Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 250426
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
925 PM PDT TUE MAY 24 2016
Wednesday will be another breezy and cooler-than-average day as a
trough of low pressure moves across the area. A few showers are
possible from the coast to the mountains, perhaps even a
thunderstorm. Although slight warming is forecast Thursday through
Sunday, a persistent trough will keep temperatures slightly below
average through the period.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
The center of a cold core low 200 miles west of Pt Conception this
evening will drift southeast tongiht and then trek across Southern
California Wednesday. Light showers associated with this trough were
detected by radar just west of Pt Conception at 9 pm. As the trough
drifts southeast, showers will be possible later tonight through
tomorrow in increasing PVA and divergent flow aloft. There is also
an outside chance for a thunderstorm from late morning through the
afternoon beneath the -20C 500 mb cold core. Surface CAPE increases
to 200-300 J/kg and LI`s fall below 0 in San Bernardino and
Riverside Counties. Moisture is the limiting factor to our
precipitation potential with the marine layer the primary
contributor. It`s depth this evening was 4600 feet and it will
deepen overnight to around 5000 feet. Precipitation will be widely
scattered and mostly light.
Wednesday will be another cool day with max temps 10-20 degrees
below average in the mtns and deserts, and from 2 to 10 degrees
below average in the coastal and valley zones. Windy again the
mountains and deserts in the afternoon with 15 to 30 mph winds
gusting to 45-50 mph.
Thursday through Sunday: Gradual warming through the period, but
temperatures will remain a little below average due to a persistent
trough over the West. The marine layer will remain intact with night
and morning low clouds spreading inland each night before retreating
back to the coast each day.
250400Z...Coast/Valleys...Areas of BKN low clouds with bases 2500 to
4000 ft and tops to 6000 ft. Bases could lower to 2000 ft or less at
times tonight. Isolated light showers will be possible overnight,
but with minimal impacts. Partial clearing is expected after 17Z Wed
but exact timing is uncertain.
Mountains/Deserts...Coastal slopes below 6000 feet locally obscured,
otherwise mostly clear. West winds with local gusts of 30-40 mph
will produce weak to moderate up/down drafts over and east of the
mountains through tonight.
900 PM...Wind gusts to around 20 knots will be possible Wed
afternoon and evening. Otherwise, no hazardous marine conditions are
expected through Sat.
Skywarn activation will not be needed tonight.