Alert archive / Illinois / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 64, NWS Chicago, IL

June 20, 1997Boone County, Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jun 20, 1997, 7:32 PM CDT for Boone County, Winnebago County, Illinois. It was in force for 58 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 20, 1997, 7:32 PM CDT (00:32 UTC)
Expired: Jun 20, 1997, 8:30 PM CDT
In force: 58 min
Issued by: NWS Chicago, IL
Area: Whole counties

Counties Boone County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 80 km from the middle of the area, began a volume at 00:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.5 hours before the alert went out and 148 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: 4926 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 969 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 216 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

Local storm report, Jun 20, 1:42 PM CDT, 5 hours 50 minutes before

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Local storm report, Jun 20, 2:43 PM CDT, 4 hours 49 minutes before

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Local storm report, Jun 20, 2:47 PM CDT, 4 hours 45 minutes before

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Local storm report, Jun 20, 2:52 PM CDT, 4 hours 40 minutes before

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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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Local storm report, Jun 20, 2:54 PM CDT, 4 hours 38 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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        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 Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 7:48 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	57 min
Jun 20, 8:54 PM CDT	Severe Thunderstorm Warning	LOT	Cook	51 min
Jun 21, 6:16 AM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle	59 min
Jun 21, 6:49 AM CDT	Severe Thunderstorm Warning	LOT	Winnebago	41 min
Jun 21, 3:29 PM CDT	Severe Thunderstorm Warning	LOT	White	46 min
Jun 21, 4:07 PM CDT	Severe Thunderstorm Warning	LOT	Fulton	53 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1997 Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.