A push of monsoonal moisture from northern Mexico brought thunderstorms to the mountains and deserts of Ventura and Los Angeles counties. Some of the thunderstorms producing heavy rain and flash flooding.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LOX wrote it up.
A push of monsoonal moisture from northern Mexico brought thunderstorms to the mountains and deserts of Ventura and Los Angeles counties. Some of the thunderstorms producing heavy rain and flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Los Angeles, CA wrote its last area forecast discussion before the first event at Jul 22, 10:00 AM PST, 2 hours 53 minutes earlier.
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 1100 AM PDT MON JUL 22 2013 ..UPDATED AVIATION SECTION... .SYNOPSIS... A MOIST MONSOONAL FLOW WILL BRING ISOLATED SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA TODAY AND TONIGHT. HEAVY RAIN SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS AND DESERTS THIS AFTERNOON AND EVENING. ON TUESDAY THE THREAT OF SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS AND ANTELOPE VALLEY. FOR THE SECOND HALF OF THE WEEK...DRY AND WARMER CONDITIONS ARE EXPECTED. && .SHORT TERM (TODAY-WED)...GUIDANCE INITIALIZED MID/UPPER LEVEL PV CENTERED OVER THE AREA THIS MORNING AND BROAD MID/UPPER LEVEL MOISTURE FETCH EXTENDING NORTHWEST OVER THE AREA FROM MEXICO REASONABLY WELL. WIDESPREAD PRECIPITATION WITH AMOUNTS LESS THAN TENTH OF AN INCH WITH ISOLATED AMOUNTS AROUND ONE TENTH OVER SANTA YNEZ RANGE HAD OCCURRED IN THE LAST 6 HOURS AS THE SYSTEM ADVANCED NORTH AND WEST. THE WIDESPREAD RAIN HAD PUSHED NORTH OF THE AREA AT THIS TIME AND ISOLATED SHOWERS WERE OVER NORTH HALF OF THE AREA WITH CLEARING SKIES OVER THE SOUTH HALF. STABILITY DECREASES OVER THE AREA WITH THE AFTERNOON HEATING AND ISOLATED THUNDERSTORMS ARE POSSIBLE. THE STORMS WILL HAVE LITTLE MOVEMENT AND PWAT IS NEAR 2 INCHES AND FLASH FLOODING IS A THREAT OVER THE MOUNTAINS AND DESERT THROUGH THE EVENING. THE FOLLOWING IS AN EXCERPT FROM THE PREVIOUS DISCUSSION THE GREATEST THREAT OF FLASH FLOODING IS OVER THE MTNS OF LA AND VTA COUNTIES AS WELL AS THE AV WHERE THERE WILL BE THE GREATEST CHANCE FOR TSTM FORMATION. THING ARE STILL NOT ALL THAT UNSTABLE BUT THE AFOREMENTIONED MORNING SUNSHINE MIGHT ALLOW FOR ENOUGH SFC HEATING TO CREATE LOCAL INSTABILITIES. THE THREAT OF TSTMS AND SHOWERS WILL LINGER INTO THIS EVENING AND THEN NVA SHOULD CUT EVERYTHING OFF. THERE WILL BE ENOUGH CLOUDS AND SHOWERS TO KEEP MAX TEMPS WELL BELOW NORMAL (THERE IS ALSO ENOUGH CLOUDS AND HUMIDITIES TO KEEP THIS MORNINGS LOWS ABOVE NORMAL. TUESDAY WILL BE DRIER AS THE UPPER HIGH RETREATS EASTWARD. THERE WILL BE A LITTLE MORE SUNSHINE AND A SLIGHT CHANCE OF AFTERNOON TSTMS WILL CONTINUE OVER THE MTNS AND AV. THE FALLING HGTS CAUSED BY THE RETREATING UPPER HIGH WILL MOSTLY COUNTERACT THE EFFECTS OF THE INCREASED SUNSHINE AND MAX TEMPS WILL BE SIMILAR TO TODAYS. BUT THE HUMIDITIES WILL BE DOWN SO IT WILL FEEL MORE COMFORTABLE. THINGS BEGIN TO REVERT TO NORMAL WEDNESDAY. A BROAD UPPER RIDGE COVERS MOST OF THE WESTERN PORTION OF THE CONUS AND A VERY WEAK UPPER LOW WILL BE JUST TO THE WEST OF THE STATE. DRIER SSW FLOW WILL CUT OFF THE TSTMS CHC BUT THERE WILL BE SOME BUILD UPS. THE MARINE LAYER WILL STRUGGLE TO REFORM. MAX TEMPS INLAND WILL JUMP UP BUT THE COASTAL MAX TEMPS WILL NOT CHANGE MUCH. .LONG TERM (THU-SUN)... ON THURSDAY AND FRIDAY THE UPPER HIGH WILL SIT OVER THE SRN NM AND A WEAK UPPER LOW WILL CONTINUE TO SIT JUST OF THE COAST. THE UPPER FLOW WILL MOSTLY BE SW AND DRY BUT A LITTLE MOISTURE MAY BE ENTRAINED AND THE MTNS WILL SEE PARTLY CLOUDY SKIES IN THE AFTERNOON. HGTS WILL RISE TO NEAR 590 DM AND MAX