Flash Flood Warning 66, NWS San Diego, CA

677 
WGUS76 KSGX 042011
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
111 PM PDT WED SEP 4 2013

CAC065-042330-
/O.CON.KSGX.FF.W.0066.000000T0000Z-130904T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
111 PM PDT WED SEP 4 2013

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR
WESTERN RIVERSIDE COUNTY...

AT 101 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE HEAVY RAIN CAPABLE OF PRODUCING FLASH FLOODING OVER THE 
WARNED AREA. HEAVY RAIN MAY ALSO TRIGGER DEBRIS FLOWS IN AND BELOW 
THE MOUNTAIN AND SILVER FIRE BURN AREAS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO VALLE 
VISTA...EAST HEMET AND BANNING. THE WARNING ALSO INCLUDES HIGHWAYS 
79...74...371...243...AND INTERSTATE 10 THROUGH THE BANNING PASS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WATERSHEDS BURNED IN 2013 WITHIN THE SILVER BURN AREA ARE
PARTICULARLY SUSCEPTIBLE TO FLASH FLOODS AND DEBRIS FLOWS FROM THIS
RAINSTORM. DWELLINGS...ROADS...TRAILS...AND CAMPGROUNDS LOCATED ALONG
DRAINAGES WITHIN OR BELOW THE BURNED BASINS CAN BE IMPACTED BY FLASH
FLOODS AND DEBRIS FLOWS. THIS INCLUDES...BUT IS NOT RESTRICTED TO...
ALL DWELLINGS...ROADS...CAMPGROUNDS...AND INFRASTRUCTURE IN LOW LYING
AREAS NEAR ONE HORSE CANYON AND JENSON CREEK. DWELLINGS DOWNSTREAM OF
THE BURN AREA...INCLUDING THOSE IN THE MORONGO INDIAN RESERVATION...
SNOW CREEK...HURLEY FLAT...TWIN PINES RANCH...MCMULLEN FLAT...MOUNT
OAK BOYS RANCH...POPPET FLAT...AND PORTIONS OF BANNING SOUTH OF I-10
AND ADJACENT TO THE BURN AREA. IN ADDITION...ROADS THAT MAY BE
AFFECTED INCLUDE...BUT ARE NOT LIMITED TO...THOSE IN THE VICINITY OF
BANNING IDYLLWILD ROAD...HIGHWAY 243...ESPERANZA AVENUE...ROADS IN
THE MORONGO INDIAN RESERVATION SOUTH OF MARGARET AND ESTHER
AVENUES...ROADS IN THE VICINITY OF POPPET FLATS ROAD...OLD IDYLLWILD
ROAD...ELLIS DRIVE...TWIN PINES ROAD...GORGONIO VIEW ROAD...
WONDERVIEW ROAD...VISTA GRADE ROAD OR FS 3S09...HALLS GRADE ROAD...
SILVER CREEK DRIVE AND WOLFSKILL TRUCK TRAIL. FOR MORE INFORMATION ON
POST-FIRE DEBRIS FLOWS AND WHAT TO DO IF YOU LIVE NEAR A RECENTLY
BURNED AREA...GO TO LANDSLIDES.USGS.GOV/RESEARCH/WILDFIRE/

WATERSHEDS BURNED IN 2013 WITHIN THE MOUNTAIN BURN AREA ARE
PARTICULARLY SUSCEPTIBLE TO FLASH FLOODS AND DEBRIS FLOWS FROM THIS
RAINSTORM. DWELLINGS...ROADS...TRAILS...AND CAMPGROUNDS LOCATED ALONG
DRAINAGES WITHIN OR BELOW THE BURNED BASINS CAN BE IMPACTED BY FLASH
FLOODS AND DEBRIS FLOWS. THIS INCLUDES...BUT IS NOT RESTRICTED TO...
ALL DWELLINGS...ROADS...CAMPGROUNDS...AND INFRASTRUCTURE IN LOW LYING
AREAS OF TAQHUITZ CREEK...ANDREAS CANYON...MURRAY CANYON...WEST FORK
PALM CANYON...FOBES CANYON...APPLE CANYON...HERKEY CREEK AND
COLDWATER CREEK. IN ADDITION...ROADS THAT MAY BE AFFECTED INCLUDE...
BUT ARE NOT LIMITED TO...THOSE IN THE VICINITY OF SOUTH PALM CANYON
DRIVE...HIGHWAY 74...OR PINES TO PALMS HIGHWAY...BETWEEN MOUNTAIN
CENTER AND MORRIS RANCH ROAD...FOBES RANCH ROAD APPLE CANYON ROAD...
BONITA VISTA ROAD...FOREST SERVICE 5521 AND FOREST SERVICE 5505. FOR
MORE INFORMATION ON POST-FIRE DEBRIS FLOWS AND WHAT TO DO IF YOU LIVE
NEAR A RECENTLY BURNED AREA...GO TO
LANDSLIDES.USGS.GOV/RESEARCH/WILDFIRE/

