San Diego Weather at Mission Trails, CA

000
FXUS66 KSGX 200925
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
225 AM PDT Thu Sep 20 2018

.SYNOPSIS...
Low clouds near the coast and in the lower desert this morning
will give way to mostly sunny skies, except partly cloudy in the
mountains. Otherwise, fair and slightly warmer weather will
continue with areas of coastal low clouds nights and mornings.

&&

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

We`re watching a tale of two marine layers this morning with
areas of low clouds forming along the coast and also in the lower
desert. An impressive gulf surge overnight spread humid air and
some clouds into the low desert sloshing up against the mountains.
Meanwhile, the coastal clouds are gradually developing and
expanding in coverage. Mostly sunny skies will prevail after most
of these clouds evaporate later this morning, but the humid surge
from the southeast will create cumulus clouds in the mountains. It
still appears that any chance of rain is too low to mention in
the forecast. A coastal eddy appears to develop timidly today, but
strengthen tonight into Friday. That will give us a similar
coastal cloud pattern again. The desert moisture decreases a bit,
but sticks around Friday for partly cloudy skies in the mountains
and desert. A slight strengthening of high pressure aloft will
bring a few degrees of warming this weekend, and the marine layer
and coastal cloud coverage will diminish a little. A trough of low
pressure moves through the West Monday and Tuesday for slightly
cooler weather again. And it looks as though that trough could set
us up for some weak offshore flow Tuesday and beyond. A decent
high pressure ridge develops over the West Coast at the same time,
especially over WA, OR and NorCal. They look to get a serious
warming trend with decent offshore flow for them. Here in SoCal it
looks like we`ll get a more tepid warming trend with light
offshore flow. That might chase away the coastal clouds and should
boost temperatures several degrees above seasonal averages.

&&

.AVIATION...
200900Z...Coast/Valleys...Stratus with bases 1000-1500 ft MSL will
continue to fill in along the coast and spread 10-15 mi inland this
morning. Local vis 3-5 SM in BR/HZ possible in the far western
valleys of San Diego County. Stratus/vis restrictions clearing 15-
17Z. Stratus redeveloping along the coast after 21/02Z with bases
1200-1700 ft MSL and moving 15-20 mi inland overnight. Otherwise a
few clouds AOA 6000 ft MSL through Friday morning.

Mountains/Deserts...Patchy low clouds will continue over the lower
deserts and adjacent desert mountain slopes through about 14Z. Bases
will be near 2500 ft MSL with local mountain obscurations. Scattered
cumulus forming over the mountain crests this afternoon with a small
chance of showers through the early evening, mainly over Riverside
and San Diego Counties. Otherwise a few clouds AOA 6000 ft MSL
through Friday 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...MM
AVIATION/MARINE...SS