Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 74, NWS Des Moines, IA

July 17, 1993Marshall County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 17, 1993, 2:00 PM CDT for Marshall County, Iowa. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jul 17, 1993, 2:00 PM CDT (19:00 UTC)
Expired
Jul 17, 1993, 6:00 PM CDT
In force
4 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Marshall County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.0 hours before the alert went out and 291 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 12:00Z on 1993-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1223 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 12:00Z on 1993-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 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
1223 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
1195 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 171900
FFWDSM
IAC127-172300-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
200 PM CDT SAT JUL 17 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  600 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION(S)...
 
IN CENTRAL IOWA
 
   ...MARSHALL COUNTY
 
AT 145 PM CDT OFFICIALS IN THE CITY OF MARSHALLTOWN REPORTED THAT LINN
CREEK HAD RISEN SEVERAL FEET DURING THE PAST TWO HOURS UPSTREAM...OR
WEST OF...MARSHALLTOWN. HEAVY RAINFALL OVER THE COUNTY THIS MORNING HAS
RESULTED IN RAPID RISES IN ALL CREEKS AND STREAMS IN THE COUNTY.
 
WATER LEVELS UPSTREAM OF MARSHALLTOWN WERE REPORTED TO BE AS HIGH OR
HIGHER THAN THOSE OF LAST WEEKEND.  PEOPLE IN THE NORTHEAST PART OF
MARSHALLTOWN SHOULD BE ESPECIALLY CONCERNED AND KEEP WATCH AS THIS
INCREASE IN WATER LEVEL COULD OVERTOP THE LEVEE BY LATER THIS AFTERNOON.
 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE< UP 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, Jul 17, 10:37 AM CDT, 3 hours 23 minutes before
IAZALL-171640-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1038 AM CDT SAT JUL 17 1993

AT 1025 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS...PRODUCING
EXTREMELY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLE SMALL HAIL...
CONTINUED OVER PARTS OF NORTHEAST INTO EAST CENTRAL IOWA.  THESE
STORMS WERE LOCATED IN A 25 MILE WIDE AREA...CENTERED FROM 15 MILES
SOUTHEAST OF WATERLOO...TO 5 MILES SOUTHEAST OF CEDAR RAPIDS.

THE THUNDERSTORMS WERE PART OF AN AREA OF SHOWERS AND STORMS COVERING
MUCH OF THE NORTH HALF OF IOWA.  THE STORMS AND SHOWERS WERE LOCATED
GENERALLY NORTH OF A LINE FROM 25 MILES NORTH OF COUNCIL BLUFFS/OMAHA
...TO 50 MILES NORTH OF DES MOINES...NEAR JEWELL..TO 50 MILES EAST OF
DES MOINES...NEAR GRINNEL...TO DAVENPORT/MOLINE.

THE STORMS AND SHOWERS WERE MOVING NORTHEAST AT 20 MILES AN HOUR.

WPM
Special weather statement, Jul 17, 10:38 AM CDT, 3 hours 22 minutes before
IAZALL-171640-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1038 AM CDT SAT JUL 17 1993

AT 1025 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS...PRODUCING
EXTREMELY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLE SMALL HAIL...
CONTINUED OVER PARTS OF NORTHEAST INTO EAST CENTRAL IOWA.  THESE
STORMS WERE LOCATED IN A 25 MILE WIDE AREA...CENTERED FROM 15 MILES
SOUTHEAST OF WATERLOO...TO 5 MILES SOUTHEAST OF CEDAR RAPIDS.

THE THUNDERSTORMS WERE PART OF AN AREA OF SHOWERS AND STORMS COVERING
MUCH OF THE NORTH HALF OF IOWA.  THE STORMS AND SHOWERS WERE LOCATED
GENERALLY NORTH OF A LINE FROM 25 MILES NORTH OF COUNCIL BLUFFS/OMAHA
...TO 50 MILES NORTH OF DES MOINES...NEAR JEWELL..TO 50 MILES EAST OF
DES MOINES...NEAR GRINNEL...TO DAVENPORT/MOLINE.

THE STORMS AND SHOWERS WERE MOVING NORTHEAST AT 20 MILES AN HOUR.

WPM
Special weather statement, Jul 17, 11:37 AM CDT, 2 hours 23 minutes before
IAZALL-171740-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1137 AM CDT SAT JUL 17 1993

AT 1126 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS...PRODUCING
EXTREMELY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLE SMALL HAIL...
CONTINUED OVER PARTS OF NORTHEAST INTO EAST CENTRAL IOWA.  THESE
STORMS WERE LOCATED IN A 40 MILE WIDE AREA...CENTERED FROM 15 MILES
EAST OF WATERLOO...TO 10 MILES EAST OF CEDAR RAPIDS.

