Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 67, NWS Des Moines, IA

July 11, 1993Polk County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 11, 1993, 6:10 AM CDT for Polk County, Iowa. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jul 11, 1993, 6:10 AM CDT (11:10 UTC)
Expired
Jul 11, 1993, 10:15 AM CDT
In force
4 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Polk County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 11.2 hours before the alert went out and 236 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 1993-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3233 joules per kilogram.LCLEL10008507005003002001001 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 1993-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 square meters per square second.19395878Sfc1 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
3233 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
992 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
1.1
Supercell composite
6.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 111110
FFWDSM
IAC153-111515-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
610 AM CDT SUN JUL 11 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1015 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION(S)...
 
IN CENTRAL IOWA
 
   ...SOUTHERN POLK COUNTY
 
AT 6 AM...FOUR MILE CREEK IN DES MOINES WAS RISING RAPIDLY. FLOODING
VERY SIMILAR TO TWO DAYS AGO WILL OCCUR AGAIN THIS MORNING. PERSONS
AFFECTED BY FLOODING ALONG FOUR MILE CREEK SHOULD MOVE TO HIGHER GROUND
NOW.
 
FLOOD STAGE AT THE EASTON BRIDGE IS 12 FEET AND THE CREEK WAS PASSING
THROUGH THAT HEIGHT.  AN ESTIMATED CREST AROUND 15 FEET IS EXPECTED
AROUND 8 AM THIS MORNING.
 
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.
 
MYERS

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 11, 4:17 AM CDT, 1 hour 53 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-111015-

SPECIAL WEATHER STATEMENT...REVISED FOR WORDING...
NATIONAL WEATHER SERVICE WATERLOO IA
410 AM CDT SUN JUL 11 1993

...HEAVY RAINS MAY CAUSE SOME STREET FLOODING SOUTH OF WATERLOO...

THUNDERSTORMS WITH HEAVY RAINS WERE RUMBLING FROM 5 MILES SOUTHWEST OF
TO 15 MILES SOUTHEAST OF WATERLOO. THESE STORMS ARE LIKELY PRODUCING
FREQUENT DEADLY LIGHTNING...GUSTY WINDS OF 30 TO 40 MPH AND SMALL HAIL
IN ADDITION TO THE HEAVY RAINS. OTHER STORMS WERE REFIRING ALONG I-35
FROM MASON CITY TO HAMPTON...HAMPTON IS 25 MILES SOUTH OF MASON CITY.

THROUGH 5 AM THE STRONGEST STORMS ARE GOING TO AFFECT LAPORTE CITY...
GILBERTVILLE...JESUP...INDEPENDENCE...ROWLEY AND WALKER WHILE OTHER
LESS INTENSE STORMS AFFECT THE REST OF NORTHEAST IOWA.

HEAVY RAINS MAY CONTRIBUTE TO SOME URBAN AND SMALL STREAM FLOODING
SO MOTORISTS ARE ADVISED TO STAY ALERT FOR WATER-COVERED ROADS...
ESPECIALLY IN THE AFOREMENTIONED COMMUNITIES.

COLLAR
Special weather statement, Jul 11, 4:38 AM CDT, 1 hour 32 minutes before
IAZALL-110940-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
438 AM CDT SUN JUL 11 1993

...A FLASH FLOOD WATCH IS IN EFFECT FOR IOWA FOR TONIGHT...

AT 427 AM CDT...A 15 MILE WIDE BAND OF STRONG THUNDERSTORMS WAS OVER
CENTRAL IOWA.  THE STORMS WERE CENTERED FROM 25 MILES EAST OF DES MOINES
...NEAR NEWTON TO 30 MILES SOUTH OF DES MOINES...NEAR LUCAS.  THESE
STORMS HAVE BEEN PRODUCING VERY HEAVY RAINS...GUSTY WINDS UP TO 40 MILES
AN HOUR...FREQUENT DEADLY LIGHTNING AND POSSIBLY SMALL HAIL.

THE STORMS WERE PART OF A LARGE AREA OF SCATTERED SHOWERS AND STORMS
OCCURRING OVER THE EAST TWO THIRDS OF THE STATE.  THE AREA OF SHOWERS
AND STORMS WAS EAST OF A LINE FROM 35 MILES WEST OF MASON CITY TO 40
MILES WEST OF DES MOINES TO 30 MILES WEST OF LAMONI.

THE SHOWERS AND STORMS WERE MOVING EAST AT AROUND 35 MILES AN HOUR.

FILLBACH
Special weather statement, Jul 11, 4:42 AM CDT, 1 hour 28 minutes before
IAZALL-110940-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
438 AM CDT SUN JUL 11 1993

...A FLASH FLOOD WATCH IS IN EFFECT FOR IOWA FOR TONIGHT...

