Special Weather Statement, NWS San Diego, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
850 PM PDT WED OCT 14 2015

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL DRIFT ACROSS SOUTHERN CALIFORNIA
THROUGH FRIDAY ACCOMPANIED BY AREAS OF CLOUDS...COOLER WEATHER...
AND A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY IN THE MOUNTAINS
AND DESERTS.THE COOLER WEATHER WILL PERSIST THROUGH THE WEEKEND...
FOLLOWED BY OFFSHORE FLOW AND WARMER WEATHER AGAIN EARLY NEXT WEEK.

&&

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

EVEN THOUGH CUMULUS WERE BUILDING OVER THE MOUNTAINS TODAY...ONLY
ONE GOOD STORM MANAGED TO DEVELOP IN THE FAR SOUTHERN SAN DIEGO
COUNTY DESERT AROUND SUNSET. AT 8 PM PDT...NO RADAR ECHOES REMAINED.
THE 00Z MIRAMAR SOUNDING WAS QUITE IMPRESSIVE WITH AN MU CAPE VALUE
OF 2691 J/K...AND A PW AROUND 1.35 INCH. WINDS WERE LIGHT WESTERLY
BELOW 3K FT...BECOMING SOUTHERLY 35-50 KT ABOVE. A WEAK 3.5 DEGREE
C INVERSION WAS BASED NEAR 1500 FT.

SATELLITE IMAGERY SHOWED LOW CLOUDS WERE FORMING ALONG THE
COAST...WHILE HIGHER CLOUDS WERE PIVOTING OVER THE CA BIGHT
FROM THE LOW PRESSURE AREA OFFSHORE. WATER VAPOR IMAGERY THIS
EVENING HAD THE CENTER OF THE UPPER LOW ABOUT 300 MILES NW OF SAN
DIEGO...TRACKING SLOWLY NE. HEAVIER CONVECTION SOUTH OF THE CENTER
EARLIER IN THE DAY HAD DISSIPATED...BUT IR IMAGERY STILL SHOWED
PATCHES OF ENHANCEMENT OFFSHORE.

THE 00Z NAM12 APPEARS TO HAVE INITIALIZED THE CENTER OF THE UPPER
LOW WELL. THE LATEST MODEL SOLUTIONS ARE VERY CLOSE WITH OPENING THE
CENTER AND TRACKING IT EAST ACROSS THE SOUTHERN THIRD OF THE STATE.
DRIER AIR IS BEING DRAWN NE AHEAD OF THE LOW AND WILL OVERSPREAD THE
COASTAL AREAS ON THU. THIS WILL FAVOR THE MTS/DESERTS WITH THE BEST
CHANCE OF SHWRS/TSTMS AS THE LOW MOVES INLAND AND WEAKENS. POPS WERE
LOWERED MOST AREAS AND ELIMINATED ALONG THE COAST AFTER THU MORNING.
SOME FOG COULD DEVELOP AGAIN OVERNIGHT WEST OF THE MTS DUE TO THE
HIGH SFC DEWPOINTS AND VARIABLE CLOUD COVER.

A STRONGER WAVE FROM THE NW WILL ARRIVE OVER THE WEEKEND. THE GLOBAL
MODEL SOLUTIONS ARE COMING INTO BETTER AGREEMENT THAT THIS FEATURE
WILL TRACK JUST NE OF THE CWA. THIS SHOULD LIMIT PRECIP CHANCES
HERE...BUT WILL BRING IN SOME DRIER AND COOLER AIR BRIEFLY. BY
TUE...HIGH PRESSURE IS REBUILDING ACROSS THE GREAT BASIN AND MAY
SWING OUR WINDS OFFSHORE...RESULTING IN A RAPID WARM-UP INTO
THE MIDDLE OF NEXT WEEK.

&&

.HYDROLOGY...
STILL LOOKING FOR HIT AND MISS SHOWERS AND THUNDERSTORMS...MAINLY
OVER THE NORTHERN MOUNTAINS AND HIGH DESERTS INTO FRI AFTERNOON.
BRIEF...HEAVY RAIN WILL BE POSSIBLE FROM THE STRONGER THUNDERSTORMS.
OTHERWISE...LIGHT TO MODERATE AMOUNTS OF RAIN ARE EXPECTED. THE
THREAT OF ANY SMALL STREAM FLOODING/FLASH FLOODING WILL BE LIMITED.

A SLIGHT CHANCE OF SHOWERS REMAINS IN THE FORECAST WEST OF THE
MOUNTAINS THROUGH THU MORNING. QPF HAS BEEN DECREASED. OTHER THAN
LOCAL AMOUNTS...GENERALLY LESS THAN ONE INCH IS NOW FORECAST OVER
THE SAN BERNARDINO COUNTY MOUNTAINS.

&&

.AVIATION...
150345Z...AREAS OF BKN STRATUS WITH BASES 800-1000 FT MSL AND TOPS
TO 1500 FT MSL COULD OCCUR MAINLY 07Z-16Z THU...WITH MODERATE
CONFIDENCE OF OCCURRENCE AT KSAN/KCRQ/KSNA. THERE IS A SLIGHT CHANCE
OF THUNDERSTORMS OVER THE ENTIRE REGION TONIGHT AND THU...WITH BASES
8000 FT MSL AND TOPS TO 40000 FT MSL POSSIBLE WITH LOCAL SURFACE
WIND GUSTS OVER 30 KT AND POSSIBLE HAIL. OTHERWISE...SCT-BKN CLOUDS
AT VARIOUS HEIGHT LEVELS...MAINLY ABOVE 8000 FT MSL WILL CONTINUE
THROUGH THU.

&&

.MARINE...
845 PM...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS TONIGHT THROUGH
THURSDAY...WITH CLOUD TO WATER LIGHTNING BEING THE PRIMARY
ASSOCIATED THREAT. OTHERWISE...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...JAD
AVIATION/MARINE...MAXWELL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1041 PM PDT WED OCT 14 2015

CAZ055-060-150630-
VICTOR VALLEY - APPLE VALLEY - LUCERNE VALLEY - JOHNSON VALLEY CA-
SAN BERNARDINO COUNTY MOUNTAINS-
INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE
SAN BERNARDINO NATIONAL FOREST CA-
1041 PM PDT WED OCT 14 2015

...SPECIAL WEATHER STATEMENT...

AT 1041 PM PDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
OVER HWY 2 BETWEEN PHELAN AND WRIGHTWOOD...MOVING NORTHWEST AT 25
MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
VICTORVILLE...HESPERIA...WRIGHTWOOD...HWY 2 BETWEEN PHELAN AND
WRIGHTWOOD...I-15 THROUGH THE CAJON PASS...MOUNT BALDY...PINON
HILLS...HWY 138 BETWEEN I-15 AND HWY 2...EL MIRAGE...PHELAN AND
HIGHWAY 138 BETWEEN LLANO AND THE SAN BERNARDINO COUNTY LINE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3434 11742 3423 11759 3428 11765 3471 11767
      3474 11759
TIME...MOT...LOC 0541Z 139DEG 20KT 3435 11757

JMB