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Area forecast discussion 
National Weather Service San Diego California
930 am PDT Mon Oct 24 2016

the widespread thunderstorms over Orange, western Riverside and
southwestern San Bernardino counties have decreased in intensity,
and just scattered showers and isolated thunderstorms will continue
through this afternoon under the trough of low pressure. The low
pressure system will move east tonight, and fair weather will return
and continue through Thursday with a gradual warming trend. Some low
clouds and fog will occur at times near the coast Tuesday through
Thursday. There is a chance of rain Friday as another trough of low
pressure develops, along with cooler weather.


Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino

Numerous thunderstorms occurred earlier this morning, especially in
Orange, western Riverside and SW San Bernardino counties. Maximum
unstable CAPES exceeded 1000 j/kg in the 850-700 mb layer which was
quite moist, contributing to total precipitable water amounts of
around 1.2 inches, though outside of areas receiving rain, the layer
below 850 mb was dry. 120-knot jet was to our southwest, with good
diffluence over our area. Over 1000 lightning strikes have occurred
over our forecast area in the past 24 hours, and some power poles
have been damaged due to lightning strikes, especially San
Bernardino County. Most of the precip and lightning was decreasing
at mid-morning, with scattered showers/isolated thunderstorms mainly
north of San Diego County. With an upper low about 200 miles, we
could have some more precip through this afternoon, though no
lightning strikes are currently to our southwest. There does continue
to be good mu cape aloft though. After the trough axis passes trough
around 03z tonight, precip should be gone. Today should be our
coolest day with 70s west of the mountains and 80s in the lower
deserts, but ridging over the western US should bring a gradual
warming trend Tue-Thu with 80s in the valleys Wed/Thu and 90s in the
lower deserts, though coastal areas will be only in the lower to mid
70s due to onshore flow which should bring some stratus/fog,
especially Tue and Wed nights.

Mean troughing continues off the West Coast for the next week, and a
strong deep trough will develop the second half of next week. The
effects of the trough will be greatest to our northwest where
moisture will be more abundant, and dynamics will be better. When a
shortwave moves through California on the east side of the trough
Friday, we could have some precip in our forecast area. The trough
could send more waves through California over the weekend through
early next week, but we will be at the southeast fringe of the moisture, so
precip amounts will not be great, most likely under 1/2 inch.


241530z...scattered showers and a chance of thunderstorms will
continue today. Cloud bases will be as low as 5000 feet msl in
showers, but mostly in variable layers above 8000 feet. Vis locally
reduced 3-5 sm in heavier showers. Precip chances decrease through
the day today, ending after 00z, with skies gradually thinning of
clouds this evening. Patchy low clouds could return to the coast
overnight tonight, but confidence is low to moderate and will depend
on if/when the higher clouds dissipate. Better stratus return is
expected for Tuesday night.


slight chance of thunderstorms today, but mainly this morning. The
biggest threat would be cloud-to-water lightning. The marine weather
statement highlights this threat through midday, with chances
continuing to decrease this afternoon. Otherwise, no hazardous
marine weather is expected through Friday.


slight chance of thunderstorms, mainly this morning. Isolated
lightning strikes on the beaches are possible. The chance for
thunderstorms will decrease through the day today. A beach hazards
statement will be renewed be issued if/when lightning strikes are


Skywarn activation is not requested at this time. However weather
spotters are encouraged to report significant weather conditions.


Sgx watches/warnings/advisories...



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