THE THUNDERSTORMS WERE PART OF AN AREA OF SHOWERS AND STORMS COVERING
MUCH OF THE NORTH HALF OF IOWA.  THE STORMS AND SHOWERS WERE LOCATED
GENERALLY NORTH OF A LINE FROM 25 MILES NORTH OF COUNCIL BLUFFS/OMAHA
...TO 70 MILES NORTH OF DES MOINES...NEAR IOWA FALLS...TO 25 MILES
WEST OF CEDAR RAPIDS...TO DAVENPORT/MOLINE.

THE STORMS AND SHOWERS WERE MOVING EAST AT 20 MILES AN HOUR.

WPM
Special weather statement, Jul 17, 11:38 AM CDT, 2 hours 22 minutes before
IAZALL-171740-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1137 AM CDT SAT JUL 17 1993

AT 1126 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS...PRODUCING
EXTREMELY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLE SMALL HAIL...
CONTINUED OVER PARTS OF NORTHEAST INTO EAST CENTRAL IOWA.  THESE
STORMS WERE LOCATED IN A 40 MILE WIDE AREA...CENTERED FROM 15 MILES
EAST OF WATERLOO...TO 10 MILES EAST OF CEDAR RAPIDS.

THE THUNDERSTORMS WERE PART OF AN AREA OF SHOWERS AND STORMS COVERING
MUCH OF THE NORTH HALF OF IOWA.  THE STORMS AND SHOWERS WERE LOCATED
GENERALLY NORTH OF A LINE FROM 25 MILES NORTH OF COUNCIL BLUFFS/OMAHA
...TO 70 MILES NORTH OF DES MOINES...NEAR IOWA FALLS...TO 25 MILES
WEST OF CEDAR RAPIDS...TO DAVENPORT/MOLINE.

THE STORMS AND SHOWERS WERE MOVING EAST AT 20 MILES AN HOUR.

WPM
Special weather statement, Jul 17, 11:44 AM CDT, 2 hours 16 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-171845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
1144 AM CDT SAT JUL 17 1993

...THE URBAN AND SMALL STREAM FLOOD ADVISORY HAS BEEN CANCELLED...

AT 1140 AM...THE ROADS THAT REPORTED TO BE FLOODING IN NORTH CENTRAL AND
NORTHEAST IOWA ARE NO LONGER FLOODING.  RAIN HAS ENDED OR BECOME LIGHT
OVER PORTIONS OF NORTH CENTRAL IOWA THAT WERE FLOODING.

PERSONS LIVING IN NORTHEAST AND NORTH CENTRAL IOWA SHOULD STILL BE
MONITORING THE WEATHER SITUATION AS THUNDERSTORMS WITH HEAVY RAIN ARE
EXPECTED TO REDEVELOP AGAIN THIS AFTERNOON.

WITH THE POTENTIAL FOR HEAVY RAINS AGAIN THIS AFTERNOON ON ALREADY
SATURATED GROUNDS...FLASH FLOODING MAY AGAIN OCCUR.  PLEASE STAY TUNED
TO YOUR LOCAL MEDIA OR NOAA WEATHER RADIO FOR LATER UPDATES AND POSSIBLE
WARNINGS.

LINDENBERG
Special weather statement, Jul 17, 11:44 AM CDT, 2 hours 16 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-171845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
1144 AM CDT SAT JUL 17 1993

...THE URBAN AND SMALL STREAM FLOOD ADVISORY HAS BEEN CANCELLED...

AT 1140 AM...THE ROADS THAT REPORTED TO BE FLOODING IN NORTH CENTRAL AND
NORTHEAST IOWA ARE NO LONGER FLOODING.  RAIN HAS ENDED OR BECOME LIGHT
OVER PORTIONS OF NORTH CENTRAL IOWA THAT WERE FLOODING.

PERSONS LIVING IN NORTHEAST AND NORTH CENTRAL IOWA SHOULD STILL BE
MONITORING THE WEATHER SITUATION AS THUNDERSTORMS WITH HEAVY RAIN ARE
EXPECTED TO REDEVELOP AGAIN THIS AFTERNOON.

WITH THE POTENTIAL FOR HEAVY RAINS AGAIN THIS AFTERNOON ON ALREADY
SATURATED GROUNDS...FLASH FLOODING MAY AGAIN OCCUR.  PLEASE STAY TUNED
TO YOUR LOCAL MEDIA OR NOAA WEATHER RADIO FOR LATER UPDATES AND POSSIBLE
WARNINGS.

LINDENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 5:44 AM CDTFlash Flood WarningDMXStory3 hr
Jul 17, 6:35 AM CDTFlash Flood WarningDMXHardin, Marshall3 hr
Jul 17, 9:20 AM CDTFlash Flood WarningDMXPolk3 hr
Jul 17, 3:42 PM CDTSevere Thunderstorm WarningDMXBenton33 min
Jul 17, 5:00 PM CDTSevere Thunderstorm WarningDMXLinn30 min
Jul 17, 6:03 PM CDTFlash Flood WarningDMXBuchanan3 hr

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.