6 flash flood, as filed by the National Weather Service.
Every event with a place to put it; 6 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 Twin Cities, MN wrote its last area forecast discussion before the first event at Aug 20, 2:25 PM CST, 5 hours 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 325 PM CDT TUE AUG 20 2002 FIRST CONCERN FOR TONIGHT WILL BE SVR WX POTENTIAL FOR THIS EVENING...THEN HEAVY RAIN TONIGHT. MAIN WARM FRONT STILL LOOPS SEWD FROM WYOMING LOW INTO SRN MO...BUT LATEST COUPLE OF SFC MAPS SUGGEST NEW WARM FRONT IS DEVELOPING ACRS FAR SRN SD INTO NW IOWA. ELEVATED STORMS ATTM FROM NERN SD INTO SWRN MN...MOST REPORTS WILL BE HAIL. HOWEVER WITH THE DEVELOPING FRONT MOVING INTO SW MN...AGREE WITH LATEST SWODY1 ABOUT THE TORNADO POSSIBILITY AND THE UPGRADE TO MDT RISK. NEW WARM FRONT IS IN GOOD ACCORDANCE WITH 12Z MODELS...THO ETA AND AVN DISAGREE ABOUT HOW FAR NORTH THE FRONT WILL GO. LATEST RUC BRINGS IT TO A VVV/MSP LINE BY 06Z. ITS EVENTUAL POSITION WILL CERTAINLY DEPEND ON WHERE MCS SETS UP...HOLDING THE WARM FRONT FROM ANY PHANTOM LEAPS NORTHWARD. LOW LEVEL JET WILL STRENGTHEN AND GRADUALLY SHIFT EWD OVERNIGHT. BEST INFLOW NEAR FRONT WILL EXTEND FROM WC MN TO MSP. WITH LOW FLASH FLOOD GUIDANCE IN A NUMBER OF COUNTIES...FLOOD WATCH IS MERITED TONIGHT. BEST INFLOW DOES NOT REACH THE EAU CLAIRE AREA UNTIL LATE WEDNESDAY MORNING...AND BY THEN THE MCS MAY BE DIMINISHING...NOT TO MENTION MODIFYING THE FRONTAL PLACEMENT. WL THEREFORE HOLD OFF EXTENDING THE FLOOD WATCH INTO EAU CLAIRE. ONCE SYSTEM GOES BY...FRONT LAYS DOWN IN A SW/NE FASHION AND EXITS OUR SERNMOST COUNTIES TMRW AFTERNOON/EVENING. CNDN HIGH COMES ON DOWN WED NIGHT AND THURSDAY...BUT THEN THE WRN END OF FRONT COMES BACK A LITTLE...WITH ANOTHER LOW PROGGED TO TREK ACROSS NRN IOWA. WL PUSH POPS BACK TO THU NITE AND FRIDAY OVER SRN HALF OF FORECAST AREA. AFTER THAT GOES BY...WRN RIDGE BUILDS UP AND TROF DVLPS DOWN INTO THE GREAT LAKES REGION. COLD AIR ALOFT COULD PROMPT A FEW SHOWERS OR EVEN SOME THUNDER ON SATURDAY IN WESTERN WISCONSIN. OTHERWISE DRY AND QUIET FOR REMAINDER OF FORECAST. .MSP...FLOOD WATCH TONIGHT FOR ALL OF CWA EXCEPT RPD/EAU AND FRM/AEL KRAUSE
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
511 PM CDT TUE AUG 20 2002
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0350 PM 5 N BURR MN .75 INCH HAIL
08/20/02 YELLOW MEDICINE REPORTED BY STORM
SPOTTER.The Minneapolis radar (KMPX), 159 km away, was scanning. The volume nearest the first event began at 02:01 UTC.
6 flash flood. Local standard time, as filed.
Six to eight inches of rain fell within five hours, due to thunderstorms continually developing along an east-west boundary from Montevideo to the Clara City area. Streets were flooded with two to three feet of water in the lower sections of Montevideo. Numerous basements were also flooded.
Six to eight inches were measured across much of southern and eastern Lac Qui Parle County. Several streets were flooded in Dawson, stalling a few vehicles. A few basements were also flooded in Dawson.
Nearly seven inches of rain fell in extreme northeastern Yellow Medicine County, on the southern outskirts of Montevideo. Three roads were flooded with two to three feet of water, and a few basements were flooded.
Four to six inches of rain fell over saturated ground, as thunderstorms continually developed along a nearly stationary boundary. Several roads were flooded. Two county roads were barricaded: 4 miles southwest of Litchfield and 3 miles south of Kingston. Some washout damage was also noted.
Three to five inches of rain fell within a few hours, causing street flooding across the northwest half of Hennepin County. One to two feet of water was over the roads from Maple Grove and Brooklyn Park... to Plymouth... to Medina and St. Bonifacious. A few basements were also flooded.
Three to six inches of rain fell within four hours. Some streets were flooded with two to three feet of water from Waconia and Victoria to Chaska and Norwood-Young America. Ditches overflowed in Chaska, and a few roads partially washed out. Numerous basements were flooded, and some sandbagging was necessary in Chaska.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2002Every state in 2002This day in weather historyWarnings in Minnesota, August 2002
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: 5314446, 5314447, 5314448, 5314519, 5314520, 5314521.