Alert archive / Iowa / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 9, NWS Des Moines, IA

May 18, 1987Decatur County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 18, 1987, 5:23 PM CDT for Decatur County, Iowa. It was in force for 67 min.

The area

The counties it named.

The facts

Issued: May 18, 1987, 5:23 PM CDT (22:23 UTC)
Expired: May 18, 1987, 6:30 PM CDT
In force: 67 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Decatur County, IA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 226 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3611 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: 7 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 18, 1:18 PM CDT, 4 hours 5 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
115 PM CDT MON MAY 18 1987

...AN AREA OF STRONG THUNDERSTORMS DEVELOP IN NORTHEAST AND
   CENTRAL IOWA...

AT 115 PM CDT THE NATIONAL WEATHER SERVICE RADAR AT WATERLOO WAS
SHOWING SEVERAL AREA OF STRONG THUNDERSTORMS...ONE AREA WAS NORTHEAST
OF WATERLOO IN A 30 MILE WIDE BAND FROM NEW HAMPTON TO NEAR OELWEIN.
THE OTHER AREA OF THUNDERSTORMS WAS LOCATED IN A 20 MILE WIDE BAND
FROM WINTERSET JUST SOUTHWEST OF DES MOINES TO IOWA FALLS 40 MILES
WEST OF WATERLOO.

THESE AREAS OF THUNDERSTORMS WERE DEVELOPING AND DYING RAPIDLY AND
WILL PRODUCE FREQUENT LIGHTNING STRIKES, STRONG GUSTY WINDS TO 40
MPH, BRIEF HEAVY RAINS AND EVEN SOME SMALL HAIL IS POSSIBLE AS
THEY MOVE NORTHEAST AND EAST AROUND 20 MPH.
ROBB

Special weather statement, May 18, 2:41 PM CDT, 2 hours 42 minutes before

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Special weather statement, May 18, 2:42 PM CDT, 2 hours 41 minutes before

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Special weather statement, May 18, 3:42 PM CDT, 1 hour 41 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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Special weather statement, May 18, 4:45 PM CDT, 38 minutes before

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<head>
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  <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
May 18, 1:48 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Union	37 min
May 18, 6:22 PM CDT	Severe Thunderstorm Warning	DMX	Wayne	50 min
May 18, 6:31 PM CDT	Severe Thunderstorm Warning	DMX	Iowa	29 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1987 Every severe thunderstorm warning in 1987

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.