Alert archive / Iowa / Tornado Warnings in 1994

Tornado Warning 25, NWS Des Moines, IA

July 19, 1994Allamakee County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 1994, 10:27 PM CDT for Allamakee County, Iowa. It was in force for 37 min.

The area

The counties it named.

The facts

Issued
Jul 19, 1994, 10:27 PM CDT (03:27 UTC)
Expired
Jul 19, 1994, 11:04 PM CDT
In force
37 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Allamakee County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 3.5 hours before the alert went out and 249 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 00:00Z on 1994-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 503 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 00:00Z on 1994-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.193958Sfc1 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
503 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
682 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
343 m²/s²
Significant tornado parameter
0.8
Supercell composite
7.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KALO 200329
TORALO
IAC005-200415-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE WATERLOO IA
1027 PM CDT TUE JUL 19 1994
 
THE NATIONAL WEATHER SERVICE IN WATERLOO HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL 1115 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHEAST IOWA
 
   ...SOUTHERN ALLAMAKEE COUNTY
 
AT 1023 PM CDT...A STATE TROOPER REPORTED TORNADOES ON THE GROUND 1 MILE
NORTH AND 2 MILES WEST OF WAUKON. THESE TORNADOES WERE MOVING EAST
SOUTHEAST AT 25 MPH AND WILL AFFECT THE TOWNS OF WAUKON...ROSSVILLE AND
WATERVILLE THROUGH 1115 PM CDT.
 
DURING A TORNADO...THE SAFEST PLACE IS IN A BASEMENT.  GET UNDER
A WORKBENCH OR PIECE OF STURDY FURNITURE.  IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER IN AN INTERIOR ROOM SUCH AS A CLOSET ON
THE LOWEST FLOOR.  AVOID WINDOWS.
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  YOU SHOULD
SEEK SHELTER BELOW GROUND LEVEL IF POSSIBLE.  OTHERWISE...GO TO A
SMALL INTERIOR ROOM ON THE LOWEST FLOOR POSSIBLE AND AVOID WINDOWS.
 
&
 
TRS

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 19, 9:22 PM CDT, 1 hour 5 minutes before
IAZ071-200330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
922 PM CDT TUE JUL 19 1994

AT 920 PM CDT DOPPLER RADAR INDICATED THAT THUNDEDERSTORMS WERE BUILDING
RAPIDLY SOUTHWARD ALONG A COOL FRONT NOW PUSHING INTO CENTRAL IOWA. A
LINE OF THUNDERSTORMS WAS NOW LOCATED FROM NEAR DECORAH TO JUST WEST OF
AMES.

THUNDERSTORMS SHOULD CONTINUE TO BUILD SOUTH TO JUST NORTH OF DES MOINES
DURING THE NEXT HOUR.  LITTLE MOVEMENT WAS DETECTED ON THE SOUTH END OF
THE LINE.  TORRENTIAL RAIN AND FREQUENT DANGEROUS LIGHTNING ARE THE MAIN
BY-PRODUCTS OF THESE THUNDERSTORMS.

 BELLES
Special weather statement, Jul 19, 9:26 PM CDT, 1 hour 1 minute before
IAZ071-200330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
922 PM CDT TUE JUL 19 1994

AT 920 PM CDT DOPPLER RADAR INDICATED THAT THUNDEDERSTORMS WERE BUILDING
RAPIDLY SOUTHWARD ALONG A COOL FRONT NOW PUSHING INTO CENTRAL IOWA. A
LINE OF THUNDERSTORMS WAS NOW LOCATED FROM NEAR DECORAH TO JUST WEST OF
AMES.

THUNDERSTORMS SHOULD CONTINUE TO BUILD SOUTH TO JUST NORTH OF DES MOINES
DURING THE NEXT HOUR.  LITTLE MOVEMENT WAS DPETECTED ON THE SOUTH END OF
THE LINE.  TORRENTIAL RAIN AND FREQUENT DANGEROUS LIGHTNING ARE THE MAIN
BY-PRODUCTS OF THESE THUNDERSTORMS.

 BELLES
Special weather statement, Jul 19, 9:27 PM CDT, 1 hour before
IAZALL-200330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
922 PM CDT TUE JUL 19 1994

AT 920 PM CDT DOPPLER RADAR INDICATED THAT THUNDERSTORMS WERE BUILDING
RAPIDLY SOUTHWARD ALONG A COOL FRONT NOW PUSHING INTO CENTRAL IOWA. A
LINE OF THUNDERSTORMS WAS NOW LOCATED FROM NEAR DECORAH TO JUST WEST OF
AMES.

THUNDERSTORMS SHOULD CONTINUE TO BUILD SOUTH TO JUST NORTH OF DES MOINES
DURING THE NEXT HOUR.  LITTLE MOVEMENT WAS DERTECTED ON THE SOUTH END OF
THE LINE.  TORRENTIAL RAIN AND FREQUENT DANGEROUS LIGHTNING ARE THE MAIN
BY-PRODUCTS OF THESE THUNDERSTORMS.

 BELLES
Special weather statement, Jul 19, 9:34 PM CDT, 53 minutes before
IAZ006>011-016>019-026>029-038>040-200335-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
934 PM CDT TUE JUL 19 1994

...A TORNADO WATCH CONTINUES UNTIL MIDNIGHT FOR MUCH OF NORTHEAST
   IOWA...

