Alert archive / Illinois / Areal Flood Advisories in 2021

Areal Flood Advisory 24, NWS Lincoln, IL

August 9, 20214 counties in Illinois

NWS Lincoln, IL issued this areal flood advisory at Aug 9, 2021, 6:28 AM CDT for 4 counties in Illinois. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Aug 9, 2021, 6:28 AM CDT (11:28 UTC)
Expired: Aug 9, 2021, 9:44 AM CDT
In force: 3 hr
Issued by: NWS Lincoln, IL
Area: Storm-based polygon

Counties Christian County, IL, Macon County, IL, Moultrie County, IL, Shelby County, IL

The radar

The Lincoln radar (KILX), 70 km from the middle of the area, began a volume at 11:27 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

Lincoln, IL (KILX), launched 00:00Z, 11.5 hours before the alert went out and 66 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: 2009 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1044 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 34 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Lincoln, IL wrote its last area forecast discussion before this areal flood advisory went out at Aug 9, 5:22 AM CDT, 1 hour 6 minutes earlier.

Area forecast discussion, Aug 9, 5:22 AM CDT, 1 hour 6 minutes before

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Hazardous weather outlook, Aug 9, 5:28 AM CDT, 1 hour before

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In the hours before

Local storm report, Aug 9, 12:40 AM CDT, 5 hours 48 minutes before

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Local storm report, Aug 9, 3:05 AM CDT, 3 hours 23 minutes before

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</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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      <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, 5:07 AM CDT, 1 hour 21 minutes before

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<html lang="en">
<head>
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  <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>
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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 7:20 PM CDT	Areal Flood Advisory	ILX	McLean	115 min
Aug 9, 2:26 AM CDT	Areal Flood Advisory	ILX	Clay	3 hr
Aug 9, 7:07 AM CDT	Areal Flood Advisory	ILX	Logan, Menard, Sangamon	3 hr
Aug 9, 10:50 AM CDT	Areal Flood Advisory	ILX	Clay, Crawford, Effingham, Jasper	2 hr
Aug 9, 1:54 PM CDT	Heat Advisory	ILX	Cass, Champaign, Christian, Clark, Clay, Coles and 29 more	29 hr
Aug 9, 3:07 PM CDT	River Flood Warning	ILX	Clay, Richland	6 days

Nearby

Areal Flood Advisories in Illinois, 2021 Every areal flood advisory in 2021

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.