306
FXUS66 KSGX 181632
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
932 AM PDT Wed Sep 18 2024

.SYNOPSIS...
A low pressure system from the northwest will bring chances for
light precipitation for Thursday into Friday with more clouds from
the coastal waters to the mountains. Low pressure will weaken with
dry and much warmer weather for the weekend into early next week
with high temperatures warming to a few degrees above average on
Sunday and around 5 degrees above average on Monday.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
No significant changes to the forecast this morning as the
widespread marine layer and generally stable conditions have
helped keep the previous forecast on track.

previous discussion... 340 AM Wednesday September 18th 2024

The marine layer has decreased in depth to around 3500 feet. The
inversion strength is still quite weak with mostly patchy coverage
or less of coastal low clouds. High temperatures for today will
be a few to around 5 degrees warmer than Tuesday, but still 10 to
15 degrees below average for the mountains and inland valleys.

The center of a closed low pressure system from the northwest will
move to near Point Conception on Thursday, then move slowly across
southern California on Thursday night and Friday and into Arizona
on Friday night. High temperatures will be a few degrees cooler on
Thursday and only slightly warmer for Friday.

This low pressure system will bring chances for light showers at
times for Thursday into Friday. Amounts are expected to be light
with any precipitation falling for only a limited amount of that
time for most areas. Chances for measurable precipitation is
generally around 25 to 35 percent for the coast to the mountains
with chances for one-quarter inch or more of rainfall around 5 to
10 percent.

&&

.LONG TERM (Saturday through Tuesday)...
The center of low pressure over southern California on Friday will
move into Colorado on Saturday with lingering low pressure across
southern California on Sunday. There is greater spread across
California for Monday through Wednesday of next week ranging from
weaker low pressure to weaker high pressure.

Dry and much warmer weather is expected for the weekend into early
next week, but with increasing spread in the high temperature
forecasts, especially beyond Monday. With the warming, high
temperatures will go from a few to around 5 degrees below average
on Saturday to a few degrees above average on Sunday and around 5
degrees above average on Monday and Tuesday. High temperatures for
the inland valleys will go from mostly in the 80s on Saturday to
the upper 80s to upper 90s on Sunday and the 90s to around 100 for
Monday followed by a few degrees of cooling for Tuesday.


&&

.AVIATION...
181500Z...Coast to mountain ridges...Patchy low clouds will continue
this morning, mostly in San Diego County, with bases around 2500-
3200 feet MSL and tops to 3300-3500 feet. Local terrain obscurations
within that layer. Low cloud decks will break up to SCT 16-18Z. More
widespread low clouds will develop along the coast after 00Z and
gradually fill in the entire coastal basin overnight into Thursday.
Bases will be around 1800-2500 feet MSL starting out but will
gradually rise overnight into early Thursday morning to around 2100-
2800 ft MSL. Clouds partially scattering 17-19Z, but may linger in
southern San Diego Co.

Mountain ridges to Deserts... Mostly clear today and tonight.

&&

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

&&

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

&&

$$

PUBLIC...Suk
AVIATION/MARINE...CSP