Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 70, NWS Des Moines, IA

July 13, 1993Polk County, Story County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 13, 1993, 8:14 AM CDT for Polk County, Story County, Iowa. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jul 13, 1993, 8:14 AM CDT (13:14 UTC)
Expired
Jul 13, 1993, 12:00 PM CDT
In force
4 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Polk County, IA, Story County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 1.2 hours before the alert went out and 332 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, Minneapolis, MN at 12:00Z on 1993-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 1993-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 square meters per square second.19395878Sfc1 km3 km6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 131315
FFWDSM
IAC153-169-131700-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
814 AM CDT TUE JUL 13 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL NOON  CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL IOWA
 
   ...POLK COUNTY...STORY COUNTY
 
AT 810 AM CDT...NATIONAL WEATHER SERVICE RADAR SHOWED VERY HEAVY RAIN
OVER AMES IN STORY COUNTY...EXTENDING SOUTH THROUGH THE DES MOINES METRO
AREA...THEN SOUTHWEST TO NEAR CRESTON.
 
THESE STORMS WERE DUMPING OVER AN INCH OF RAIN IN ABOUT A HALF
HOUR...AND WILL CONTINUE TO DO SO OVER THE SKUNK RIVER...SQUAW
CREEK...WALNUT CREEK...AND FOUR MILE CREEK BASINS IN STORY AND POLK
COUNTIES.  IF YOU ARE NEAR ANY OF THESE CREEKS OR RIVERS...YOU SHOULD
MOVE ..IMMEDIATELY.. TO HIGHER GROUND!
 
MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IFN WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A
SMALL ONE...ON FOOT.
 
SULLIVAN
 
&

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 13, 6:45 AM CDT, 1 hour 29 minutes before
IAZALL-131240-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
643 AM CDT TUE JUL 13 1993

...A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF IOWA TODAY AND TONIGHT...

AT 632 AM CDT...NUMEROUS SHOWERS AND THUNDERSTORMS...MANY WITH VERY
HEAVY RAIN...CONTINUED ACROSS THE NORTHWEST HALF OF IOWA.

THIS RAIN AREA WAS LOCATED NORTHWEST OF A LINE EXTENDING FROM THE
MINNESOTA BORDER 60 MILES NORTH OF WATERLOO...TO 30 MILES NORTH OF
WATERLOO...TO DES MOINES...TO THE MISSOURI BORDER 50 MILES WEST OF
LAMONI AT BRADDYVILLE. THE HEAVIEST RAINS WERE FALLING ACROSS SOUTHWEST
IOWA.

MOVEMENT WAS NORTHEAST AT 40 MILES AN HOUR.

R A PRENTICE
Special weather statement, Jul 13, 7:14 AM CDT, 1 hour before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-131315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
715 AM CDT TUE JUL 13 1993

...STRONG STORMS TAKING AN AIM ON NORTH CENTRAL IOWA...

A FLASH FLOOD WATCH IS IN EFFECT TODAY AND TONIGHT FOR THE ENTIRE
STATE. THUNDERSTORMS WITH HEAVY RAINS IN CENTRAL IOWA ARE EXPECTED TO
MASON CITY...NORTHWOOD AND FOREST CITY AREAS OF NORTH CENTRAL IOWA.
MOVE INTO THE ACKLEY AND HAMPTON AREAS AROUND 8 AM AND INTO THE
PARKERSBURG...CLARKSVILLE AND MARBLE ROCK AREAS BETWEEN 8 AND 9 AM.

AT THIS TIME IT APPEARS THE HEAVIEST RAINS FROM THESE STORMS SHOULD
STAY WEST AND NORTHWEST OF THE WATERLOO/CEDAR FALLS AREA...HOWEVER
THOSE LIVING IN NORTH CENTRAL IOWA BETWEEN I-35 AND HIGHWAY 218 SHOULD
BE PREPARED TO ACT QUICKLY SHOULD WATERS RISE AND FLASH FLOODING OCCUR.
THIS IS A DANGEROUS SITUATION AND PEOPLE ARE URGED TO MONITOR TV...
NOAA WEATHER RADIO OR COMMERCIAL RADIO FOR UPDATES ON FLOODING.

COLLAR
Special weather statement, Jul 13, 7:15 AM CDT, 59 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-131315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
715 AM CDT TUE JUL 13 1993

...STRONG STORMS TAKING AN AIM ON NORTH CENTRAL IOWA...

A FLASH FLOOD WATCH IS IN EFFECT TODAY AND TONIGHT FOR THE ENTIRE
STATE. THUNDERSTORMS WITH HEAVY RAINS IN CENTRAL IOWA ARE EXPECTED TO
MASON CITY...NORTHWOOD AND FOREST CITY AREAS OF NORTH CENTRAL IOWA.
MOVE INTO THE ACKLEY AND HAMPTON AREAS AROUND 8 AM AND INTO THE
PARKERSBURG...CLARKSVILLE AND MARBLE ROCK AREAS BETWEEN 8 AND 9 AM.

