158
FXUS66 KSGX 140330
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
830 PM PDT Tue Aug 13 2024

.SYNOPSIS...
Fair and seasonal weather will continue through the weekend.
Areas of coastal low clouds will continue nights and mornings,
extending into western valleys. Temperatures will remain around
normal, followed by a warming trend next week.

&&

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

.Evening Update...
Ribbons of low clouds are beginning to form over the sea and near
some of our beaches this evening. Latest NBM/HRRR model output
depicts increasing coverage of these clouds, mainly after
midnight. Dry conditions will prevail through at least Friday as
drier air has come into the picture. Precipitable water levels
have gone down from 1.30 inches to 0.80 inches, when comparing
yesterday and today`s upper air soundings from Miramar in San
Diego.

There will be minimal changes in temperatures from day to
day through the weekend as we stay sandwiched in between a trough
to the north and west and a ridge to the south and east. The ridge
looks to slowly nudge back westward by the weekend, which may
prompt more monsoonal activity. Some ensemble models show hints of
this occurring. Otherwise, no forecast changes this evening.

.Previous Discussion (134 PM Tuesday)...

Coastal low clouds and fog have fled, but will eventually have
very similar coverage tonight into Wednesday as they did this
morning. But coastal low clouds should not be as prevalent or
uniform for early Thursday. What you see now is what you get:
lots of sunshine. Gusty westerly winds will blow through parts of
the mountains and deserts through tonight. Top gusts in the
windiest places, the usual spots through passes into adjacent
deserts, will exceed 40 mph. A weaker version of these westerly
winds will manifest itself late Wednesday. Temperatures will be
within a few degrees of normal through the rest of the week, with
only minor variations day to day. Very slightly warmer Thursday,
slightly cooler Friday and Saturday. A weak trough of low pressure
over the Pacific Northwest will continue to press against a
stubborn high pressure ridge over Texas for what looks like
forever.

This weekend, a trickle of monsoonal moisture begins to
flow into SoCal. For several days, the moisture is insufficient
for thunderstorms through at least the weekend, but eventually
there might be enough moisture and instability for storms in the
mountains and deserts by Tuesday or Wednesday. Early next week,
the ridge imposes itself just a little more to bring a modest
warming trend.

&&

.AVIATION...
140330Z...Coast/Valleys...Low clouds with bases
700-1000 feet MSL and tops to 1200 feet beginning to gather at the
coast this hour. Low clouds will increase in coverage and spread
up to 10 miles inland by 14Z. 40-60 percent chance of CIGs at KSAN
and KCRQ at 09Z becoming 60-80 percent by 14Z. About a 30 percent
chance for CIGs at KSNA at 09Z becoming about 75 percent by 14Z.
Local VIS 3-5 miles on higher coastal terrain. Expect clearing to
the beaches 15Z-16Z.

Mountains/Deserts...Mostly clear with unrestricted VIS through
Wednesday morning.

&&

.MARINE...
No hazardous marine conditions are 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...APR/MM
AVIATION/MARINE...PG