Strong dynamics and deep moisture resulted in a significant heavy rain event. Low pressure, which developed over the central plains, moved northeast along a warm front positioned over Northern Missouri and West Central Illinois.
Every event with a place to put it; 10 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 episode as NWS DVN wrote it up.
Strong dynamics and deep moisture resulted in a significant heavy rain event. Low pressure, which developed over the central plains, moved northeast along a warm front positioned over Northern Missouri and West Central Illinois. One swath of heavy rain occurred Saturday morning and early afternoon in association with strong low level warm advection, as a strong low level jet of 60 knots through Oklahoma into South Central Kansas helped to bring deep moisture northward to destabilize the atmosphere. This resulted in an increase in coverage and intensity of the showers and thunderstorms, which deposited a widespread 1 to 2 inches of rain by late Saturday afternoon. A second round of heavy rain fell late Saturday evening through early Sunday morning, as the low pressure system moved northeast along the warm front. Storm total rainfall amounts ranged anywhere from 3 to as much as 6 inches, with isolated higher amounts of near 8 inches.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at May 11, 1:30 PM CST, 9 hours 50 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CDT SAT MAY 11 2002 WIDESPREAD 1 TO 2 INCH RAINS OVER CENTRAL AND SOUTHERN CWA SETTING STAGE FOR POSSIBILITY OF MORE FLOODING TONIGHT AND EARLY THURSDAY. LOOKS LIKE HYDRO SITUATION WILL BE MAIN CONCERN THIS ISSUANCE ALONG WITH SEVERE POTENTIAL OVERNIGHT ACROSS SOUTH. SOUTHERN CWA CURRENTLY UNDER FLOOD WATCH THROUGH TONIGHT WHERE MODELS STILL SUGGEST BEST POTENTIAL FOR ADDITIONAL HEAVY RAIN WILL BE OVERNIGHT. ALSO LOOKS LIKE MODERATE TO HEAVY RAIN POTENTIAL WILL CONTINUE INTO SUNDAY MORNING AND WILL EXTEND WATCH ACCORDINGLY. BIG DILEMA IS WHETHER TO BRING WATCH FURTHER NW WITH GROUND NOW SATURATED FROM THIS MORNINGS RAIN. FEELING IS THAT MODELS ARE ALREADY TOO FAR N WITH WARM FRONT AT 18Z...WITH CLOUDS AND RAIN-COOLED AIR NORTH OF BOUNDARY ENHANCING FRONT...MODEL POSITION ACROSS SE IA AND W CENTRAL IL IS QUESTIONABLE. WILL MONITOR FRONT AND IF THERE ISNT MUCH NORTHWARD PUSH...WILL KEEP LOCATION OF WATCH INTACT. SOME RISK OF SEVERE LATE THIS AFTERNOON AND THIS EVENING AHEAD OF SFC LOW PROGGED TO MOVE ALONG BOUNDARY ACROSS NRN MO/SRN IA THIS EVENING AND OVERNIGHT. POTENTIAL LATE TODAY WILL BE DEPENDENT ON AMOUNT OF DESTABALIZATION OVER CENTRAL MO WHERE CLOUDS ARE CURRENTLY LIMITING AFTERNOON HEATING AND WARM FRONTAL POSITION. AT THIS POINT BELIEVE SEVERE POTENTIAL IS MINIMAL AND WILL BE LIMITED TO FAR SOUTH. MODELS SIMILAR THROUGH TUESDAY PUSHING FRONT SOUTH OF AREA BY LATE SUNDAY NIGHT AS NORTHWEST FLOW DEVELOPS OVER REGION. ANOTHER WEAK S/W DROPS SOUTH THROUGH MID MISSISSIPPI VALLEY MONDAY NIGHT. FORCING AND MOISTURE LIMITED...SO NOTHING MORE THAN CLOUDS EXPECTED. WILL FAVOR COOLER MAV NUMBERS WITH COOL NW FLOW THROUGH PERIOD. .EXTENDED LONG RANGE MODELS IN CLOSER AGREEMENT FOR LATE WEEK WITH ACTIVE PATTERN CONTINUING. MODELS POINTING TO ANOTHER SIGNIFIANT RAINFALL EVENT FOR REGION THURSDAY/FRIDAY WITH ANOTHER FRONT STALLING OVER SOUTHERN CWA AND SFC LOW MOVING ALONG BOUNDARY. AVN POINTING TO SOME PCPN WEDNESDAY...BUT LOOKS WAY OVER DONE. SO...WILL GO CHANCE TSRA WED THRU SATURDAY. .DVN...FLOOD WATCH TONIGHT IA...IAZ078-087>089-098-099. IL...ILZ016>018-024>026-034-035. MO...MOZ009-010. DLF