AT THIS TIME IT APPEARS THE HEAVIEST RAINS FROM THESE STORMS SHOULD
STAY WEST AND NORTHWEST OF THE WATERLOO/CEDAR FALLS AREA...HOWEVER
THOSE LIVING IN NORTH CENTRAL IOWA BETWEEN I-35 AND HIGHWAY 218 SHOULD
BE PREPARED TO ACT QUICKLY SHOULD WATERS RISE AND FLASH FLOODING OCCUR.
THIS IS A DANGEROUS SITUATION AND PEOPLE ARE URGED TO MONITOR TV...
NOAA WEATHER RADIO OR COMMERCIAL RADIO FOR UPDATES ON FLOODING.

COLLAR
Special weather statement, Jul 13, 7:16 AM CDT, 58 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-131315-

SPECIAL WEATHER STATEMENT...DELETED EXTRA LINE...
NATIONAL WEATHER SERVICE WATERLOO IA
715 AM CDT TUE JUL 13 1993

...STRONG STORMS TAKING AN AIM ON NORTH CENTRAL IOWA...

A FLASH FLOOD WATCH IS IN EFFECT TODAY AND TONIGHT FOR THE ENTIRE
STATE. THUNDERSTORMS WITH HEAVY RAINS IN CENTRAL IOWA ARE EXPECTED TO
MOVE INTO THE ACKLEY AND HAMPTON AREAS AROUND 8 AM AND INTO THE
PARKERSBURG...CLARKSVILLE AND MARBLE ROCK AREAS BETWEEN 8 AND 9 AM.

AT THIS TIME IT APPEARS THE HEAVIEST RAINS FROM THESE STORMS SHOULD
STAY WEST AND NORTHWEST OF THE WATERLOO/CEDAR FALLS AREA...HOWEVER
THOSE LIVING IN NORTH CENTRAL IOWA BETWEEN I-35 AND HIGHWAY 218 SHOULD
BE PREPARED TO ACT QUICKLY SHOULD WATERS RISE AND FLASH FLOODING OCCUR.
THIS IS A DANGEROUS SITUATION AND PEOPLE ARE URGED TO MONITOR TV...
NOAA WEATHER RADIO OR COMMERCIAL RADIO FOR UPDATES ON FLOODING.

COLLAR
Special weather statement, Jul 13, 7:46 AM CDT, 28 minutes before
IAZALL-131340-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
746 AM CDT TUE JUL 13 1993

...A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF IOWA TODAY AND TONIGHT...

AT 735 AM CDT...A 15 MILE WIDE AREA OF VERY STRONG THUNDERSTORMS WAS
LOCATED FROM SOUTHWEST INTO CENTRAL IOWA. THE STORMS WERE LOCATED FROM
5 MILES SOUTHWEST OF CRESTON OR ABOUT 50 MILES SOUTHWEST OF DES MOINES
NORTHEAST TO NEAR DALLAS CENTER OR ABOUT 15 MILES WEST OF DES MOINES.
THIS LINE OF STORMS CONTINUED FROM NEVADA NORTH TO NEAR JEWELL. NEVADA
30 MILES NORTH OF DES MOINES WHILE JEWELL IS ABOUT 45 MILES NORTH OF
DES MOINES. SEVERAL OF THE STORMS IN THIS AREA WILL PRODUCE VERY HEAVY
RAIN AND DEADLY LIGHTNING.

THESE STORMS WERE PART OF A MUCH LARGER AREA OF SHOWERS AND STORMS ALONG
AND WEST OF A LINE FROM MOUNT AYR NORTHEAST TO OELWEIN. MOUNT AYR IS 55
MILES SOUTHWEST OF DES MOINES WHILE OELWEIN IS 20 ABOUT 20 MILES EAST OF
WATERLOO.

THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 40 MILES AN HOUR.

BARLOW
Special weather statement, Jul 13, 7:51 AM CDT, 23 minutes before
IAZALL-131340-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
746 AM CDT TUE JUL 13 1993

...A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF IOWA TODAY AND TONIGHT...

AT 735 AM CDT...A 15 MILE WIDE AREA OF VERY STRONG THUNDERSTORMS WAS
LOCATED FROM SOUTHWEST INTO CENTRAL IOWA. THE STORMS WERE LOCATED FROM
5 MILES SOUTHWEST OF CRESTON OR ABOUT 50 MILES SOUTHWEST OF DES MOINES
NORTHEAST TO NEAR DALLAS CENTER OR ABOUT 15 MILES WEST OF DES MOINES.
THIS LINE OF STORMS CONTINUED FROM NEVADA NORTH TO NEAR JEWELL. NEVADA
30 MILES NORTH OF DES MOINES WHILE JEWELL IS ABOUT 45 MILES NORTH OF
DES MOINES. SEVERAL OF THE STORMS IN THIS AREA WILL PRODUCE VERY HEAVY
RAIN AND DEADLY LIGHTNING.

THESE STORMS WERE PART OF A MUCH LARGER AREA OF SHOWERS AND STORMS ALONG
AND WEST OF A LINE FROM MOUNT AYR NORTHEAST TO OELWEIN. MOUNT AYR IS 55
MILES SOUTHWEST OF DES MOINES WHILE OELWEIN IS 20 ABOUT 20 MILES EAST OF
WATERLOO.

THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 40 MILES AN HOUR.

BARLOW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 5:46 AM CDTFlash Flood WarningDMXDallas, Polk6 hr
Jul 13, 6:47 AM CDTFlash Flood WarningDMXCass3 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.