Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 101, NWS Des Moines, IA

August 11, 1993Marion County, Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 11, 1993, 8:57 PM CDT for Marion County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Aug 11, 1993, 8:57 PM CDT (01:57 UTC)
Expired
Aug 12, 1993, 12:00 AM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Marion County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.0 hours before the alert went out and 273 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 1993-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 613 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 1993-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
613 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
872 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDSM 120156
FFWDSM
IAC125-120500-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
857 PM CDT WED AUG 11 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL MIDNIGHT CDT
FOR PEOPLE IN THE FOLLOWING LOCATION(S)...
 
IN SOUTH CENTRAL IOWA
 
   ...MARION COUNTY
 
AT 855 PM RADAR INDICATED TORRENTIAL RAIN PRODUCING THUNDERSTORMS IN
MARION COUNTY. 4.25 INCHES OF RAIN HAS OCCURRED IN INDIANOLA DURING THE
LAST TWO HOURS.
 
SOME STREAMS IN THE WARNING AREA ARE...LONG
BRANCH...ENGLISH...HICKORY...AND THUNDER CREEKS.
 
SOME CITIES IN THE WARNING AREA...PLEASANTVILLE...KNOXVILLE...AND HARVEY 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 11, 5:55 PM CDT, 3 hours 2 minutes before
IAZALL-120130-

SPECIAL WEATHER STATEMENT...SPELLING CORRECTION
NATIONAL WEATHER SERVICE DES MOINES IA
555 PM CDT WED AUG 11 1993

...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL BE MOVING ACROSS CENTRAL
IOWA THIS EVENING...

STRONG THUNDERSTORMS...CAPABLE OF PRODUCING VERY HEAVY RAINFALL IN A
SHORT PERIOD OF TIME WILL BE TRACKING ACROSS CENTRAL IOWA...INCLUDING
THE DES MOINES METRO AREA BETWEEN 6 AND 8 PM THIS WEDNESDAY EVENING.
AS THE STORMS MOVED ACROSS GUTHRIE COUNTY IN WEST CENTRAL IOWA...NEARLY
A FOOT OF WATER WAS OVER HIGHWAY 295 NEAR THE TOWN OF MENLOW...OR ABOUT
40 MILES WEST OF DES MOINES. IN ADDITION...NEARLY 3 INCHES OF RAIN FELL
IN A LITTLE OVER AN HOUR AND A HALF IN THE TOWN OF ANITA IN CASS COUNTY
...OR 60 MILES WEST OF DES MOINES.

THE THUNDERSTORMS WERE MOVING TO THE NORTHEAST AT 25 MILES AN HOUR
WITH ADDITIONAL DEVELOPMENT OCCURRING TO THE WEST OF THIS AREA. RAINFALL
AMOUNTS MAY EXCEED 3 INCHES IN ISOLATED AREAS OF CENTRAL IOWA AS THE
THUNDERSTORMS MOVE ACROSS CENTRAL AND SOUTH CENTRAL IOWA THIS EVENING.

IF YOU SEE WATER OVER A ROADWAY...DO NOT ATTEMPT TO DRIVE THROUGH IT.
IF YOU LIVE NEAR A FLOOD PRONE CREEK OR STREAM...BE PREPARED TO MOVE
TO A PLACE OF SAFETY.

SMITH
Special weather statement, Aug 11, 5:55 PM CDT, 3 hours 2 minutes before
IAZALL-120130-

SPECIAL WEATHER STATEMENT...SPELLING CORRECTION
NATIONAL WEATHER SERVICE DES MOINES IA
555 PM CDT WED AUG 11 1993

...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL BE MOVING ACROSS CENTRAL
IOWA THIS EVENING...

STRONG THUNDERSTORMS...CAPABLE OF PRODUCING VERY HEAVY RAINFALL IN A
SHORT PERIOD OF TIME WILL BE TRACKING ACROSS CENTRAL IOWA...INCLUDING
THE DES MOINES METRO AREA BETWEEN 6 AND 8 PM THIS WEDNESDAY EVENING.
AS THE STORMS MOVED ACROSS GUTHRIE COUNTY IN WEST CENTRAL IOWA...NEARLY
A FOOT OF WATER WAS OVER HIGHWAY 295 NEAR THE TOWN OF MENLOW...OR ABOUT
40 MILES WEST OF DES MOINES. IN ADDITION...NEARLY 3 INCHES OF RAIN FELL
IN A LITTLE OVER AN HOUR AND A HALF IN THE TOWN OF ANITA IN CASS COUNTY
...OR 60 MILES WEST OF DES MOINES.

THE THUNDERSTORMS WERE MOVING TO THE NORTHEAST AT 25 MILES AN HOUR
WITH ADDITIONAL DEVELOPMENT OCCURRING TO THE WEST OF THIS AREA. RAINFALL
AMOUNTS MAY EXCEED 3 INCHES IN ISOLATED AREAS OF CENTRAL IOWA AS THE
THUNDERSTORMS MOVE ACROSS CENTRAL AND SOUTH CENTRAL IOWA THIS EVENING.

IF YOU SEE WATER OVER A ROADWAY...DO NOT ATTEMPT TO DRIVE THROUGH IT.
IF YOU LIVE NEAR A FLOOD PRONE CREEK OR STREAM...BE PREPARED TO MOVE
TO A PLACE OF SAFETY.

SMITH
Special weather statement, Aug 11, 6:27 PM CDT, 2 hours 30 minutes before
IAC123-C125-150000-

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
627 PM CDT WED AUG 11 1993

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR MAHASKA COUNTY
UNTIL 645 PM...

...THE SEVERE THUNDERSTORM WARNING FOR MARION COUNTY EXPIRED AT 630
PM...

