Alert archive / Iowa / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 231, NWS Des Moines, IA

August 18, 1993Marion County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 18, 1993, 5:17 PM CDT for Marion County, Iowa. It was in force for 43 min.

The area

The counties it named.

The facts

Issued: Aug 18, 1993, 5:17 PM CDT (22:17 UTC)
Expired: Aug 18, 1993, 6:00 PM CDT
In force: 43 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Marion County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.3 hours before the alert went out and 273 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1510 J/kg
Mixed-layer CIN: -153 J/kg
Mixed-layer LCL: 1800 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 20 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, Aug 18, 4:09 PM CDT, 1 hour 8 minutes before

IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-182200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
410 PM CDT WED AUG 18 1993

...SEVERE THUNDERSTORM WATCH FOR PORTIONS OF EAST CENTRAL IOWA...

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED ROUGHLY FOR AREAS ALONG
AND SOUTH OF HIGHWAY 20 INCLUDING WATERLOO...GRUNDY CENTER...AND THE
INDEPENDENCE AREA THROUGH 8 PM TONIGHT.

AT 400 PM RADAR INDICATED INTENSE SHOWERS AND THUNDERSTORMS FROM CENTRAL
INTO NORTH CENTRAL IOWA. THESE STORMS WERE MOVING EAST AT 35 MILES
AN HOUR. ANOTHER SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS
CONTINUED ALONG THE MISSISSIPPI RIVER TO THE SOUTH OF HIGHWAY 18.

SHOWERS AND THUNDERSTORMS WITH BRIEF HEAVY RAIN...SMALL HAIL AND WIND
GUST TO 40 MILES AN HOUR ARE GOING TO MOVE INTO THE MASON CITY...HAMPTON
AND ST. ANSGAR AREAS THROUGH 5 PM AND WILL CONTINUE IN THE FOREST CITY
AND GARNER AREAS THROUGH THE EARLY EVENINGZ HOURS.

A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE STATE.
STAY TUNED TO NOAA WEATHER RADIO...LOCAL WEATHER RADIO AND TELEVISION
FOR ADDITIONAL UPDATES AND POSSIBLE WARNINGS.

TRS/PABST

Special weather statement, Aug 18, 4:09 PM CDT, 1 hour 8 minutes before

IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-182200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IAED AUG 18 1993

...SEVERE THUNDERSTORM WATCH FOR PORTIONS OF EAST CENTRAL IOWA...

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED ROUGHLY FOR AREAS ALONG
AND SOUTH OF HIGHWAY 20 INCLUDING WATERLOO...GRUNDY CENTER...AND THE
INDEPENDENCE AREA THROUGH 8 PM TONIGHT.

AT INDICATED INTENSE SHOWERS AND THUNDERSTORMS FROM CENTRAL
INTO NORTH CENTRAL IOWA. THESE STORMS WERE MOVING EAST AT 35 MILES
AN HOUR. ANOTHER SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS
CONTINUED ALONG THE MISSISSIPPI RIVER TO THE SOUTH OF HIGHWAY 18.

SHOWERS AND T HEAVY RAIN...SMALL HAIL AND WIND
GUST TO 40 MILES AN HOUR ARE GOING TO MOVE INTO THE MASON CITY...HAMPTON
AND ST. ANSGAR AREAS THROUGH 5 PM AND WILL CONTINUE IN THE FOREST CITY
AND GARNER AREAS THROUGH THE EARLY EVENING HOURS.

A FLASH FLOOD WATCH REMAINS IN EFFECT FORTATE.
STAY TUNED TO NOAA WEATHER RADIO...LOCAL WEATHER RADIO AND TELEVISION
FOR ADDITIONAL UPDATES AND POSSIBLE WARNINGS.

TRS/PABST

Special weather statement, Aug 18, 5:00 PM CDT, 17 minutes before

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Special weather statement, Aug 18, 5:02 PM CDT, 15 minutes before

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Special weather statement, Aug 18, 5:10 PM CDT, 7 minutes before

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<head>
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  <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.
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      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
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Special weather statement, Aug 18, 5:10 PM CDT, 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.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 5:30 AM CDT	Flash Flood Warning	DMX	Iowa	3 hr
Aug 18, 12:53 PM CDT	Severe Thunderstorm Warning	DMX	Johnson, Linn	22 min
Aug 18, 1:21 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	54 min
Aug 18, 2:07 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll	53 min
Aug 18, 2:14 PM CDT	Severe Thunderstorm Warning	DMX	Sac	46 min
Aug 18, 2:29 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Greene	46 min
Aug 18, 2:54 PM CDT	Severe Thunderstorm Warning	DMX	Greene, Guthrie	51 min
Aug 18, 3:11 PM CDT	Severe Thunderstorm Warning	DMX	Adair	34 min
Aug 18, 3:13 PM CDT	Severe Thunderstorm Warning	DMX	Webster	47 min
Aug 18, 3:29 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Madison	46 min
Aug 18, 3:38 PM CDT	Flash Flood Warning	DMX	Greene	3 hr
Aug 18, 3:38 PM CDT	Flash Flood Warning	DMX	Greene	3 hr
Aug 18, 3:56 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Story	64 min
Aug 18, 4:25 PM CDT	Flash Flood Warning	DMX	Polk	4 hr
Aug 18, 4:25 PM CDT	Severe Thunderstorm Warning	DMX	Warren	50 min
Aug 18, 5:07 PM CDT	Severe Thunderstorm Warning	DMX	Keokuk, Mahaska	38 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1993 Every 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.