Flash Flooding in Missouri, May 11 to 12, 2002

Name: Flash Flooding in Missouri, May 11 to 12, 2002
Start: 2002-05-11T21:20
End: 2002-05-12T07:00
Location: Missouri

May 11 to 12, 2002 · NWS DVN · 4 events in 2 counties and zones

Where it happened

Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 4

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.

What happened

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 7 inches, with isolated higher amounts of near 10 inches reported in Scotland County. This significant heavy rain triggered widespread flash flooding. Many roads, especially secondary roads, were covered in water and closed. Clark and Scotland Counties were designated as 2 of 60 Missouri counties eligible to receive federal disaster funds. The heavy rains did a lot of damage to county roads, bridge approaches and even some bridges in Clark County, prompting officials to apply for more than $120,000 in federal funds to help with the road and bridge repairs.

What forecasters said that day

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, 7 hours 50 minutes earlier.

Area forecast discussion, May 11, 1:30 PM CST, 7 hours 50 minutes before

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

In the hours before

Local storm report, May 11, 4:06 PM CST, 5 hours 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
506 PM CDT SAT MAY 11 2002

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0158 PM    DALLAS CITY               IL   1 INCH HAIL
05/11/02   HANCOCK                        REPORTED BY STORM
                                          SPOTTER.

Local storm report, May 11, 4:11 PM CST, 5 hours 9 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
511 PM CDT SAT MAY 11 2002

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0258 PM    DALLAS CITY               IL   1 INCH HAIL
05/11/02   HANCOCK                        REPORTED BY STORM
                                          SPOTTER.

Local storm report, May 11, 7:45 PM CST, 1 hour 35 minutes before

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.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 flash flood. Local standard time, as filed.

Flash Flood, Clark

When: May 11, 9:20 PM CST to May 12, 1:15 AM CST
Where: Clark County, 5 mi NE of Kahoka
Reported by: LAW ENFORCEMENT
Coordinates: 40.410, -91.738 (the zone’s center; the record gives no point)

Low spots of County Road D and County Road K were under water forcing them to be closed. Water also covered portions of Jefferson and Main Streets. A creek on the east side of North Jefferson Street was forced out of it's banks and nearly submerged an entire garden of a nearby residence. The water receded quickly enough that no damage was done to the garden.

Flash Flood, Scotland

When: May 11, 10:10 PM CST to May 12, 1:15 AM CST
Where: Scotland County, Memphis
Reported by: EMERGENCY MANAGER
Coordinates: 40.453, -92.147 (the zone’s center; the record gives no point)

4 to 6 inches of water covered some city streets and portions of U.S. Highway 15 north of town. The basements of some residences in town were also flooded.

Flash Flood, Clark

When: May 12, 4:23 AM CST to 7:00 AM CST
Where: Clark County, Countywide
Reported by: LAW ENFORCEMENT
Coordinates: 40.410, -91.738 (the zone’s center; the record gives no point)

Widespread flash flooding was observed throughout the county with many secondary roads water covered and closed. Also, homes in several communities had water in basements.

Flash Flood, Scotland

When: May 12, 4:23 AM CST to 7:00 AM CST
Where: Scotland County, Countywide
Reported by: LAW ENFORCEMENT
Coordinates: 40.453, -92.147 (the zone’s center; the record gives no point)

Widespread flash flooding was observed throughout the county with many secondary roads water covered and closed.

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Missouri in 2002 Every state in 2002 This day in weather history Warnings in Missouri, May 2002

Sources

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: 5299076, 5299077, 5297561, 5299078.