AT 625 PM...A SEVERE THUNDERSTORM WAS NEAR OSKALOOSA IN CENTRAL
MAHASKA COUNTY.  THE THUNDERSTORM WAS MOVING SOUTHEAST AT 25 MPH AND
IT WILL MOVE THROUGH OSKALOOSA AND FREEMONT BY 645 PM.

THE THUNDERSTORMS WERE EAST OF MARION COUNTY AND THE WARNING WILL BE
ALLOWED TO EXPIRE.

THESE THUNDERSTORMS HAVE A HISTORY OF PRODUCING VERY HEAVY
RAIN...STRONG AND DAMAGING WINDS AND HAIL.  IF YOU ARE IN THE PATH OF
THESE STORMS...MOVE TO SAFE INDOOR SHELTER.

JOHNSON
Special weather statement, Aug 11, 6:50 PM CDT, 2 hours 7 minutes before
IAZALL-120045-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
650 PM CDT WED AUG 11 1993

AT 635 PM CDT...INTENSE THUNDERSTORMS CONTINUED OVER WEST CENTRAL AND
CENTRAL IOWA.  THE STORMS WERE OCCURRING FROM 35 MILES NORTHWEST TO
45 MILES SOUTHWEST OF DES MOINES...IN A 20 MILE WIDE BAND CENTERED FROM
PERRY TO JUST SOUTH OF GREENFIELD.  THESE STORMS WERE PRODUCING
EXTREMELY HEAVY RAIN...FREQUENT LIGHTNING...AND POSSIBLY GUSTY WINDS
AND SMALL HAIL.  IF YOU ARE IN THE PATH OF THESE STORMS SEEK SHELTER
IMMEDIATELY.

THE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND THUNDERSTORMS
LOCATED GENERALLY SOUTH OF A LINE EXTENDING FROM COUNCIL BLUFFS...TO
FORT DODGE...TO BURLINGTON.

MOVEMENT OF THE STORMS AND SHOWERS WAS NORTHEAST AT AROUND 25 MILES AN
HOUR.

KALLMAN
Special weather statement, Aug 11, 7:48 PM CDT, 1 hour 9 minutes before
IAZALL-120145-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
748 PM CDT WED AUG 11 1993

AT 730 PM CDT...ISOLATED VERY STRONG THUNDERSTORMS WERE OCCURRING OVER
SOUTHWEST...CENTRAL AND SOUTHEAST IOWA.  THE STORMS WERE LOCATED IN A
20 MILE WIDE BAND EXTENDING FROM 45 MILES SOUTHWEST OF DES MOINES NEAR
GREENFIELD...TO NEAR DES MOINES...TO 20 MILES SOUTHEAST OF DES MOINES
NEAR MONROE.  ANOTHER VERY STRONG STORM WAS LOCATED JUST EAST OF
OTTUMWA.  THESE STORMS WERE PRODUCING TORRENTIAL RAINFALL...WIND GUSTS
TO 30 MILES AN HOUR...NEARLY CONTINUOUS LIGHTNING AND POSSIBLY SMALL
HAIL.  IF YOU ARE IN THE PATH OF THESE STORMS SEEK SHELTER IMMEDIATELY.

THE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND THUNDERSTORMS
OCCURRING GENERALLY SOUTHWEST OF A LINE FROM 35 MILES WEST OF FORT
DODGE NEAR SAC CITY...TO 35 MILES SOUTHWEST OF WATERLOO NEAR
MARSHALLTOWN...TO BURLINGTON.

MOVEMENT OF THE STORMS AND SHOWERS WAS EAST AT AROUND 25 MILES AN HOUR.

KALLMAN
Special weather statement, Aug 11, 8:50 PM CDT, 7 minutes before
IAZALL-120245-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
850 PM CDT WED AUG 11 1993

AT 835 PM CDT...VERY STRONG THUNDERSTORMS PRODUCING VERY HEAVY RAIN
CONTINUED OVER SOUTHWEST...CENTRAL AND SOUTHEAST IOWA.  ONE AREA OF
STORMS WAS 20 MILES WIDE EXTENDING FROM 70 MILES SOUTHWEST OF DES MOINES
NEAR BEDFORD...TO 30 MILES SOUTHEAST OF DES MOINES NEAR KNOXVILLE...TO
30 MILES NORTHEAST OF DES MOINES.  OTHER STRONG STORMS WERE 20 MILES
NORTHEAST OF OTTUMWA NEAR SIGOURNEY AND 20 MILES NORTHWEST OF BURLINGTON
NEAR MOUNT PLEASANT.  THESE STORMS WERE PRODUCING TORRENTIAL RAIN...
NEARLY CONTINUOUS LIGHTNING...WINDS TO 30 MILES AN HOUR AND POSSIBLY
SMALL HAIL.  THE EXTREME RAINFALL WILL CAUSE FLOODING...ESPECIALLY IN
URBAN AND LOW-LYING AREAS.

THE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND THUNDERSTORMS
OCCURRING SOUTH AND EAST OF A LINE FROM SHENANDOAH...TO FORT DODGE...
TO DAVENPORT.  SHENANDOAH IS 40 MILES SOUTHEAST OF COUNCIL BLUFFS.

THE STORMS AND SHOWERS WERE MOVING EAST AT AROUND 25 MILES AN HOUR.

KALLMAN

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 7:04 PM CDTFlash Flood WarningDMXDallas116 min
Aug 11, 7:31 PM CDTFlash Flood WarningDMXPolk, Warren3 hr
Aug 11, 8:09 PM CDTFlash Flood WarningDMXJasper3 hr
Aug 11, 9:47 PM CDTFlash Flood WarningDMXMahaska, Poweshiek119 min

Nearby

Flash Flood Warnings in Iowa, 1993Every flash flood warning in 1993

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.