Alert archive / Iowa / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 45, NWS Sioux Falls, SD

June 1, 1991Woodbury County, Iowa; Dakota County, Nebraska

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 1, 1991, 1:45 AM CDT for Woodbury County, Iowa; Dakota County, Nebraska. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jun 1, 1991, 1:45 AM CDT (06:45 UTC)
Expired
Jun 1, 1991, 2:45 AM CDT
In force
60 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Woodbury County, IA, Dakota County, NE

The nearest sounding before it

Omaha, NE (KOVN), launched 00:00Z, 6.8 hours before the alert went out and 119 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 1991-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4117 joules per kilogram.LCLLFCEL10008507005003002001001 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 1991-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939Sfc1 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
4117 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1094 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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, May 31, 10:38 PM CDT, 3 hours 7 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, May 31, 10:45 PM CDT, 3 hours before
SDZ018-020-010530-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1035 PM CDT FRI MAY 31 1991

AT 1030 PM CDT RADAR INDICATED INTENSE THUNDERSTORMS OVER EXTREME
SOUTHEAST SOUTH DAKOTA...NORTHWEST IOWA AND NORTHEAST NEBRASKA. OVER
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA THESE THUNDERSTORMS WERE IN A
AREA FROM JUST EAST AKRON IOWA...25 MILES NORTH OF SIOUX CITY IOWA...TO
10 MILES SOUTH OF IRETON IOWA...30 MILES NORTHEAST OF SIOUX CITY. THESE
THUNDERSTORMS WERE MOVING NORTHEAST AT 15 MPH. THESE STORMS WILL BE
MOVING THROUGH SIOUX COUNTY IOWA BY 1230 AM CDT WITH VERY HEAVY RAIN...
POSSIBLE STRONG GUSTY WINDS AND SMALL HAIL. CITIES MOST LIKELY EFFECTED
WOULD BE IRETON...ALTON...SIOUX CENTER AND HULL.

INTENSE THUNDERSTORMS WERE ALSO LOCATED OVER NORTHEAST NEBRASKA..10
MILES SOUTH OF YANTON SOUTH DDAKOTA. THESE STORMS WERE MOVING
EASTNORTHEAST AT 15 MPH. THESE STORMS MAY ALSO PRODUCE VERY HEAVY
RAIN...STRONG GUSTY WINDS AND SMALL HAIL AS THEY MOVE THROUGH SOUTHEAST
YANKTON..AND CLAY COUNTIES OF SOUTH DAKOTA BY 1230 AM CDT. CITIES MOST
LIKELY EFFECTED WOULD BE YANKTON...VOLIN...MECKLING AND VERMILLION.

NO SEVERE WEATHER HAS BEEN REPORTED WITH ANY OF THESE STROMS AT THIS
TIME. HOWEVER PEOPLE THROUGH SOUTHEAST SOUTY DAKOTA..NORTHWEST IOWA AND
SOUTHWEST MINNESOTA ARE ADVISED TO BE ALERT TONIGHT.
BEHREND
Special weather statement, May 31, 11:21 PM CDT, 2 hours 24 minutes before
IAZ001-004-005-010500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1120 PM CDT FRI MAY 31 1991

...SEVERE THUNDRSTORM WATCH IN EFFECT TIL 3 AM FOR DIXON, DAKOTA
AND THURSTON COUNTIES...
...FLASH FLOOD WATCH FOR SIOUXLAND TONIGHT...

AT 11 PM A LINE OF SHOWERS AND THUNDERSTORMS WERE LOCATED FROM
34 MILES NORTHEAST OF SIOUX CITY TO 10 MILES NORTH OF NORFOLK
NEBRASKA. THIS LINE OF STORMS WAS MOVING NORTHEAST AT 10 MPH.
THIS LILNE CONTAINED AREAS OF HEAVY RAIN AND IS MOST LIKELY CAUSING
SOME LOWLAND FLOODING. THERE IS ALSO A TREAT OF SOME STRONG GUSTY
WINDS AND SMALL HAIL IN THIS LINES OF STORMS.

PERSONS LIVING IN LOW LYING AREAS SHOULD STAY ALERT AND WATCH FOR
RISING WKATERS. BE PREPARED TO MOVE TO HIGHER GROUND.

TANNER
Special weather statement, Jun 1, 12:27 AM CDT, 1 hour 18 minutes before
IAZ001-004-005-010600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1227 AM CDT SAT JUN 01 1991

...SEVERE THUNDRSTORM WATCH IN EFFECT TIL 3 AM FOR DIXON, DAKOTA
AND THURSTON COUNTIES...
...FLASH FLOOD WATCH FOR SIOUXLAND TONIGHT...

