1 flash flood, as filed by the National Weather Service.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 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 Sep 3, 1:00 PM PST, 1 hour 30 minutes earlier.
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 200 PM PDT MON SEP 3 2001 LATEST SATELLITE INDICATES SCATTERED THUNDERSTORMS OVER THE VTU/LAX MOUNTAINS THIS AFTERNOON...ASSISTED BY WEAK UPPER LOW MOVING ACROSS THE DISTRICT. ALREADY HAVE FLASH FLOOD WARNINGS FOR VTU/SBA COUNTIES AND WILL CONTINUE TO MONITOR SITUATION THIS AFTERNOON. MODELS INDICATE UPPER LOW PUSHES EASTWARD AND UPPER FLOW TURNS SOUTHWEST TONIGHT THROUGH WEDNESDAY. SO...DO NOT ANTICIPATE ANY MOUNTAIN THUNDERSTORMS TUESDAY/WEDNESDAY. HOWEVER...MAY BE ENOUGH LINGERING MOISTURE TO PRODUCE SOME BUILDUPS TUESDAY AFTERNOON. OTHERWISE...ONLY CONCERN IS MARINE LAYER/TEMPS. MODELS INDICATE GRADUAL INCREASE IN H5 HEIGHTS THROUGH WEDNESDAY...AS UPPER HIGH BUILDS OVER SOUTHWEST U.S.. NEAR THE SURFACE...EAST-WEST ONSHORE GRADIENTS WEAKEN THROUGH WEDNESDAY...AS NORTH-SOUTH GRADIENTS TURN OFFSHORE. THESE FACTORS WILL COMBINE TO SQUASH THE MARINE LAYER NEXT COUPLE OF DAYS...WITH ONLY VERY PATCHY STRATUS/DENSE FOG EXPECTED IN THE LOWER COASTAL VALLEYS BY WEDNESDAY MORNING. AS FOR TEMPS...DUE TO INCREASING THICKNESSES/WEAKER ONSHORE FLOW AND LESS MARINE LAYER...ALL AREAS SHOULD HAVE WARMER TEMPS THROUGH WEDNESDAY WITH BEST WARMING IN THE VALLEYS. FOR EXTENDED...UPPER RIDGE WILL CONTINUE TO DOMINATE THROUGH SATURDAY...WITH WARM TEMPS AND LIMITED MARINE LAYER. UPPER FLOW REMAINS SOUTH/SOUTHWEST...SO DO NOT ANTICIPATE ANY MONSOONAL MOISTURE FILTERING IN. BY SUNDAY/MONDAY...RIDGE BREAKS DOWN AS IMPRESSIVE UPPER LOW MOVES ACROSS NORTHERN CALIFORNIA. END RESULT WILL BE COOLER TEMPS AND INCREASED MARINE LAYER. LAX 000. THOMPSON .LAX...NONE.
The Los Angeles radar (KVTX), 8 km away, was scanning. The volume nearest the first event began at 22:29 UTC.
1 flash flood. Local standard time, as filed.
Strong monsoonal thunderstorms produced heavy rain and flash flooding across the mountains of Ventura county. Lockwood Valley Road, between Highway 33 and Chico Larson Road, was closed due to flash flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2001Every state in 2001This day in weather historyWarnings in California, September 2001
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: 5263829.