Alert archive / Iowa / Tornado Warnings in 1993

Tornado Warning 22, NWS Des Moines, IA

July 8, 1993Boone County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 8, 1993, 9:09 PM CDT for Boone County, Iowa. It was in force for 36 min.

The area

The counties it named.

The facts

Issued
Jul 8, 1993, 9:09 PM CDT (02:09 UTC)
Expired
Jul 8, 1993, 9:45 PM CDT
In force
36 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Boone County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.2 hours before the alert went out and 218 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 1993-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3257 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 1993-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 244 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
3257 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
692 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
244 m²/s²
0-3 km storm-relative helicity
341 m²/s²
Significant tornado parameter
6.3
Supercell composite
27.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 090210
TORDSM
IAC015-090245-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
909 PM CDT THU JUL 8 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  945 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION(S)...
 
IN CENTRAL IOWA
 
   ...SOUTHERN BOONE COUNTY
 
AT 904 PM CDT...RADAR INDICATED A TORNADO 10 MILES SOUTHWEST OF BOONE.
BOONE IS ABOUT 15 MILES WEST OF AMES. PEOPLE IN LIVING IN LUTHER AND
RURAL AREAS OF SOUTHERN BOONE COUNTY SHOULD TAKE COVER NOW!
 
R A PRENTICE
 
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND MOBILE HOMES
FOR A REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.

What forecasters said that day

The local office's own words before this tornado 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 8, 8:05 PM CDT, 1 hour 4 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-090215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
805 PM CDT THU JUL 8 1993

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL MIDNIGHT...

AT 800 PM...STRONG THUNDERSTORMS WERE CONTINUING ACROSS PORTIONS OF
NORTHEAST AND NORTH CENTRAL IOWA.  THESE THUNDERSTORMS WERE PRODUCING
VERY HEAVY RAINS...DEADLY LIGHTNING...STRONG GUSTY WINDS...AND POSSIBLE
SMALL HAIL.  THESE THUNDERSTORMS WERE IN A LINE THAT EXTENDED FROM 25
MILES SOUTH OF MASON CITY...TO DUMONT...TO WAVERLY...TO WEST UNION.
MOVEMENT WAS TO THE NORTHEAST AT 35 MILES AN HOUR AND WILL BE AFFECTING
THE TOWNS OF SHEFFIELD...MARBLE ROCK...CLARKSVILLE...WAVERLY...
WEST UNION...AND CHARLES CITY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT FOR NORTH
CENTRAL AND PORTIONS OF NORTHEAST IOWA.  ATMOSPHERIC CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS TO DEVELOP WITHIN THIS WATCH AREA.
PERSONS WITHIN THE WATCH AREA SHOULD REMAIN ALERT FOR ANY CHANGES
IN THE WEATHER AND BE PREPARED TO TAKE ACTION IF A WARNING IS ISSUED.
STAY TUNED TO YOUR TELEVISION...RADIO...OR NOAA WEATHER RADIO FOR
FURTHER UPDATES AND POSSIBLE WARNINGS.

LINDENBERG
Special weather statement, Jul 8, 8:07 PM CDT, 1 hour 2 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-090215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
805 PM CDT THU JUL 8 1993

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL MIDNIGHT...

AT 800 PM...STRONG THUNDERSTORMS WERE CONTINUING ACROSS PORTIONS OF
NORTHEAST AND NORTH CENTRAL IOWA.  THESE THUNDERSTORMS WERE PRODUCING
VERY HEAVY RAINS...DEADLY LIGHTNING...STRONG GUSTY WINDS...AND POSSIBLE
SMALL HAIL.  THESE THUNDERSTORMS WERE IN A LINE THAT EXTENDED FROM 25
MILES SOUTH OF MASON CITY...TO DUMONT...TO WAVERLY...TO WEST UNION.
MOVEMENT WAS TO THE NORTHEAST AT 35 MILES AN HOUR AND WILL BE AFFECTING
THE TOWNS OF SHEFFIELD...MARBLE ROCK...CLARKSVILLE...WAVERLY...
WEST UNION...AND CHARLES CITY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT FOR NORTH
CENTRAL AND PORTIONS OF NORTHEAST IOWA.  ATMOSPHERIC CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS TO DEVELOP WITHIN THIS WATCH AREA.
PERSONS WITHIN THE WATCH AREA SHOULD REMAIN ALERT FOR ANY CHANGES
IN THE WEATHER AND BE PREPARED TO TAKE ACTION IF A WARNING IS ISSUED.
STAY TUNED TO YOUR TELEVISION...RADIO...OR NOAA WEATHER RADIO FOR
FURTHER UPDATES AND POSSIBLE WARNINGS.

LINDENBERG
Special weather statement, Jul 8, 8:50 PM CDT, 19 minutes before
IAZALL-090245-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
850 PM CDT THU JUL 8 1993

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR NORTH CENTRAL AND
   WESTERN IOWA UNTIL MIDNIGHT...

