Alert archive / Iowa / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 177, NWS Des Moines, IA

July 27, 1993Linn County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 27, 1993, 9:44 PM CDT for Linn County, Iowa. It was in force for 46 min.

The area

The counties it named.

The facts

Issued
Jul 27, 1993, 9:44 PM CDT (02:44 UTC)
Expired
Jul 27, 1993, 10:30 PM CDT
In force
46 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Linn County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 2.7 hours before the alert went out and 348 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 1993-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 175 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, Minneapolis, MN at 00:00Z on 1993-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939587897Sfc1 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
175 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1555 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 27, 6:40 PM CDT, 3 hours 4 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 27, 6:47 PM CDT, 2 hours 57 minutes before
IAZALL-280040-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
642 PM CDT TUE JUL 27 1993

...A TORNADO WATCH IS IN EFFECT FOR THE EASTERN TWO THIRDS OF IOWA
   UNTIL 10PM...

AT 633 PM CDT...VERY STRONG THUNDERSTORMS PERSISTED OVER CENTRAL IOWA.
THESE STORMS WERE CLUSTERED BETWEEN OGDEN...STORY CITY AND 10 MILES
EAST OF NEVADA...OR WITHIN A 25 MILE RADIUS OF AMES. THE STORMS IN
THIS AREA WILL PRODUCE VERY HEAVY RAIN...FREQUENT DEADLY LIGHTNING
AND SOME PEA TO MARBLE SIZED HAIL.

THESE STORMS WERE PART OF A 25 TO 45 MILE WIDE AREA OF SHOWERS AND
STORMS THAT EXTENDED FROM 45 MILES WEST OF DES MOINES NEAR ADAIR
NORTHEAST TO INDEPENDENCE. INDEPENDENCE IS 20 MILES EAST OF WATERLOO.

ISOLATED THUNDERSTORMS WERE LOCATED 10 MILES SOUTHWEST OF MASON CITY
AND BETWEEN CHARLES CITY AND CRESCO. CHARLES CITY IS 30 MILES EAST
OF WATERRLOO WHILE CRESCO IS 55 MILES NORTHEAST OF MASON CITY.

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

BARLOW/PRENTICE
Special weather statement, Jul 27, 7:51 PM CDT, 1 hour 53 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-280230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
750 PM CDT TUE JUL 27 1993

...THUNDERSTORMS TO AFFECT A GOOD PART OF NORTHEAST IOWA...

AT 740 PM THUNDERSTORMS CONTINUED TO AFFECT AREAS EAST OF I-35 WITH
THE STRONGEST STORMS 10 MILES SOUTH OF WATERLOO NEAR HUDSON.
OTHER STRONG STORMS WERE LOCATED FROM 25 MILES WEST OF DECORAH TO 5
MILES NORTH OF DECORAH. THESE STORMS WERE MOVING EAST AT 25 MPH AND
ARE CAPABLE OF PRODUCING HEAVY RAINS...GUSTY WINDS...SMALL HAIL AND
DEADLY LIGHTNING.

PEOPLE IN THE CITIES OF HUDSON...LAPORTE CITY AND HESPER SHOULD BE
PREPARED TO MOVE TO A PLACE OF SHELTER SHOULD SEVERE WEATHER OCCUR.

SINCE 715 PM THE STORMS HAVE WEAKENED AND THE THREAT OF SEVERE WEATHER
HAS DECREASED BUT STILL EXISTS. THE ONLY REPORT OF SEVERE WEATHER
TONIGHT WAS A 90 MPH WIND GUST AT CONRAD IN GRUNDY COUNTY AT
710 PM.

REMEMBER A TORNADO WATCH REMAINS IN EFFECT UNTIL 10 PM. SHOULD
SEVERE WEATHER APPROACH OR A WARNING BE ISSUED BE SURE TO SEEK
IMMEDIATE SHELTER AND MONITOR NOAA WEATHER RADIO...COMMERCIAL TV
OR RADIO.

COLLAR
Special weather statement, Jul 27, 7:52 PM CDT, 1 hour 52 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-280230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
750 PM CDT TUE JUL 27 1993

...THUNDERSTORMS TO AFFECT A GOOD PART OF NORTHEAST IOWA...