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3395 11696 3395 11664 3345 11660 3346 11693

$$

SS

062 
WGUS76 KSGX 042323
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
423 PM PDT WED SEP 4 2013

CAC065-042331-
/O.EXP.KSGX.FF.W.0066.000000T0000Z-130904T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
423 PM PDT WED SEP 4 2013

...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 PM PDT FOR WESTERN
RIVERSIDE COUNTY...

STORMS HAVE DISSIPATED OVER THE WARNED AREA. VERY LIGHT RAIN MAY 
CONTRIBUTE TO MINOR ADDITIONAL RUNOFF. HOWEVER...THE THREAT OF FLASH 
FLOODING HAS ENDED AND THE FLASH FLOOD WARNING WILL BE ALLOWED TO 
EXPIRE AT 430 PM.

LAT...LON 3395 11696 3395 11664 3345 11660 3346 11693

$$

SS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1005 AM PDT WED SEP 4 2013

.SYNOPSIS...
HOT AND MUGGY CONDITIONS WILL REDEVELOP OVER SOUTHERN CALIFORNIA FOR
THE END OF THE WORK WEEK...AS HIGH PRESSURE STRENGTHENS INTO THE
REGION.  A SHALLOW MARINE LAYER WILL HELP MODERATE TEMPERATURES
ALONG THE COAST THOUGH...WHILE INLAND AREAS RANGE 5 TO 10 DEGREES
ABOVE NORMAL.  SUBTROPICAL MOISTURE WILL ALSO CONTINUE TO SPREAD
INTO THE SOUTHLAND THROUGH THE WEEK...WITH THE THREAT OF AFTERNOON
SHOWERS AND THUNDERSTORMS CONTINUING IN THE MOUNTAINS AND DESERTS.

&&

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

TODAY...
MADE SOME CHANGES TO THE GRIDS AND SENT UPDATED FORECASTS TO SHOW
MORE AREAL COVERAGE OF THUNDERSTORMS...A LITTLE FURTHER WEST OF
MOUNTAINS DUE TO SHIFT IN TRANSPORT WINDS TO THE SOUTHEAST AND
APPROACH OF OUTFLOW BOUNDARY FROM MASSIVE NOT SO MESOSCALE
CONVECTIVE COMPLEX THAT OCCURRED OVER SONORA...SINALOA...GULF OF
CALIFORNIA...AND BAJA CALIFORNIA...AND HAS NOW TURNED THE CORNER AND
HEADING NORTHWEST. HAD A LINE OF ALTOCUMULUS CASTELLANUS ALONG THE
PENINSULAR RIDGE LINE AT SUNRISE...AT 0935 PDT COULD VISUALLY SEE
THE OVERSHOOTING TOPS IN REFORMED COMPLEX MOVING INTO IMPERIAL
COUNTY. THE 04/15Z HRRR MODEL HAS FINALLY PICKED UP ON THIS...NONE
OF THE OTHER MODELS DID. WORSE YET IT SHOWS THE THUNDERSTORMS
DEVELOPING ALONG THE ELSINORE CONVERGENCE ZONE THIS AFTERNOON...SO
MAY NEED ANOTHER UPDATE TO SPREAD THE THUNDERSTORMS EVEN FURTHER
WEST. THE GOOD NEWS...IF ANY ...IN ALL THIS IS THE AIR MASS IN THE
-10C TO -20C LAYER IS DRIER THAN YESTERDAY AND THE OVERALL COLUMN
LOOKS DRIER ALTHOUGH THE PRECIPITABLE WATER AND THE CAPE VALUES WERE
ESSENTIALLY THE SAME...SO AT LEAST INITIALLY THROUGH EARLY AFTERNOON
THE ICE/HAIL PRODUCTION SHOULD BE LESS...AND THE WIDESPREAD HEAVY
RAIN LEADING TO FLASH FLOODING WOULD BE LESS...AGAIN ASSUMING NO AIR
MASS CHANGE THIS AFTERNOON...WHICH IS LOOKING LIKE A SHAKY
ASSUMPTION THIS MORNING.

