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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

                            
000
FXUS66 KSGX 171115
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
415 AM PDT Wed Jul 17 2019

.SYNOPSIS...
A weak trough of low pressure over the western states will bring
slow cooling today and a little greater cooling for Thursday and
Friday. The marine layer will deepen, with night and morning
coastal low clouds extending into the western valleys this
morning, and portions of the inland valleys for tonight into
Saturday. For this weekend into next week, high pressure will 
strengthen and expand across the southwest states bringing a 
warming trend with the marine layer becoming shallower. An influx 
of monsoonal moisture will begin on Sunday and continue into the 
middle of next week. That will bring increasing humidity to inland
areas, more clouds, and chances for afternoon and early evening 
thunderstorms for the mountains beginning Monday. The increasing 
moisture will keep nights warmer and keep inland high temperatures
from getting quite as hot.

&&

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

.SHORT TERM (Today through Friday)...
A weak trough of low pressure over the western states will
continue the slow cooling today with a little greater cooling for
Thursday and Friday. The marine layer is a little deeper than 24 
hours ago with widespread low clouds across the coastal waters 
extending inland into the western valleys. The marine layer will 
continue to deepen with night and morning low clouds extending 
into portions of the inland valleys for tonight into Thursday and 
Friday. 

&&

.LONG TERM (Saturday through Tuesday)...
high pressure centered over the central and southern plains on
early Saturday, will expand westward and strengthen across the
southwest states for Sunday into the middle of next week. 

A marine layer near 2000 to 2500 feet deep early Saturday, will 
become shallower. Coastal low clouds will extend into portions of 
the inland valleys early Saturday. By the middle of next week, low
clouds will extend inland to only portions of the coastal areas.
Coverage may be patchier as well. depending on the influx of 
monsoonal moisture.

High temperatures will begin to warm on Saturday with warming
continuing on Sunday. For Monday into the middle of next week, the
increasing monsoonal moisture with exert a greater impact on
temperatures with nights generally warmer and inland high
temperatures not quite as hot. 

The initial influx of monsoonal moisture will arrive into
southwest California late Saturday night or early Sunday and
continue into next week. This will bring more clouds and bring
chances for mainly afternoon and early evening showers and
thunderstorms near the mountains. 

&&

.AVIATION... 
170900Z...Coast/Valleys...BKN-0VC005-012 affecting terminals up to 
20 mi inland through 16Z, with clearing toward the coast 16-19Z. 
CIGS not expected to affect KONT/KSBD this morning. Local VIS 3-5 SM 
in BR on coastal mesas and higher coastal terrain through 16Z. 
Patchy and intermittent CIGS likely along immediate coast through 
the day Wed. CIGS redeveloping after 18/00Z with bases 900-1500 ft 
MSL, extending 25 mi inland. 

Mountains/Deserts...CLR with unrestricted VIS through Thursday.

&&

.MARINE... 
No hazardous marine weather is expected through Sunday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...17
AVIATION/MARINE...Rodriguez