AT 1210 AM A LINE OF SHOWERS AND THUNDERSTORMS WERE LOCATED FROM
40 MILES NORTHEAST OF SIOUX CITY NEAR ORANGE CITY TO 40 MILES
WEST OF SIOUX CITY. THIS LINE OF STORMS WAS NEAR STATIONARY.
THIS LINE CONTAINED AREAS OF HEAVY RAIN AND IS MOST LIKELY CAUSING
SOME URBAN AND LOWLAND FLOODING IN THE COUNTIES OF PLYMOUTH IN IOWA
AND IN UNION IN SOUTH DAKOTA.

THIS LINE OF STORMS MAY ALSO CONTAIN SMALL HAIL AND GUSTY WINDS
AT TIMES.  AT 1210 AM MAuRBLE SIZE HAIL HAD BEEN REPORTED AT ELKPOINT
SOUTH DAKOTA.
PERSONS LIVING IN LOW LYING AREAS SHOULD BE STAY ALERT AND WATCH
FOR RISING WATER.  YOU SHOULD BE PREPARED TO MOVE TO HIGHER GROUND
FAST.

TANNER
Special weather statement, Jun 1, 12:48 AM CDT, 57 minutes before
SDZ018-020-010630-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1245 AM CDT SAT JUN 1 1991

THUNDERSTORMS OVER EXTREME SOUTHEAST SOUTH DAKOTA...NORTHWEST IOWA AND
NORTHEAST NEBRASKA CONTINUED AT 1230 PM. THE STRONGEST THUNDERSTORMS
WERE NEAR VERMILLION SOUTH DAKOTA AND 5 MILES NORTH OF MERRILL IOWA OR
25 MILES NORTH OF SIOUX CITY. THE THUNDERSTORMS SHOWED LITTLE MOVEMENT
AND ARE EXPECTED TO MOVE LITTLE OVER THE NEXT FEW HOURS.

THESE THUNDERSTORMS HAVE A HISTORY OF VERY HEAVY RAIN...FREQUENT
LIGHTNING STRIKES AND SMALL HAIL. DUE TO THE LIMITED MOVEMENT OF THESE
THUNDERSTORMS...SOME AREAS WILL RECEIVE VERY HEAVY RAINFALL AMOUNTS
RESULTING IN STREET FLOODING AND POOLING O6F WATER IN LOW LYING AREAS.

PEOPLE RESIDING IN THESE AREAS SHOULD REMAIN ALERT TO THE POSSIBILITY
OF SEVERE WEATHER OR FLOODING OF LOW LYING AREAS.

EDDY
Special weather statement, Jun 1, 1:16 AM CDT, 29 minutes before
IAZ001-004-005-010700-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
0115 AM CDT SAT JUN 01 1991

...SEVERE THUNDRSTORM WATCH IN EFFECT TIL 3 AM FOR DIXON, DAKOTA
AND THURSTON COUNTIES...
...FLASH FLOOD WATCH FOR SIOUXLAND TONIGHT...

AT 1 AM A LARGE AREA OF SHOWERS AND THUNDERSTORMS WAS NORTHWEST OF
A LINE FROM 40 MILES NORTHEAST OF SIOUX CITY NEAR ORANGE CITY TO
COLUMBUS NEBRASKA. THIS AREA OF STORMS WAS NEAR STATIONARY AND
PRODUCING VERY HEAVY RAIN SMALL HAIL AND DANGEROUS LIGHTNING. THERE
HAVE BEEN REPORTS OF PEA TO MARBLE SIZE HAIL JUST NORTH OF PONCA
NEBRASKA...20 MILES WEST OF SIOUX CITY AND JUST NORTH OF SIOUX CITY.

WITH THE SLOW MOVEMENT OF THESE STORMS PERSONS IN THE COUNTIES OF
UNION IN SOUTH DAKOTA NEAR THE CITIES OF ELK POINT AND JEFFERSON...
DIXON COUNTY IN NEBRASKA NEAR THE CITIES OF NEWCASTLE AND PONCA...
AND PLYMOUTH COUNTY IN IOWA NEAR THE CITIES OF MERRILL AND LEMARS
CAN EXPECT LOWLAND FLOODING AND SOME STREET OR URBAN FLOODING.

PERSONS IN THESE COUNTIES SHOULD BE ALERT AND WATCH FOR RAPID
RISES IN WATER LEVELS AND BE PREPARED TO MOVE TO HIGHER GROUND.

TANNER

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 2:33 AM CDTFlash Flood WarningFSDPlymouth4 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 1991Severe Thunderstorm Warnings in Nebraska, 1991Every severe thunderstorm warning in 1991

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.