AT 930 PM CDT...NATIONAL WEATHER SERVICE RADAR IN WATERLOO INDICATED A
LINE OF VERY INTENSE THUNDERSTORMS EXTENDING FROM CHICKSAW
COUNTY NEAR NEW HAMPTON THROUGH SOUTHEAST FLOYD COUNTY THROUGH
NORTHWEST BUTLER COUNTY.  THESE STORMS WERE MOVING EAST SOUTHEAST AT 30
MPH AND WILL MOVE INTO THE PLAINFIELD...CLARKSVILLE...AND ALLISON AREAS
THROUGH 10 PM EVENTUALLY REACHING THE NEW HARTFORD...WAVERLY AND SUMNER
AREAS BY 1020 PM CDT.

THESE STORMS WILL CONTAIN UP TO 1/2" HAIL...VERY HEAVY DOWNPOURS WITH
THE POSSIBILITY OF ONE TO TWO INCHES OF RAIN IN A SHORT TIME...AND WIND
GUSTS NEAR 50 MILES AN HOUR.  TORNADOES ARE ALSO POSSIBLE FROM THESE
STORMS WITH LITTLE OR NO ADVANCE NOTICE.

STAY TUNED TO NOAA WEATHER RADIO AND COMMERCIAL MEDIA TO KEEP INFORMED
OF THIS POTENTIALLY DANGEROUS WEATHER SITUATION.

TRS
Special weather statement, Jul 19, 9:35 PM CDT, 52 minutes before
IAZ006>011-016>019-026>029-038>040-200335-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
934 PM CDT TUE JUL 19 1994

...A TORNADO WATCH CONTINUES UNTIL MIDNIGHT FOR MUCH OF NORTHEAST
   IOWA...

AT 930 PM CDT...NATIONAL WEATHER SERVICE RADAR IN WATERLOO INDICATED A
LINE OF VERY INTENSE THUNDERSTORMS EXTENDING FROM CHICKSAW
COUNTY NEAR NEW HAMPTON THROUGH SOUTHEAST FLOYD COUNTY THROUGH
NORTHWEST BUTLER COUNTY.  THESE STORMS WERE MOVING EAST SOUTHEAST AT 30
MPH AND WILL MOVE INTO THE PLAINFIELD...CLARKSVILLE...AND ALLISON AREAS
THROUGH 10 PM EVENTUALLY REACHING THE NEW HARTFORD...WAVERLY AND SUMNER
AREAS BY 1020 PM CDT.

THESE STORMS WILL CONTAIN UP TO 1/2" HAIL...VERY HEAVY DOWNPOURS WITH
THE POSSIBILITY OF ONE TO TWO INCHES OF RAIN IN A SHORT TIME...AND WIND
GUSTS NEAR 50 MILES AN HOUR.  TORNADOES ARE ALSO POSSIBLE FROM THESE
STORMS WITH LITTLE OR NO ADVANCE NOTICE.

STAY TUNED TO NOAA WEATHER RADIO AND COMMERCIAL MEDIA TO KEEP INFORMED
OF THIS POTENTIALLY DANGEROUS WEATHER SITUATION.

TRS
Special weather statement, Jul 19, 9:40 PM CDT, 47 minutes before
IAZALL-200340-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
940 PM CDT TUE JUL 19 1994

...A TORNADO WATCH IS IN EFFECT FOR NORTH CENTRAL AND NORTHEAST IOWA
   UNTIL MIDNIGHT...

AT 930 PM CDT...STRONG THUNDERSTORMS WERE LOCATED OVER NORTH CENTRAL AND
NORTHEAST IOWA. THE STORMS WERE A 40 MILE WIDE BAND CENTERED FROM JUST
NORTH OF AMES NORTHEAST TO NEAR DECORAH. THE STRONGEST STORMS...CAPABLE
OF PRODUCING FREQUENT LIGHTNING...WIND GUSTS OVER 50 MILES AN
HOUR...SMALL HAIL AND VERY HEAVY RAINFALL WERE LOCATED NEAR DECORAH AND
10 MILES NORTH OF AMES...NEAR STORY CITY.

MOVEMENT WAS EAST AT 25 MILES AN HOUR.

PETERSEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 8:22 PM CDTTornado WarningDMXChickasaw30 min
Jul 19, 8:27 PM CDTTornado WarningDMXHoward18 min
Jul 19, 8:32 PM CDTTornado WarningDMXCerro Gordo28 min
Jul 19, 8:47 PM CDTTornado WarningDMXHoward28 min
Jul 19, 9:38 PM CDTSevere Thunderstorm WarningDMXWinneshiek52 min
Jul 19, 10:15 PM CDTSevere Thunderstorm WarningDMXAllamakee30 min
Jul 20, 1:29 AM CDTSevere Thunderstorm WarningDMXJohnson, Linn31 min
Jul 20, 1:52 AM CDTSevere Thunderstorm WarningDMXJohnson23 min

Nearby

Tornado Warnings in Iowa, 1994Every tornado warning in 1994Tornadoes in 1994

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.