Severe Thunderstorm Warning 15, NWS San Diego, CA

Area Forecast Discussion
National Weather Service San Diego CA
137 PM PDT Thu Sep 26 2019

.SYNOPSIS...
Scattered showers and isolated thunderstorms are expected to
continue through this evening, focusing over the mountains and
deserts. The precipitation will move east tonight with dry
weather through Friday, although clouds will linger into Friday
morning. Cooler and cloudy with a chance of light precipitation
from the coast to the coastal mountain slopes Friday night through
Saturday, along with strong and gusty westerly winds in the
mountains and adjacent desert areas. Dry and cool for early next
week then a little warmer for the middle of next week.

&&

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

This afternoon, a few light showers continue to move southwest
across SoCal but precip amounts remain small. Scattered tstms have
developed over the higher elevations of eastern Riverside County
and they could drift westward into the Coachella valley. Heavy
showers and/or tstms could still develop over our local mtns, but
the likelihood will decrease through this evening. Widespread low
clouds persist west of the mtns and will likely continue through
tonight.

Tonight, the closed low will move eastward taking the precip with
it and becoming an open wave over AZ by late tonight. This trough
continues to move east on Fri and is replaced by another
low/trough moving southeast across the Pacific Northwest. This new
system becomes the dominant feature over the western U.S. as it
deepens through Sunday.

Friday will be a transition day of sorts, characterized by mostly
fair weather, except for marine layer clouds west of the
mountains in the morning.

As the low/trough deepens over the west coast, it will bring much
cooler weather for Saturday and Sunday, with gusty west winds in
the mtns and deserts and a chance for light precip from the coast
to the foothills. Wind gusts of up to 55 mph will be possible Sat
afternoon/evening.

For the first half of next week, the trough weakens allowing
temperatures to recover somewhat although daytime temps remain a
little below seasonal averages. Expect mostly fair weather except
for marine layer low clouds and fog during the nights and
mornings.

&&

.AVIATION...
261950Z...Stratus will prevail for most of the coast and valleys
through the afternoon with varying bases 3000-4500 FT MSL. Areas of
SHRA and TSRA currently east of the Coachella Valley may drift to
sites KPSP/KTRM this afternoon. MOD confidence for chance of storms
also in the mountains and along the coastal slopes as well through
the afternoon. Gusty surface winds, strong up/downdrafts, and
reduced VIS in rain are possible near storms. Bases lowering to
around 1500 ft MSL after 02Z this evening for the coasts and
valleys west of the mountains. Moderate confidence in some lower VIS
of 2-4 SM BR where low clouds near higher terrain.

&&

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

&&

.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...PG
AVIATION/MARINE...APR