AT 840 PM CDT...A LINE OF VERY STRONG THUNDERSTORMS CONTINUED FROM WEST
CENTRAL INTO NORTH CENTRAL AND NORTHEAST IOWA.  THE STORMS WERE LOCATED
IN A 20 MILE WIDE BAND EXTENDING FROM 40 MILES NORTHEAST OF COUNCIL
BLUFFS...TO 40 MILES NORTHWEST OF DES MOINES NEAR JEFFERSON...TO FORT
DODGE...TO 15 MILES NORTH OF WATERLOO NEAR SUMNER.  THESE STORMS WERE
PRODUCING TORRENTIAL RAINFALL...GUSTY WINDS AND HAIL.

THE THUNDERSTORMS WERE PART OF AN AREA OF SCATTERED SHOWERS AND STORMS
THAT WERE OCCURRING NORTH OF A LINE FROM COUNCIL BLUFFS TO 50 MILES
NORTHEAST OF WATERLOO NEAR ELKADER.

THE STORMS AND SHOWERS WERE MOVING EAST AT 30 MILES AN HOUR.

/
KALLMAN
Special weather statement, Jul 8, 8:50 PM CDT, 19 minutes before
IAZALL-090245-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
850 PM CDT THU JUL 8 1993

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR NORTH CENTRAL AND
   WESTERN IOWA UNTIL MIDNIGHT...

AT 840 PM CDT...A LINE OF VERY STRONG THUNDERSTORMS CONTINUED FROM WEST
CENTRAL INTO NORTH CENTRAL AND NORTHEAST IOWA.  THE STORMS WERE LOCATED
IN A 20 MILE WIDE BAND EXTENDING FROM 40 MILES NORTHEAST OF COUNCIL
BLUFFS...TO 40 MILES NORTHWEST OF DES MOINES NEAR JEFFERSON...TO FORT
DODGE...TO 15 MILES NORTH OF WATERLOO NEAR SUMNER.  THESE STORMS WERE
PRODUCING TORRENTIAL RAINFALL...GUSTY WINDS AND HAIL.

THE THUNDERSTORMS WERE PART OF AN AREA OF SCATTERED SHOWERS AND STORMS
THAT WERE OCCURRING NORTH OF A LINE FROM COUNCIL BLUFFS TO 50 MILES
NORTHEAST OF WATERLOO NEAR ELKADER.

THE STORMS AND SHOWERS WERE MOVING EAST AT 30 MILES AN HOUR.

/
KALLMAN
Special weather statement, Jul 8, 9:05 PM CDT, 4 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-090315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
905 PM CDT THU JUL 8 1993

...THUNDERSTORMS CONTINUE TO DUMP HEAVY RAIN ACROSS NORTH CENTRAL
AND NORTHEAST IOWA...

AT 900 PM...STRONG THUNDERSTORMS WERE PRODUCING VERY HEAVY RAINS ALONG
WITH WINDS NEAR 45 MILES AN HOUR.  THESE THUNDERSTORMS WERE LOCATED
FROM AROUND HAMPTON TO MARBLE ROCK AND SUMNER...ABOUT 35 MILES WEST OF
WATERLOO AND 25 MILES NORTH.  THIS RAIN COULD CAUSE SOME SMALL STREAMS
AND POSSIBLE LOW LAND FLOODING IN THE CEDAR AND WAPSIPINICON RIVER
BASIN.

TOWNS EFFECTED BY THESE THUNDERSTORMS BETWEEN 910 PM AND 10 PM WILL BE
NEW HAMPTON...NASHUA...FREDERICKSBURG AND ALPHA AS THEY MOVE NORTHEAST
AT 25 MILES AN HOUR.
THIS RAIN SITUATION SHOULD BE WATCHED CLOSELY.  THE GROUND IS
SATURATED AND STREAMS ARE ALREADY HIGHER THAN NORMAL.  IF DRIVING
TONIGHT DO NOT CROSS FLOODED ROADWAYS AND BE PREPARED TO MOVE TO
HIGHER GROUND IF FLOODING STARTS TO OCCUR.  STAY TUNED TO RADIO
...NOAA WEATHER RADIO AND TV FOR LATER WEATHER STATEMENTS AS A
SEVERE THUNDERSTORM WATCH REMAIN IN EFFECT UNTIL MIDNIGHT FOR
MUCH OF NORTH CENTRAL AND NORTHEAST IOWA ALONG AND WEST OF HIGHWAY
63.

RR
Special weather statement, Jul 8, 9:08 PM CDT, 1 minute before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-090315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
905 PM CDT THU JUL 8 1993

...THUNDERSTORMS CONTINUE TO DUMP HEAVY RAIN ACROSS NORTH CENTRAL
AND NORTHEAST IOWA...

AT 900 PM...STRONG THUNDERSTORMS WERE PRODUCING VERY HEAVY RAINS ALONG
WITH WINDS NEAR 45 MILES AN HOUR.  THESE THUNDERSTORMS WERE LOCATED
FROM AROUND HAMPTON TO MARBLE ROCK AND SUMNER...ABOUT 35 MILES WEST OF
WATERLOO AND 25 MILES NORTH.  THIS RAIN COULD CAUSE SOME SMALL STREAMS
AND POSSIBLE LOW LAND FLOODING IN THE CEDAR AND WAPSIPINICON RIVER
BASIN.

