000 ft MSL and tops to 2500 ft
MSL.

Mountains/Deserts...Mostly clear with unrestricted vis through this
evening followed by SCT clouds at/above 20,000 ft MSL tonight into
Tue morning. Gusty west winds continue across the mountains and
deserts, strongest this afternoon and evening when gusts 25-40 kt
are expected with isolated gusts 45-50 kt below the San Gorgonio
Pass. MOD-STG up/downdrafts over and east of the mountains through
this evening. Winds slowly weaken tonight into Tue morning.

&&

.MARINE...
Northwest wind gusts up to 20 knots will be possible in the outer
waters this afternoon and early evening. Otherwise, no hazardous
marine conditions are expected through Friday.

&&

.BEACHES...
A combination of a west swell of around 5-6 feet/9-10 seconds and a
south swell of around 2 feet/17 seconds will bring surf of 3-6 feet
along with a high rip current risk through today. Swells and surf
will lower Tuesday. A Beach Hazards Statement remains in effect
through 7 PM this evening.

&&

.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 this evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...SS