AT 740 PM THUNDERSTORMS CONTINUED TO AFFECT AREAS EAST OF I-35 WITH
THE STRONGEST STORMS 10 MILES SOUTH OF WATERLOO NEAR HUDSON.
OTHER STRONG STORMS WERE LOCATED FROM 25 MILES WEST OF DECORAH TO 5
MILES NORTH OF DECORAH. THESE STORMS WERE MOVING EAST AT 25 MPH AND
ARE CAPABLE OF PRODUCING HEAVY RAINS...GUSTY WINDS...SMALL HAIL AND
DEADLY LIGHTNING.

PEOPLE IN THE CITIES OF HUDSON...LAPORTE CITY AND HESPER SHOULD BE
PREPARED TO MOVE TO A PLACE OF SHELTER SHOULD SEVERE WEATHER OCCUR.

SINCE 715 PM THE STORMS HAVE WEAKENED AND THE THREAT OF SEVERE WEATHER
HAS DECREASED BUT STILL EXISTS. THE ONLY REPORT OF SEVERE WEATHER
TONIGHT WAS A 90 MPH WIND GUST AT CONRAD IN GRUNDY COUNTY AT
710 PM.

REMEMBER A TORNADO WATCH REMAINS IN EFFECT UNTIL 10 PM. SHOULD
SEVERE WEATHER APPROACH OR A WARNING BE ISSUED BE SURE TO SEEK
IMMEDIATE SHELTER AND MONITOR NOAA WEATHER RADIO...COMMERCIAL TV
OR RADIO.

COLLAR
Special weather statement, Jul 27, 9:40 PM CDT, 4 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-280330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
940 PM CDT TUE JUL 27 1993

...LOOK FOR THE STORMS TO GRADUALLY TAPER OFF...

AT 935 PM THUNDERSTORMS CONTINUED MAINLY EAST OF HIGHWAY 63. THE STORM
PRODUCING THE HEAVIEST RAIN WAS LOCATED 10 MILES EAST OF WATERLOO
BETWEEN RAYMOND AND JESUP. THE STROMS WERE MOVING EAST AT NEAR 40 MPH
AND WILL AFFECT JESUP AND INDEPENDENCE THROUGH 1015 PM. OTHER SHOWERS
AND STORMS ARE GOING TO BECOME CONFINED TO AREAS EAST OF HIGHWAY 150
BY 1030 PM.

THE REST OF NORTHEAST IOWA CAN EXPECT SLOWLY CLEARING SKIES INTO
MIDNIGHT.

THE TORNADO WATCH HAS BEEN CANCELLED AS THE THREAT OF SEVERE WEATHER
HAS DIMINISHED.

COLLAR
Special weather statement, Jul 27, 9:42 PM CDT, 2 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-280330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
940 PM CDT TUE JUL 27 1993

...LOOK FOR THE STORMS TO GRADUALLY TAPER OFF...

AT 935 PM THUNDERSTORMS CONTINUED MAINLY EAST OF HIGHWAY 63. THE STORM
PRODUCING THE HEAVIEST RAIN WAS LOCATED 10 MILES EAST OF WATERLOO
BETWEEN RAYMOND AND JESUP. THE STROMS WERE MOVING EAST AT NEAR 40 MPH
AND WILL AFFECT JESUP AND INDEPENDENCE THROUGH 1015 PM. OTHER SHOWERS
AND STORMS ARE GOING TO BECOME CONFINED TO AREAS EAST OF HIGHWAY 150
BY 1030 PM.

THE REST OF NORTHEAST IOWA CAN EXPECT SLOWLY CLEARING SKIES INTO
MIDNIGHT.

THE TORNADO WATCH HAS BEEN CANCELLED AS. THE THREAT OF SEVERE WEATHER
HAS DIMINISHED.

COLLAR

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 7:10 PM CDTSevere Thunderstorm WarningDMXGrundy17 min
Jul 27, 7:14 PM CDTSevere Thunderstorm WarningDMXMarshall21 min
Jul 27, 7:14 PM CDTSevere Thunderstorm WarningDMXTama31 min
Jul 27, 7:44 PM CDTSevere Thunderstorm WarningDMXBenton31 min
Jul 27, 8:08 PM CDTSevere Thunderstorm WarningDMXLinn37 min
Jul 27, 8:10 PM CDTSevere Thunderstorm WarningDMXBuchanan35 min
Jul 27, 9:18 PM CDTSevere Thunderstorm WarningDMXBenton, Iowa27 min
Jul 27, 9:50 PM CDTFlash Flood WarningDMXBenton3 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 1993Every severe thunderstorm 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.