TOWNS EFFECTED BY THESE THUNDERSTORMS BETWEEN 910 PM AND 10 PM WILL BE
NEW HAMPTON...NASHUA...FREDERICKSBURG AND ALPHA AS THEY MOVE NORTHEAST
AT 25 MILES AN HOUR.
THIS RAIN SITUATION SHOULD BE WATCHED CLOSELY.  THE GROUND IS
SATURATED AND STREAMS ARE ALREADY HIGHER THAN NORMAL.  IF DRIVING
TONIGHT DO NOT CROSS FLOODED ROADWAYS AND BE PREPARED TO MOVE TO
HIGHER GROUND IF FLOODING STARTS TO OCCUR.  STAY TUNED TO RADIO
...NOAA WEATHER RADIO AND TV FOR LATER WEATHER STATEMENTS AS A
SEVERE THUNDERSTORM WATCH REMAIN IN EFFECT UNTIL MIDNIGHT FOR
MUCH OF NORTH CENTRAL AND NORTHEAST IOWA ALONG AND WEST OF HIGHWAY
63.

RR

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 7:12 PM CDTSevere Thunderstorm WarningDMXCrawford43 min
Jul 8, 7:12 PM CDTSevere Thunderstorm WarningDMXCarroll48 min
Jul 8, 8:05 PM CDTSevere Thunderstorm WarningDMXCarroll, Greene, Guthrie55 min
Jul 8, 8:27 PM CDTFlash Flood WarningDMXCarroll, Crawford, Greene4 hr
Jul 8, 8:57 PM CDTTornado WarningDMXCarroll, Crawford19 min
Jul 8, 9:29 PM CDTFlash Flood WarningDMXBoone, Story4 hr
Jul 8, 9:29 PM CDTFlash Flood WarningDMXDallas, Guthrie4 hr
Jul 8, 9:31 PM CDTTornado WarningDMXChickasaw29 min
Jul 8, 9:52 PM CDTTornado WarningDMXBoone, Dallas38 min
Jul 8, 10:03 PM CDTTornado WarningDMXDallas, Polk27 min
Jul 8, 10:47 PM CDTFlash Flood WarningDMXBlack Hawk3 hr
Jul 8, 10:52 PM CDTSevere Thunderstorm WarningDMXBuchanan20 min
Jul 8, 11:25 PM CDTFlash Flood WarningDMXJasper, Polk5 hr
Jul 8, 11:25 PM CDTFlash Flood WarningDMXMarshall5 hr
Jul 8, 11:40 PM CDTSevere Thunderstorm WarningDMXAudubon, Carroll, Crawford35 min
Jul 8, 11:40 PM CDTSevere Thunderstorm WarningDMXAdams, Cass, Taylor35 min
Jul 8, 11:49 PM CDTFlash Flood WarningDMXBuchanan3 hr
Jul 9, 12:02 AM CDTSevere Thunderstorm WarningDMXAdair, Ringgold, Union28 min
Jul 9, 12:02 AM CDTSevere Thunderstorm WarningDMXGreene, Guthrie28 min
Jul 9, 12:22 AM CDTFlash Flood WarningDMXCarroll, Greene4 hr
Jul 9, 12:22 AM CDTFlash Flood WarningDMXAudubon4 hr
Jul 9, 12:33 AM CDTSevere Thunderstorm WarningDMXDallas, Madison, Polk, Warren27 min
Jul 9, 12:33 AM CDTSevere Thunderstorm WarningDMXClarke, Decatur27 min
Jul 9, 1:01 AM CDTFlash Flood WarningDMXBlack Hawk119 min
Jul 9, 1:05 AM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Wayne25 min
Jul 9, 1:05 AM CDTSevere Thunderstorm WarningDMXJasper, Marion, Polk25 min
Jul 9, 1:05 AM CDTSevere Thunderstorm WarningDMXWarren25 min
Jul 9, 1:22 AM CDTSevere Thunderstorm WarningDMXBlack Hawk23 min
Jul 9, 1:36 AM CDTSevere Thunderstorm WarningDMXMahaska, Poweshiek54 min
Jul 9, 1:36 AM CDTSevere Thunderstorm WarningDMXAppanoose, Davis, Monroe, Wapello54 min
Jul 9, 1:36 AM CDTSevere Thunderstorm WarningDMXJasper49 min
Jul 9, 2:11 AM CDTSevere Thunderstorm WarningDMXJefferson, Keokuk, Van Buren, Washington49 min
Jul 9, 2:11 AM CDTSevere Thunderstorm WarningDMXIowa, Johnson49 min
Jul 9, 10:21 AM CDTFlash Flood WarningDMXStory6 hr

Nearby

Tornado Warnings in Iowa, 1993Every tornado warning in 1993Tornadoes 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.