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
845 PM CDT SAT MAY 11 2002
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0838 PM 4 N GRANGER MO .5 INCH HAIL
05/11/02 SCOTLAND REPORTED BY STORM
SPOTTER.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1115 PM CDT SAT MAY 11 2002
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1110 PM ELVASTON IL .5 INCH HAIL
05/11/02 HANCOCK REPORTED BY LAW
ENFORCEMENT OFFICIAL.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1124 PM CDT SAT MAY 11 2002
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1110 PM MEMPHIS MO FLOOD
05/11/02 SCOTLAND 4 TO 6 INCHES OF WATER
COVERING SOME OF THE
STREETS. SOME
BASEMENTS WERE ALSO
TAKING IN WATER. PARTS
OF HIGHWAY 15 NORTH OF
MEMPHIS ALSO WATER
COVERED. CREEKS IN
SOUTHERN PART OF COUNTY
WERE RUNNING ABOUT 3/4
TO BANK FULL. REPORTED
BY EMERGENCY MANAGEMENT.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1152 PM CDT SAT MAY 11 2002
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1020 PM 5 NE KAHOKA MO FLOOD
05/11/02 CLARK LOW SPOTS OF COUNTY
ROAD D AND COUNTY ROAD
K UNDER WATER AND
CLOSED. REPORTED BY
LAW ENFORCEMENT
OFFICIAL AND SKYWARN
SPOTTER.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1209 AM CDT SUN MAY 12 2002
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
1157 PM 3 S ARGYLE IA FLOOD
05/11/02 LEE 300 STREET...BETWEEN
HIGHWAY 61 AND HIGHWAY
218 IS WATER COVERED
AND MAY BE CLOSED.
EARLIER...320 STREET BY
HIGHWAY 34...ABOUT 2.5
MILES SOUTH OF
ARGYLE...WAS REPORTED
WATER COVERED. 235
STREET NEAR DEVILS
CREEK WAS ALSO REPORTED
WATER COVERED AND
LIKELY CLOSED.
REPORTED BY LAW
ENFORCEMENT OFFICIAL.The national radar mosaic for the moment the first event began.
9 flash flood, 1 flood. Local standard time, as filed.
Ellison Creek just north of the Highway 96 and 116 junction went out of it's banks and into fields. Some basements in Stronghurst were flooded. Also, Honey Creek rose out of it's banks with water covering roads near Olena.
Many roads were covered in water and impassable. Several people were stranded in their vehicles and had to be rescued.
Several roads in Carthage were covered with water up to a foot deep. One residence in a low lying area was evacuated. Water covered a large portion of Highway 136 heading west of Carthage.
7 to 8 inches of water covered Illinois route 96.
In Spring Valley, one of the two Kirby Park tennis courts was flooded, with water extending into the softball diamond outfield. The dock at the Barto Landing was also under water. A creek 2 miles northwest of Ladd overflowed it's banks, with water extending into fields. A person escaped injury as their automobile hydroplaned off Interstate 80 and overturned. Pike Road in southeast portions of the county was flooded.
Highway 136 and route 96 were covered with water and impassable in spots.
Water covering several portions of Highway 34.
Henderson Creek rose out of it's banks and flooded nearby fields.
Minor flooding reported on some secondary roads.
Water up to a foot deep covered portions of Highway 41 making it impassable.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2002Every state in 2002This day in weather historyWarnings in Illinois, May 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: 5297862, 5297863, 5297864, 5297865, 5297866, 5297867, 5297868, 5297869, 5297959, 5297960.