Alert archive / Illinois / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 147, NWS Chicago, IL

July 19, 2008DeKalb County, Lee County, Ogle County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 19, 2008, 11:37 PM CDT for DeKalb County, Lee County, Ogle County, Illinois. It was in force for 53 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: Jul 19, 2008, 11:37 PM CDT (04:37 UTC)
Expired: Jul 20, 2008, 12:30 AM CDT
In force: 53 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon

Counties DeKalb County, IL, Lee County, IL, Ogle County, IL

The radar

The Chicago radar (KLOT), 93 km from the middle of the area, began a volume at 04:40 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 19, 9:35 PM CDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.6 hours before the alert went out and 118 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: 633 J/kg
Mixed-layer CIN: -121 J/kg
Mixed-layer LCL: 1040 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 144 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

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.

NWS Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 19, 3:16 PM CDT, 8 hours 21 minutes earlier.

Area forecast discussion, Jul 19, 3:16 PM CDT, 8 hours 21 minutes before

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Hazardous weather outlook, Jul 19, 3:22 PM CDT, 8 hours 15 minutes before

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  <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.
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        Please try again in a few minutes.
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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 10:53 PM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle	67 min
Jul 20, 1:03 AM CDT	Special Marine Warning	LOT		117 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2008 Every severe thunderstorm warning in 2008

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.