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 Phoenix, AZ wrote its last area forecast discussion before the first event at Aug 11, 9:00 PM MST, 1 hour 50 minutes earlier.
AZZ020>028-CAZ030>033-121045- SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 900 PM MST SAT AUG 11 2001 .SYNOPSIS... VERY MOIST...UNSTABLE AIR OVER SOUTH-CENTRAL AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA TRANSLATES INTO AN ONGOING POSSIBILITY OF SHOWERS AND THUNDERSTORMS ACROSS THE REGION THROUGH NEXT WEEK. .DISCUSSION... INVERTED TROUGH OVER S-CNTRL AZ PROVIDING FORCING NEEDED TO KEEP A NUMBER OF STORMS GOING OVERNIGHT. DEFORMATION AXIS AND VORTICITY FIELD ASSOCIATED WITH THE TROUGH HAS MOVED INTO S-CNTRL AZ...WITH POSITIVE VORTICITY ADVECTION WWD OVER THE CWA. THE DEFORMATION AXIS MOVES W OF THE CWA BY MON NIGHT...BUT SHOULD HELP TO FORCE STORMS BEFORE THAT. WILL MAKE MORE ADJUSTMENTS TO THE CURRENT FORECAST FOR TONIGHT...MAINLY TO TAKE OUT TIME QUALIFIERS SUCH AS EVENING. IT APPEARS TO ME THE POPS ARE A BIT LOW IN THE GUIDANCE FOR THE SW AZ AND SE CA AREAS. SW AZ AND SE CA AREAS HAVE BEEN ACTIVE THIS EVE... WITH SOME HEAVY RNFL IN SPOTS...AS WELL AS ISOLD TSTM GUSTS OVER 40 MPH. LOOK FOR THIS TYPE OF ACTION TO CONTINUE OFF AND ON UNTIL THE DEFORMATION AXIS CLEARS THAT AREA. MORE STORMS ARE DEVELOPING OVER THE NRN PHX METRO AREA AT THIS TIME. JUST GOES TO SHOW YOU. WILT
The Yuma radar (KYUX), 77 km away, was scanning. The volume nearest the first event began at 05:52 UTC.
1 flash flood. Local standard time, as filed.
Strong thunderstorms with very heavy rainfall caused flash flooding of streets and low lying areas. This event began to the northwest, in Imperial County, California, earlier in the evening.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2001Every state in 2001This day in weather historyWarnings in Arizona, August 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: 5262819.