OTHERWISE THE FORECAST LOOKS GOOD ESPECIALLY WITH THE WARMER
TEMPERATURES TODAY AND AGAIN THURSDAY. SO FAR TEMPS ARE FORECAST
JUST BELOW HEAT ADVISORY CRITERIA.

EXCERPTS FROM THE EARLY MORNING DISCUSSION FOLLOW...

WATER VAPOR IMAGERY CONTINUES TO SHOW AN ELONGATED TROUGH OF LOW
PRESSURE ALONG THE WEST COAST AND HIGH PRESSURE CENTERED OVER
COLORADO.  AT THIS TIME...SOUTHERN CALIFORNIA REMAINS UNDER THE
INFLUENCE OF THIS HIGH PRESSURE SYSTEM...WHICH WILL GRADUALLY
STRENGTHEN OVER THE NEXT COUPLE OF DAYS.  AS A RESULT...HOT
CONDITIONS WILL DEVELOP ACROSS THE INLAND AREAS...WITH TEMPERATURES
RANGING 5 TO 10 DEGREES ABOVE NORMAL.  A FEW OF THE WARMEST SPOTS
MAY BE EVEN HOTTER...TOPPING OUT AT 15 DEGREES ABOVE NORMAL.  THAT
BEING SAID...IT DOES NOT APPEAR THAT ANY RECORDS WILL BE BROKEN AT
THIS TIME...SO WILL JUST HIGHLIGHT THE HEAT WITH A SPECIAL WEATHER
STATEMENT.  THE OTHER MAIN CONCERN FOR TODAY WILL BE WITH THE THREAT
OF AFTERNOON SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS AND
DESERTS...

THE OVERALL PATTER WILL CHANGE OVER THE NEXT COUPLE OF DAYS...SO HOT
CONDITIONS WILL LIKELY PREVAIL ACROSS THE INLAND AREAS...WITH
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE IN THE
MOUNTAINS AND DESERTS.  THE TROUGH WILL THEN MOVE INLAND ACROSS THE
THE PACIFIC NORTHWEST LATE FRIDAY AND INTO THE WEEKEND.  THIS WILL
BRING SOME RELIEF TO THE HOT WEATHER...AS A GRADUAL COOLING TREND
DEVELOPS.  HOWEVER...THE MODELS CONTINUE TO INDICATE THE POTENTIAL
FOR AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS AND
DESERTS.  THE MODELS START TO DEVIATE A BIT FOR EARLY NEXT
WEEK...BUT IT APPEARS THAT AN UPPER LEVEL DISTURBANCE WILL DEVELOP
OFF OR ALONG THE SOUTHERN CALIFORNIA COAST.  THE PLACEMENT OF THIS
DISTURBANCE WILL ULTIMATELY DICTATE OUR WEATHER...BUT FOR NOW...WILL
CONTINUE WITH THE THREAT OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS AND DESERTS AND MORE SEASONAL TYPE TEMPERATURES
PREVAILING.

&&

.AVIATION...
041515Z...COAST/VALLEYS...FEW-SCT CLDS AOA 9000 FT MSL DURING THE
1900-05/0300 UTC TIME-PERIOD. ALSO...SLIGHT CHANCE OF FOG REACHING
KSAN...KCRQ...AND/OR KSNA DURING THE 05/1100-1500 UTC
TIME-FRAME...BUT CONFIDENCE IS LOW. OTHERWISE...MOSTLY UNRESTRICTED
VIS/CIGS THROUGH THURSDAY MORNING.

MTNS/DESERTS...SCATTERED THUNDERSTORMS DURING THE 1800-05/0300 UTC
TIME-PERIOD WITH BASES 7000-10000 FT MSL AND CB TOPS TO 45000 FT
MSL...RESULTING IN LOCAL VIS AOB 2SM IN HEAVY RAIN...SMALL
HAIL...AND POSSIBLE STRONG UP/DOWNDRAFTS. OTHERWISE...UNRESTRICTED
VIS THROUGH THURSDAY MORNING.

