Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 144, NWS Des Moines, IA

July 19, 1994Winneshiek County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 19, 1994, 9:38 PM CDT for Winneshiek County, Iowa. It was in force for 52 min.

The area

The counties it named.

The facts

Issued
Jul 19, 1994, 9:38 PM CDT (02:38 UTC)
Expired
Jul 19, 1994, 10:30 PM CDT
In force
52 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Winneshiek County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 2.6 hours before the alert went out and 223 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

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm 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, 9:15 PM CDT, 23 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Special weather statement, Jul 19, 9:22 PM CDT, 16 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, 12 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 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, 11 minutes 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, 4 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, 3 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

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, 10:15 PM CDTSevere Thunderstorm WarningDMXAllamakee30 min
Jul 19, 10:27 PM CDTTornado WarningDMXAllamakee37 min
Jul 20, 1:29 AM CDTSevere Thunderstorm WarningDMXJohnson, Linn31 min
Jul 20, 1:52 AM CDTSevere Thunderstorm WarningDMXJohnson23 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1994Every severe thunderstorm warning 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.