Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 119, NWS Des Moines, IA

September 20, 1986Hardin County, Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Sep 20, 1986, 8:42 AM CDT for Hardin County, Story County, Iowa. It was in force for 28 min.

The area

The counties it named.

The facts

Issued
Sep 20, 1986, 8:42 AM CDT (13:42 UTC)
Expired
Sep 20, 1986, 9:10 AM CDT
In force
28 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Hardin County, IA, Story 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, 1.7 hours before the alert went out and 269 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 12:00Z on 1986-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1986-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3632 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
179 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, Sep 20, 4:15 AM CDT, 4 hours 27 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, Sep 20, 5:43 AM CDT, 2 hours 59 minutes before
SPECIAL WEATHER STATEMENT RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
542 AM CDT SAT SEP 20 1986

AT 531 AM CDT...
VERY STRONG THUNDERSTORMS WERE LOCATED OVER NORTHWEST IOWA.  THEY
WERE ABOUT 50 MILES EAST OF SIOUX CITY...BETWEEN CHEROKEE AND ROCK-
WELL CITY.  THESE STORMS WILL PRODUCE VERY HEAVY RAIN...BRIEF GUSTY
WINDS...AND POSSIBLY SOME SMALL HAIL AS THEY PASS OVERHEAD.  THESE
STORMS WERE PART OF A LARGER AREA OF THUNDERSTORMS THAT COVERED ABOUT
THE NORTHWEST THIRD OF THE STATE.

ELSEWHERE...SCATTERED THUNDERSHOWERS CONTINUED OVER THE SOUTHEAST
COUNTIES OF THE STATE.  THEY WERE IN A 50 MILE WIDE BAND BETWEEN
THE RATHBUN RESERVOIR AND THE SOUTHEAST CORNER OF THE STATE.

THE RAIN WAS ALL MOVING NORTHEAST AT 25 MILES AN HOUR.

SCHUMACHER
Special weather statement, Sep 20, 6:45 AM CDT, 1 hour 57 minutes before
SPECIAL WEATHER STATEMENT RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
643 AM CDT SAT SEP 20 1986

AT 634 AM CDT...
VERY STRONG THUNDERSTORMS WERE LOCATED OVER NORTHWEST AND NORTH
CENTRAL IOWA.  THEY WERE IN A 15 MILE WIDE AREA EXTENDING FROM STORM
LAKE TO JUST NORTHEST OF FORT DODGE.  ANOTHER VERY STRONG STORM WAS
LOCATED OVER NORTHEAST NEBRASKA.  IT WILL MOVE INTO NORTHWEST IOWA...
NORTH OF SIOUX CITY BY 715 AM THIS MORNING.  THESE STRONG STORMS WILL
PRODUCE VERY HEAVY RAIN...GUSTY WINDS...AND SOME SMALL HAIL AS THEY
PASS OVERHEAD.  THE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND
STORMS THAT COVERED THE NORTHWEST QUARTER OF IOWA.

ELSEWHERE...SCATTERED SHOWERS AND THUNDERSHOWERS CONTINUED OVER THE
SOUTH TWO TIERS OF IOWAS SOUTH CENTRAL AND SOUTHEAST COUNTIES.

THE RAIN WAS ALL MOVING NORTHEAST AT 30 MILES AN HOUR.

SCHUMACHER

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 7:39 AM CDTSevere Thunderstorm WarningDMXHamilton36 min
Sep 20, 8:17 AM CDTSevere Thunderstorm WarningDMXHamilton28 min
Sep 20, 10:52 AM CDTSevere Thunderstorm WarningDMXIowa, Poweshiek28 min
Sep 20, 11:06 AM CDTFlash Flood WarningDMXMarion114 min
Sep 20, 11:06 AM CDTFlash Flood WarningDMXIowa, Keokuk, Mahaska, Poweshiek114 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1986Every severe thunderstorm warning in 1986

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.