Alert archive / Illinois / Tornado Warnings in 2026

Tornado Warning 63, NWS Chicago, IL

August 9, 2026LaSalle County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2026, 11:22 PM CDT for LaSalle County, Illinois. It was in force for 23 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: Aug 9, 2026, 11:22 PM CDT (04:22 UTC)
Expired: Aug 9, 2026, 11:45 PM CDT
In force: 23 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County LaSalle County, IL

The radar

The Chicago radar (KLOT), 73 km from the middle of the area, began a volume at 04:22 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
Aug 9, 8:43 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 4.4 hours before the alert went out and 135 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: 3443 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 949 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 334 m²/s²
Significant tornado parameter: 2.1
Supercell composite: 13.5

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Aug 9, 7:21 PM CDT, 4 hours 1 minute earlier.

Area forecast discussion, Aug 9, 7:21 PM CDT, 4 hours 1 minute before

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In the hours before

Local storm report, Aug 9, 8:15 PM CDT, 3 hours 7 minutes before

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Local storm report, Aug 9, 8:19 PM CDT, 3 hours 3 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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      <p id="message2">
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Local storm report, Aug 9, 8:35 PM CDT, 2 hours 47 minutes before

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    <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.
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Local storm report, Aug 9, 10:41 PM CDT, 41 minutes before

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<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.
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Local storm report, Aug 9, 11:04 PM CDT, 18 minutes before

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<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>
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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 8:41 PM CDT	Severe Thunderstorm Warning	LOT	Lee	64 min
Aug 9, 9:09 PM CDT	Areal Flood Advisory	LOT	Lee	4 hr
Aug 9, 9:39 PM CDT	Severe Thunderstorm Warning	LOT	Lee	66 min
Aug 9, 9:49 PM CDT	Tornado Warning	LOT	Lee	41 min
Aug 9, 10:10 PM CDT	Flash Flood Warning	LOT	Lee	3 hr
Aug 9, 10:16 PM CDT	Areal Flood Advisory	LOT	DeKalb, LaSalle	78 min
Aug 9, 10:23 PM CDT	Tornado Warning	LOT	Lee	26 min
Aug 9, 10:49 PM CDT	Areal Flood Advisory	LOT	LaSalle	45 min
Aug 9, 11:10 PM CDT	Special Marine Warning	LOT		95 min
Aug 9, 11:22 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Lake	38 min
Aug 9, 11:23 PM CDT	Areal Flood Advisory	LOT	Grundy, Kendall, LaSalle, Livingston	3 hr
Aug 9, 11:32 PM CDT	Areal Flood Advisory	LOT	DeKalb, LaSalle	2 hr
Aug 9, 11:35 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Grundy, LaSalle, Livingston	70 min
Aug 9, 11:36 PM CDT	Tornado Warning	LOT	LaSalle	24 min
Aug 9, 11:47 PM CDT	Flash Flood Warning	LOT	Grundy, LaSalle, Livingston	3 hr
Aug 9, 11:54 PM CDT	Special Marine Warning	LOT		96 min
Aug 9, 11:59 PM CDT	Tornado Warning Tornado observed	LOT	Grundy, LaSalle	17 min
Aug 10, 12:01 AM CDT	Flash Flood Warning	LOT	LaSalle	2 hr
Aug 10, 12:36 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Grundy, Iroquois, Kankakee, Livingston	69 min
Aug 10, 12:39 AM CDT	Tornado Warning	LOT	Ford, Kankakee, Livingston	36 min
Aug 10, 12:40 AM CDT	Special Marine Warning	LOT		45 min
Aug 10, 12:44 AM CDT	Areal Flood Advisory	LOT	Ford, Iroquois, Kankakee, Livingston	2 hr
Aug 10, 12:54 AM CDT	Tornado Warning	LOT	Livingston	36 min
Aug 10, 1:05 AM CDT	Areal Flood Advisory	LOT	Grundy, Kendall, LaSalle, Lee	8 hr
Aug 10, 1:18 AM CDT	Flash Flood Warning	LOT	Ford, Kankakee, Livingston	91 min
Aug 10, 1:20 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois	55 min
Aug 10, 1:28 AM CDT	Tornado Warning	LOT	Iroquois	16 min
Aug 10, 1:31 AM CDT	Tornado Warning	LOT	Ford, Livingston	29 min
Aug 10, 1:42 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Livingston	93 min
Aug 10, 1:52 AM CDT	Flash Flood Warning	LOT	Ford, Iroquois, Kankakee	58 min
Aug 10, 1:56 AM CDT	Areal Flood Advisory	LOT	Ford, Iroquois, Livingston	58 min
Aug 10, 2:32 AM CDT	Areal Flood Warning	LOT	Grundy, LaSalle, Livingston	3 hr
Aug 10, 2:48 AM CDT	Areal Flood Advisory	LOT	Ford, Grundy, Iroquois, Kankakee, Livingston	7 hr
Aug 9, 7:15 PM CDT	Areal Flood Advisory	LOT	Lake, Porter	2 hr

Nearby

Tornado Warnings in Illinois, 2026 Every tornado warning in 2026 Tornadoes in 2026

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.