Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 310434
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
934 PM PDT SAT JUL 30 2016
Monsoonal moisture will continue to result in a few afternoon and
evening thunderstorms in the mountains and deserts with the
potential for flash flooding on Sunday. Chances for afternoon
thunderstorms near the mountains will continue into the middle of
next week. A shallow marine layer will keep low clouds and fog at
the coast during the nights and mornings. A gradual cooling trend
for inland areas will continue into the latter half of next week
with decreasing monsoonal moisture after Thursday.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
Dust was a big weather story today. Severe thunderstorms which
erupted over Arizona last evening, produced outflow winds which
spread dust across the Coachella Valley and into portions of the
Inland Empire with suspended dust even to portions of the coast.
This lead to hazardous air quality over a large portion of SoCal.
A few thunderstorms developed over mainly the San Bernardino
mountains and the high desert. Max measured rainfall today was
0.55" recorded 1 mile NW of Idyllwild-Pine Cove. No high winds
The San Diego sounding this evening recorded PW at a high 1.88
inches. So the monsoonal moisture is present here in SoCal. Sunday
afternoon we expect similar tstorm activity in the mountains and
possibly into the deserts as well.
From previous discussion...
Through Thursday...The overall pattern is expected to change only
slowly as we go into next week. As a result, we can expect coastal
low clouds and fog to persist during the nights and mornings, and
monsoonal moisture to continue the chances for afternoon/evening
showers/tstms. However, a trough of low pressure deepening over
the west coast will weaken the upper high over the Desert
Southwest and bring a gradual lowering of temps and an increase in
coastal marine layer low cloud and fog during the nights and
Friday and Saturday...Expect a noticeable decrease in the
monsoonal moisture and an increase in the the marine layer as
SOCAL come more under the influence of the low pressure trough
over the west coast.
310400Z...Coast and Valleys...Patchy marine stratus will extend
again from the coastal waters inland up to 10 miles late tonight
with bases 1000-1300 FT MSL and tops below 2K FT MSL through around
16-17z. Brief vis restrictions 1-3SM in BR where stratus intersects
higher coastal terrain. Otherwise, SCT clouds AOA 15000 ft MSL.
Mountains...P6SM SCT-BKN150, Isold/Sct thunderstorms aft 18z Sunday
with strong UDDFS and LLWS, strong wind gusts possible to 40 knots,
Deserts...P6SM SCT150, with possible thunderstorm activity, mainly
after 18z Sunday, with strong UDDFS and LLWS, gusts to 40 knots
possible, and +RA in the high desert.
No hazardous marine weather is expected through Wednesday.
A south swell from 200 degrees at 2-3 Ft with a period of 18
seconds, will build into the coastal waters on Sunday afternoon.
This will produce elevated surf, strong longshore currents, and
strong rip currents, resulting in dangerous swimming conditions. The
surf/swell is forecast to peak Sunday evening around the time of
evening high tides which may result in minor tidal overflow at
susceptible beaches. A Beach Hazards Statement has been issued for
Sunday morning through Monday evening. Surf, swell, and tides will
slowly lower through the rest of the week.
Skywarn activation is not requested. However weather spotters are encouraged
to report significant weather conditions.
CA...Beach Hazards Statement from 8 AM PDT Sunday through Monday
evening for Orange County Coastal Areas-San Diego County