TEMPS WILL CLIMB TO AND THEN EXCEED NORMALS. THE ATMOSPHERIC WARMING WILL ALLOW A BETTER INVERSION TO FORM AND THERE WILL BE A NIGHT THROUGH MORNING LOW CLOUD ACROSS THE COASTS. LARGE SCALE TROFING MOVES INTO THE AREA OVER THE WEEKEND. THIS WILL INCREASE THE MARINE LAYER AND KICK OFF A COOLING TREND. && .AVIATION...22/1800Z... SCT TO BKN MID AND UPPER LEVEL CLOUDS WILL PERSIST ACROSS THE REGION INTO THIS EVENING. EXPECT ISOLATED TO SCATTERED SHOWERS AND TSTMS THIS AFTERNOON AND EVENING...ESP IN THE MTNS OF L.A. AND VTA COUNTIES AND THE ANTELOPE VALLEY. ANY THUNDERSTORM MAY HAVE LOWER CIGS...BRIEF WIND GUSTS IN EXCESS OF 35 KT AND LOCALLY HEAVY RAIN. ATMOSPHERE WILL BEGIN TO STABILIZE AFTER 06Z. MARINE LAYER WILL BEGIN TO REFORM BY 12Z WITH PATCHY LOWER CIGS NEAR THE COAST. KLAX...LOW TO MODERATE CONFIDENCE IN 18Z TAF. THERE IS A 10-20% CHANCE OF A SHOWER OR TSTM IN THE VCNTY OF THE AIRPORT TODAY. THERE IS A 20% CHANCE THAT CONDITIONS WILL REMAIN VFR TONIGHT INTO TUE MORNING. KBUR...MODERATE CONFIDENCE IN 18Z TAF. THERE IS A 20% CHANCE OF A SHOWER OR TSTM IN THE VCNTY OF THE AIRPORT TODAY. && .LOX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH (SEE LAXFFALOX). HIGH RIP CURRENT RISK (SEE LAXSRFLOX). MARINE WEATHER STATEMENT (SEE LAXMWSLOX). && PUBLIC...30/RORKE AVIATION...SMITH SYNOPSIS...SETO WWW.WEATHER.GOV/LOSANGELES
HAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 801 AM PDT MON JUL 22 2013 CAZ034>041-044>046-051>054-059-087-088-547-548-231300- SAN LUIS OBISPO COUNTY CENTRAL COAST- SANTA BARBARA COUNTY CENTRAL COAST-SANTA YNEZ VALLEY- SAN LUIS OBISPO COUNTY INTERIOR VALLEYS-CUYAMA VALLEY- SANTA BARBARA COUNTY SOUTH COAST-VENTURA COUNTY COAST- LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES- VENTURA COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS- SANTA MONICA MOUNTAINS RECREATIONAL AREA- SAN LUIS OBISPO COUNTY MOUNTAINS- SANTA BARBARA COUNTY MOUNTAINS-VENTURA COUNTY MOUNTAINS- LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE- ANTELOPE VALLEY-CATALINA ISLAND-SANTA CLARITA VALLEY- LOS ANGELES COUNTY SAN FERNANDO VALLEY- LOS ANGELES COUNTY SAN GABRIEL VALLEY- 801 AM PDT MON JUL 22 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA. .DAY ONE... TODAY AND TONIGHT A CHANCE OF THUNDERSTORMS COULD BRING HEAVY RAIN CAPABLE OF PRODUCING FLASH FLOODING TO THE MOUNTAINS AND ANTELOPE VALLEY THROUGH THE EVENING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ELSEWHERE INCLUDING THE COASTAL WATERS. BEACHGOERS WILL FACE A THREAT OF RIP CURRENTS IN THE SURF ZONE. * FLOOD WATCH................SEE WGUS66 KLOX - FFALOX FOR DETAILS * * HIGH RIP CURRENT RISK......SEE FZUS56 KLOX - SRFLOX FOR DETAILS * * MARINE WEATHER STATEMENT...SEE FZUS76 KLOX - MWSLOX FOR DETAILS * .DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Los Angeles radar (KVTX), 44 km away, was scanning. The volume nearest the first event began at 20:52 UTC.
2 flash flood. Local standard time, as filed.
Strong thunderstorms produced heavy rain and flash flooding in the mountains of Ventura county. The California Highway Patrol reported flash flooding along the intersection of Highway 33 and Apache Canyon Road.
Strong thunderstorms produced heavy rain and flash flooding across the Antelope Valley between the communities of Llano and Pearblossom. California Highway Patrol reported numerous vehicles stuck in flood waters at the intersection of Highway 138 and 165th Street East. Also Avenue T between Pearblossom and Llano was closed due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2013Every state in 2013This day in weather historyWarnings in California, July 2013
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 467094, 467095.