Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 051544
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
844 AM PDT Tue Jul 5 2022

.SYNOPSIS...
The upper trough over the Eastern Pacific will continue to weaken
through the weekend while high pressure over the Central US
strengthens and expands westward. This will support a gradual
warming trend through the weekend, with high temperatures Saturday
through Monday topping out up to 5 degrees above average for many
inland areas. Areas near and along the immediate coast will remain
relatively cool during much of this period due to marine layer low
clouds each morning. Cloud coverage will spread into the valleys
each morning through Thursday, after which the marine layer will
become shallower and mostly confined to coastal areas.

&&

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

9 AM Update...Marine layer clouds continue to scatter out over
the coastal valleys this morning. The 12z Miramar sounding
indicates a strong inversion based just below 2000 FT MSL and
extending up to nearly 4900 FT MSL, acting as the culprit for
trapping persistent HZ/FU across the Inland Empire this morning.
Air quality is unhealthy for sensitive groups as a result. The
inversion looks to break this afternoon which will allow for HZ/FU
to mix out, allowing for both air quality and visibility to
improve. The warming trend appears on track for the week ahead, so
no major adjustments to the forecast are planned.

...Previous Discussion Issued at 346 AM PDT...

.SHORT TERM (Today through Thursday)...
High pressure will remain to the east with a trough of low
pressure off the West Coast. The gradual warming trend for the
mountains and deserts will continue into next weekend. The coast
and valleys will warm a few degrees today. The coast will cool
slightly on Wednesday with warming resuming on Thursday and
continuing into next weekend. Areas of night and morning coastal
low clouds and fog will spread into portions of the western
valleys.

&&

.LONG TERM (Friday through Monday)...
The warming trend for the mountains and deserts will continue
through Sunday with not much change on Monday with high
temperatures on Sunday and Monday a few to around 5 degrees above
average. This would result in high temperatures in the lower
deserts around 112 and in the Apple and Lucerne Valleys around
100. For the coast and valleys, high temperatures are expected to
peak on Saturday at a few to around 5 degrees above average, then
cool slightly on Sunday and Monday. Areas of night and morning
coastal low clouds and fog will spread into portions of the
western valleys for early Sunday and Monday mornings. The dry
weather will continue through next weekend with NBM daily measurable
precipitation chances remaining below 10 percent through next
week.

&&

.AVIATION...
051530Z...Coast/Valleys...BKN-OVC015-025 at the coast becoming
SCT020-025 btwn 17-19Z. Vis restrictions 1-4 miles at KONT/KSBD in
smoke and haze from July 4th fireworks clearing btwn 20-22Z.

Low clouds returning back to the coastal areas by 06/02Z, then
moving into the inland valleys overnight with bases 2000 ft MSL and
tops 2500 ft MSL.

Mountains/Deserts...Mostly clear with unrestricted vis through Wed.
W-NW winds 25-35 kt over/east of mtns and deserts 06/00-07Z with
areas of moderate up/downdrafts east of the mountains.

&&

.MARINE...
Northwest winds with gusts to 25 knots near San Clemente Island this
afternoon. A Small Craft Advisory has been issued for the outer
coastal waters from 2 PM today through midnight tonight. Winds
weaken tonight, then strengthen again Wednesday afternoon and
evening with gusts to around 20 kt. No hazardous marine weather
Thursday through Saturday.


&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory from 2 PM this afternoon to midnight PDT
     tonight for Waters from San Mateo point to the Mexican
     Border Extending 30 to 60 nm out including San Clemente
     Island.

&&

$$

PUBLIC...Adams
AVIATION/MARINE...Moede


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