Flooding in Iowa, April 1 to 30, 2001

Name: Flooding in Iowa, April 1 to 30, 2001
Start: 2001-04-01T06:00
End: 2001-04-30T23:59
Location: Iowa

April 1 to 30, 2001 · NWS FSD · 3 events in 3 counties and zones

Snowmelt and heavy rain combined to produce flooding along the Big Sioux River in early April. The flooding continued late in the month due to additional heavy rains.

Where it happened

Every event with a place to put it; 3 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 3

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 FSD wrote it up.

Snowmelt and heavy rain combined to produce flooding along the Big Sioux River in early April. The flooding continued late in the month due to additional heavy rains. The flooding reached a record crest of 23.3 feet at Akron on the 26th. Dikes and sandbagging helped the city of Akron avoid major damage, although several nearby roads were flooded. Highway 403 north of Akron was flooded after a dike broke, and several other roads near the river were flooded. Several bridges across the river from Iowa to South Dakota were closed at the height of the flooding. Farmland along the river was flooded.

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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Apr 1, 3:05 AM CST, 2 hours 55 minutes earlier.

Area forecast discussion, Apr 1, 3:05 AM CST, 2 hours 55 minutes before

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
405 AM CDT SUN APR 01 2001

FIRST PD TDAY...ONE WART TO WORRY ABOUT. AS THE WINDS SHIFT ARND TO
THE SE TDAY CWA WIDE...THE MODELS ARE BRINGING IN SOME DECENT LLVL
WAA AND MID LVL LEFT TO THE SE PTN OF THE CWA BY AFTERNOON. THIS IS
COUPLED WITH A LLVL JET THAT ISN'T REAL STRONG...BUT HAS PRETTY GOOD
SPEED CONVERGENCE. ETA IS SHOWING A LITTLE LIGHT QPF IN RESPONSE TO
THIS FOR PTNS OF NW IA...AND AGREE THAT THERE COULD BE A FEW
SPRINKLES OR LIGHT SHOWERS COMING FM MID LVL CLOUDS IN THIS AREA
LATER TDAY...RIGHT ON THE NOSE OF THE LLVL JET. THEREFORE PUT IN
SOME LOW POPS FOR MUCH OF NW IA THIS AFTN. OTHERWISE...THE CWA CAN
JUST EXPECT THE WIND TO COME ARND TO THE SE WITH INCRG CLDS FM THE
WEST.

THE WK MID LVL SHORTWV AFFECTING THE WX TDAY EXITS THE CWA TNGT...SO
OPTED TO JUST GO PARTLY CLOUDY MOST LOCATIONS AS RH TIME SECTIONS
ARE FAIRLY DRY. THEN ON MONDAY...STRONG LOW PRES STARTS TO GET
CRANKED IN THE WRN PLAINS WITH A LARGE UPR LVL TROF IN THE WEST. THE
THING TO WORRY ABOUT IS ALL MDLS BRING THE FIRST SHORTWV NEWD FROM
THE PARENT TROF THRU THE DAY ON MONDAY INTO THE FSD CWA. TREMENDOUS
MID LVL LIFT AND WAA TO WORRY ABOUT WITH SOME MID LVL FRONTOGENESIS.
HOWEVER...AS IS THE CASE TDAY...THE LYR ARND 800MB IS STILL RATHER
DRY BUT WITH PLENTY OF MSTR ABOVE IT. USING SOME QPF GUIDANCE FM THE
ETA AND AVN AND SOME PTRN RECOGNITION...USUALLY THE FIRST SHORTWVS
FM THESE LARGE TROFS AFFECT THE WRN AND SWRN PTNS OF THE CWA HARDER
THAN THE EAST. FURTHERMORE...THE LLVL AIR IS INCREASINGLY DRY
HEADING EWD. FEEL WITH THIS KIND OF SITUATION...THERE COULD BE A
BAND OF MID LVL SHOWERS WORKING SW TO NE ON MONDAY...WITH THE BEST
CHCS OVR THE SW AND WRN PTN OF THE CWA WHERE THE LLVL MSTR AND
DYNAMICS ARE BETTER. HOWEVER WITH THE DRY LLVLS...BELIEVE THE ETA
QPF IS OVERDONE. LOOKED AT ETA/AVN 850MB LI AND THINGS ARE STILL
PRETTY STABLE...SO DID NOT INCLUDE TS.

MONDAY NIGHT IS KIND OF TOUGH TO FIGURE...AVN AND ETA JUST PAINT THE
CWA WITH QPF. PARENT TROFFING STILL TO THE WEST...AND I DO NOT LIKE
THE ETA BRINGING THE LLVL LOW WAY TOO FAR TO THE E IN KANSAS. PREFER
THE AVN SOLN IN KEEPING THE LLVL LOW TO THE WEST OF THE CWA...
PULLING IN WAA AND E TO SE WINDS CONTINUING. THE ATMOSPHERE
SATURATES UP PRETTY GOOD...AND LOOKS LIKE THE BEST DYNAMICS AND
CONVERGENCE ARE ASSOCIATED WITH THE DEPARTING LIFT FM THE MONDAY
SYSTEM. THIS FAR OUT HOWEVER...TIMING AND REFINED PLACEMENT OF THE
PCPN IS DIFFICULT AND OPTED TO NOT INCLUDE ANY TIMING AS OF YET.
850MB LI PROGS ARE A LITTLE UNSTABLvE ARND KSUX SO PUT IN TS THERE.
AVN 850 TEMPS MAY ALSO BE TOO WARM...AS THEY INTIIALIZED ABOUT 2 TO
4 DEGREES TOO WARM OVER THE CWA TDAY.

DIDN'T LOOK AT THE EXTENDED WITH THE TIME CHANGE.

.FSD...NONE
 FUHS

The radar

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

Open the radar archive at this moment

Event by event

3 flood. Local standard time, as filed.

Flood, Lyon

When: April 1, 6:00 AM CST to April 30, 11:59 PM CST
Where: Lyon forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 43.381, -96.210 (the zone’s center; the record gives no point)

Flood, Plymouth

When: April 1, 6:00 AM CST to April 30, 11:59 PM CST
Where: Plymouth forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 42.738, -96.214 (the zone’s center; the record gives no point)

Flood, Sioux

When: April 1, 6:00 AM CST to April 30, 11:59 PM CST
Where: Sioux forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 43.083, -96.178 (the zone’s center; the record gives no point)

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

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

The same day elsewhere

Every storm in Iowa in 2001 Every state in 2001 This day in weather history Warnings in Iowa, April 2001

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: 5242968, 5242969, 5242970.