&&

.FIRE WEATHER...
NEAR RECORD HIGH TEMPERATURES BUT ENOUGH MOISTURE IN AIR TO KEEP MIN
RELATIVE HUMIDITY VALUES AT OR ABOVE 25 PERCENT. MARINE LAYER DEPTH
WILL GENERALLY STAY NEAR OR BELOW 700 FEET. THREAT OF DRY LIGHTING
WEST OF MOUNTAINS THIS AFTERNOON...ALTHOUGH THAT MAY BE JUST A
TEMPORARY TRANSITION TO WET THUNDERSTORMS DURING THE LATER
AFTERNOON. ISSUED UPDATE TO FIRE WEATHER PLANNING FORECAST TO SHOW
MORE THUNDERSTORM COVERAGE...HIGHER LAL...THREAT OF HEAVY RAIN
OVER/NEAR MOUNTAINS AND DESERTS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

PUBLIC/FIRE WEATHER...JT/BALFOUR
AVIATION/MARINE...HARRISON/PIERCE
SHORT TERM WARNINGS...JJT/JT

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SAN DIEGO CA
1215 PM PDT WED SEP 4 2013

CAZ055>058-060>062-051115-
SAN BERNARDINO COUNTY MOUNTAINS-RIVERSIDE COUNTY MOUNTAINS-
SAN DIEGO COUNTY MOUNTAINS-APPLE AND LUCERNE VALLEYS-COACHELLA
VALLEY-SANTA ANA MOUNTAINS AND FOOTHILLS-SAN DIEGO COUNTY DESERTS-
1215 PM PDT WED SEP 4 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

FLASH FLOOD WATCH UNTIL 10 PM THIS EVENING...MAINLY ALONG AND EAST
OF INTERSTATE 15 IN SAN BERNARDINO COUNTY...ALONG AND SOUTH OF
INTERSTATE 10 AND HIGHWAY 91 AND 60 CORRIDORS IN RIVERSIDE COUNTY...
THE EAST SIDE OF THE SANTA ANA MOUNTAINS AND FOOTHILLS...
AND EAST OF INTERSTATE 15...HIGHWAY 67...AND HIGHWAY 125 IN SAN
DIEGO COUNTY.

THUNDERSTORMS WITH BRIEF HEAVY RAIN AND STRONG GUSTY WINDS ARE
LIKELY IN THESE AREAS...WITH A HIGH PROBABILITY OF FLASH FLOODING
AND DEBRIS FLOWS ON AND DOWNSTREAM OF RECENTLY BURNED AREAS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE MOUNTAINS AND DESERTS EACH DAY. THESE THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING LOCALIZED HEAVY RAINS...SMALL
HAIL...GUSTY WINDS...FREQUENT LIGHTNING.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER ACTIVATION MAY BE REQUESTED TODAY.

CAZ048-051115-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
1215 PM PDT WED SEP 4 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

FLASH FLOOD WATCH UNTIL 10 PM THIS EVENING...MAINLY FROM  INTERSTATE
15 AND EASTWARD. THUNDERSTORMS WITH BRIEF HEAVY RAIN AND GUSTY WINDS
LIKELY...ESPECIALLY NEAR THE SAN JACINTO MOUNTAINS AND ALONG AND
SOUTH OF HIGHWAYS 60 AND 91. VERY WARM CONDITIONS ELSEWHERE ACROSS
THE INLAND EMPIRE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...VERY WARM
CONDITIONS WILL DEVELOP ACROSS THE INLAND VALLEYS THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER ACTIVATION IS NOT REQUESTED FOR THIS AREA...
HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
WEATHER CONDITIONS.

CAZ050-051115-
SAN DIEGO COUNTY VALLEYS-
405 AM PDT WED SEP 4 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...VERY WARM
CONDITIONS WILL DEVELOP ACROSS THE INLAND VALLEYS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...VERY WARM
CONDITIONS WILL DEVELOP ACROSS THE INLAND VALLEYS THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER ACTIVATION IS NOT REQUESTED FOR THIS AREA...
HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
WEATHER CONDITIONS.

CAZ042-043-051115-
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS-SANTA ANA
405 AM PDT WED SEP 4 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...VERY WARM
CONDITIONS WILL DEVELOP ACROSS THE INLAND AREAS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. HOWEVER...VERY WARM
CONDITIONS WILL DEVELOP ACROSS THE INLAND AREAS THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...
SKYWARN WEATHER ACTIVATION IS NOT REQUESTED FOR THIS AREA...
HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
WEATHER CONDITIONS.

PALMER/BALFOUR