AT 427 AM CDT...A 15 MILE WIDE BAND OF STRONG THUNDERSTORMS WAS OVER
CENTRAL IOWA.  THE STORMS WERE CENTERED FROM 25 MILES EAST OF DES MOINES
...NEAR NEWTON TO 30 MILES SOUTH OF DES MOINES...NEAR LUCAS.  THESE
STORMS HAVE BEEN PRODUCING VERY HEAVY RAINS...GUSTY WINDS UP TO 40 MILES
AN HOUR...FREQUENT DEADLY LIGHTNING AND POSSIBLY SMALL HAIL.

THE STORMS WERE PART OF A LARGE AREA OF SCATTERED SHOWERS AND STORMS
OCCURRING OVER THE EAST TWO THIRDS OF THE STATE.  THE AREA OF SHOWERS
AND STORMS WAS EAST OF A LI$NE FROM 35 MILES WEST OF MASON CITY TO 40
MILES WEST OF DES MOINES TO 30 MILES WEST OF LAMONI.

THE SHOWERS AND STORMS WERE MOVING EAST AT AROUND 35 MILES AN HOUR.

FILLBACH
Special weather statement, Jul 11, 5:10 AM CDT, 1 hour before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-111115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
510 AM CDT SUN JUL 11 1993

...THE RAINS TO END IN SOME AREAS BUT CONTINUE FOR MOST OF US...

A LARGE AREA OF SHOWERS AND THUNDERSTORMS IS GOING TO PERSIST THROUGH
7 AM FOR MOST LOCATIONS BUT COME TO AN END IN THE I-35 AREA. THE
STRONGEST STORMS WILL MOVE OUT OF THE WATERLOO/CEDAR FALLS AREA BY 530
AND AFFECT INDEPENDENCE...ANAMOSA AND MONTICELLO THROUGH 7 AM.

WITH THE GROUND ALREADY SATURATED THE RAIN MAY RUNOFF CAUSING SOME
URBAN AND SMALL STREAM FLOODING. IF YOU ENCOUNTER A ROADWAY WITH
STANDING WATER DO NOT ATTEMPT TO DRIVE THROUGH IT.

COLLAR
ESPECIALLY IN THE AFOREMENTIONED COMMUNITIES.

COLLAR
Special weather statement, Jul 11, 5:11 AM CDT, 59 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-111115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
510 AM CDT SUN JUL 11 1993

...THE RAINS TO END IN SOME AREAS BUT CONTINUE FOR MOST OF US...

A LARGE AREA OF SHOWERS AND THUNDERSTORMS IS GOING TO PERSIST THROUGH
7 AM FOR MOST LOCATIONS BUT COME TO AN END IN THE I-35 AREA. THE
STRONGEST STORMS WILL MOVE OUT OF THE WATERLOO/CEDAR FALLS AREA BY 530
AND AFFECT INDEPENDENCE...ANAMOSA AND MONTICELLO THROUGH 7 AM.

WITH THE GROUND ALREADY SATURATED THE RAIN MAY RUNOFF CAUSING SOME
URBAN AND SMALL STREAM FLOODING. IF YOU ENCOUNTER A ROADWAY WITH
STANDING WATER DO NOT ATTEMPT TO DRIVE THROUGH IT.

COLLAR
ESPECIALLY IN THE AFOREMENTIONED COMMUNITIES.

COLLAR
Special weather statement, Jul 11, 5:12 AM CDT, 58 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-111115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
510 AM CDT SUN JUL 11 1993

...THE RAINS TO END IN SOME AREAS BUT CONTINUE FOR MOST OF US...

A LARGE AREA OF SHOWERS AND THUNDERSTORMS IS GOING TO PERSIST THROUGH
7 AM FOR MOST LOCATIONS BUT COME TO AN END IN THE I-35 AREA. THE
STRONGEST STORMS WILL MOVE OUT OF THE WATERLOO/CEDAR FALLS AREA BY 530
AND AFFECT INDEPENDENCE...ANAMOSA AND MONTICELLO THROUGH 7 AM.

WITH THE GROUND ALREADY SATURATED THE RAIN MAY RUNOFF CAUSING SOME
URBAN AND SMALL STREAM FLOODING. IF YOU ENCOUNTER A ROADWAY WITH
STANDING WATER DO NOT ATTEMPT TO DRIVE THROUGH IT.

COLLAR

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 7:25 PM CDTSevere Thunderstorm WarningDMXMitchell37 min
Jul 10, 8:39 PM CDTFlash Flood WarningDMXAppanoose2 hr
Jul 10, 8:39 PM CDTFlash Flood WarningDMXWayne102 min
Jul 10, 11:05 PM CDTSevere Thunderstorm WarningDMXLucas19 min
Jul 10, 11:36 PM CDTFlash Flood WarningDMXDickinson, Emmet3 hr
Jul 10, 11:56 PM CDTFlash Flood WarningDMXClay, Palo Alto3 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.