Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 031641
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
941 AM PDT FRI JUL 3 2015

.SYNOPSIS...
LESS HUMID TODAY...WITH AN ISOLATED SHOWER/THUNDERSTORM POSSIBLE
OVER THE SAN BERNARDINO COUNTY MOUNTAINS. DRY...SOUTHWEST FLOW
ALOFT NEXT WEEK WILL CREATE SEASONAL WEATHER...ALONG WITH A
MODERATELY DEEP MARINE LAYER.

&&

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

THE 03/0000 UTC ECMWF AND 03/0600 UTC GFS ARE IN RELATIVELY GOOD
AGREEMENT THROUGH THE LONG-TERM.

AT 9 AM PDT...WATER VAPOR SATELLITE IMAGERY DISPLAYED A BROAD UPPER-
LEVEL HIGH STRETCHING FROM NEVADA TO NORTHERN ARIZONA...AND AN
UPPER-LEVEL LOW AROUND 500 MILES W OF SAN DIEGO. VISIBLE
SATELLITE SHOWED SCATTERED MID AND UPPER-LEVEL CLOUDS OVER
PORTIONS OF THE CWA LEFT OVER FROM CONVECTION OVER CENTRAL MEXICO
YESTERDAY AFTERNOON...AND LOW-LEVEL CLOUDS OVER THE COAST AND
VALLEYS. THE 03/1200 UTC KNKX SOUNDING DISPLAYED AN 8 DEG C
MARINE LAYER INVERSION AND A MUCH DRIER ATMOSPHERE WITH A
CALCULATED PRECIPITABLE WATER OF ONLY 0.94 INCHES. DAYTIME
HEATING...LINGERING MOISTURE AND SLIGHT POSITIVE VORTICITY
ADVECTION WILL CREATE THE POSSIBILITY OF AN ISOLATED SHOWER OR
THUNDERSTORM THIS AFTERNOON OVER THE HIGHEST PEAKS OF THE SAN
BERNARDINO COUNTY MOUNTAINS. ANY STORMS THAT DEVELOP WILL LIKELY
BE SHORT-LIVED AND RELATIVELY LIGHT.

THE AFOREMENTIONED UPPER-LEVEL HIGH WILL MOVE SOUTH THROUGH EARLY
NEXT WEEK...WHILE THE CUT-OFF UPPER-LEVEL LOW TO OUR WEST PUSHES
TOWARDS THE BAY AREA. THIS WILL SHIFT OUR FLOW FROM SOUTHERLY TO
DRY AND SOUTHWESTERLY THIS WEEKEND INTO NEXT WEEK. THE RESULT
WILL BE A MODERATELY DEEP MARINE LAYER WITH NIGHT/MORNING LOW
CLOUDS ALONG THE COAST AND VALLEYS...AFTERNOON BREEZY WESTERLY
WINDS THROUGH MOUNTAIN PASSES AND ALONG DESERT MOUNTAIN
SLOPES...HIGH TEMPERATURES SLIGHTLY BELOW SEASONAL NORMALS AND
PARTLY CLOUDY SKIES EACH AFTERNOON. THIS JUNE-LIKE PATTERN WILL
KEEP THE MARINE LAYER DEPTH AND HIGH TEMPERATURES VARYING ONLY
SLIGHTLY EACH DAY THROUGH THE PERIOD...AND MAY MAKE IT DIFFICULT
TO CLEAR FOR SOME BEACHES IN THE AFTERNOONS.

&&

.AVIATION...
031600Z...COAST/VALLEYS...BKN/OVC STRATUS...WITH BASES 1000-1300 FT
MSL AND TOPS TO 2000 FT MSL WITHIN 15 MILES OF THE COAST WILL
GRADUALLY CLEAR TO THE COAST THROUGH 19Z. SOME HIGHER TERRAIN
OBSCURATIONS WILL OCCUR THROUGH 18Z...THOUGH MOST VIS WILL REMAIN
ABOVE 5 MI BELOW THE CLOUD BASES. THERE COULD BE LOCAL BKN STRATUS
NEAR THE BEACHES THIS AFTERNOON. STRATUS WILL SPREAD 20-25 MI INLAND
TONIGHT...LIKELY REACHING COASTAL AIRPORTS 03Z-05Z WITH SIMILAR
BASES/TOPS TO THIS MORNING. CLEARING COULD BE QUITE SLOW OR EVEN
PARTIAL SATURDAY NEAR THE COAST.

MTNS/DESERTS...A FEW CU/TCU WILL LIKELY DEVELOP OVER THE MOUNTAIN
RIDGES THIS AFTERNOON...MAINLY IN SAN BERNARDINO COUNTY. LOCAL SFC
WINDS FROM THE WEST 15-25 KT GUSTS 35-40 KT WILL OCCUR THROUGH SAN
GORGONIO PASS AND DESERT SLOPES OF THE SAN DIEGO COUNTY MTNS.
OTHERWISE FEW-SCT CLOUDS AOA 15000 FT MSL AND UNRESTRICTED VIS WILL
CONTINUE THROUGH SATURDAY.

&&

.MARINE...
900 AM...NO HAZARDOUS WEATHER IS EXPECTED THROUGH TUESDAY.

&&

.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...JJT
AVIATION/MARINE...MAXWELL



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