Alert archive / Illinois / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 274, NWS Quad Cities, IA

August 5, 2008Muscatine County, Scott County, Iowa; Henry County, Mercer County, Rock Island County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 5, 2008, 6:08 AM CDT for Muscatine County, Scott County, Iowa; Henry County, Mercer County, Rock Island County, Illinois. It was in force for 22 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 5, 2008, 6:08 AM CDT (11:08 UTC)
Expired
Aug 5, 2008, 6:30 AM CDT
In force
22 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

Counties Muscatine County, IA, Scott County, IA, Henry County, IL, Mercer County, IL, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 21 km from the middle of the area, began a volume at 11:11 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.

IssuedProductOfficeLasted
Aug 5, 2:55 AM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 11.1 hours before the alert went out and 24 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, Davenport, at 00:00Z on 2008-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6781 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 2008-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
6781 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
790 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
239 m²/s²
Significant tornado parameter
7.9
Supercell composite
32.9

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 Quad Cities, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 5, 2:56 AM CDT, 3 hours 12 minutes earlier.

Area forecast discussion, Aug 5, 2:56 AM CDT, 3 hours 12 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
256 AM CDT TUE AUG 5 2008

.SYNOPSIS...
COLD FRONT EXTENDS FROM NORTHWEST IL TO EASTERN IA TO NORTHWEST MO
WILL MOVE THROUGH THE CWA TODAY. THEN NORTHWEST FLOW ALOFT DOMINATES
FOR THE REMAINDER OF THE WEEK FOR AN EXTENDED PERIOD OF QUIET
WEATHER. ECMWF HINTS AT STRONG WARM FRONT RETURNING ABOUT SUNDAY
WITH DECENT WARM AIR ADVECTION THUNDERSTORMS DEVELOPING.

&&

.SHORT TERM...TODAY AND TONIGHT...
COLD FRONT EXTENDS FROM NORTHWEST IL TO EASTERN IA TO NORTHWEST MO
AND WILL CONTINUE SLIDING TO THE SOUTHEAST TODAY. THUNDERSTORMS HAVE
ERUPTED LAST COUPLE OF HOURS IN OUR IA CWA AHEAD OF FRONT FROM I-80
SOUTHWARD. CAP ERODING AS COOLER MID LEVEL TEMPERATURES SPREAD SOUTH
INTO THE AREA...WITH LOW LEVEL JET POINTED INTO SOUTHERN IA.
THUNDERSTORMS FEEDING ON VERY UNSTABLE AIR WITH MSAS SHOWING LI OF
-9 IN SOUTHEAST IA AND DEWPOINT OF 78 AT BRL. ALREADY GETTING SEVERE
WEATHER REPORTS AND WILL HAVE SEVERE MENTIONED IN GRIDS FOR THIS
MORNING. POTENTIAL EXISTS FOR SIGNIFICANT WIND DAMAGE AS LARGER BOW
ECHO BEGINNING TO TAKE SHAPE. WILL ALSO HAVE LIKELY POPS ESPECIALLY
SOUTH OF I-80. MAIN ACTION SHOULD SHIFT OFF THE EAST OF THE CWA
LATER THIS MORNING AND WILL CARRY ONLY SMALL CHANCE IN OUR FAR
SOUTHERN CWA THIS AFTERNOON. WILL GO WITH HIGHS THIS AFTERNOON IN
THE 80S WITH GRADUALLY LOWERING HUMIDITY VALUES. THEN COOLER AND
DRIER AIR FEEDING INTO THE CWA OVERNIGHT BEHIND FRONT.

.LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
WEDNESDAY THROUGH SATURDAY...NORTHWEST FLOW ALOFT DOMINATES THIS
PERIOD WITH BELOW NORMAL TEMPERATURES AND COMFORTABLE HUMIDITIES.
RATHER LARGE CANADIAN HIGH PRESSURE BUILDS INTO THE REGION SO QUIET
WEATHER EXPECTED. 850 MB TEMPERATURES ARE PROGGED BY THE ECMWF MODEL
TO BE 12 TO 14C ACROSS THE CWA WHICH SUPPORTS RATHER PLEASANT
TEMPERATURES FOR AUGUST.

SUNDAY...ECMWF INDICATES STRONG WARM FRONT LIFTING TOWARDS THE
MIDWEST WITH SIGNALS SUPPORTING AN MCS DEVELOPING IN THE DVN CWA.
WILL PASS CONCERNS TO THE NEXT SHIFT TO EVALUATE FOR ADDING POPS ON
SUNDAY.

&&

.AVIATION...
THUNDERSTORMS THIS MORNING SHOULD AFFECT KMLI/KBRL SITES AS COLD
FRONT MOVES INTO THE REGION. DRIER AIR FILTERING INTO THE AREA FROM
THE NORTH THIS AFTERNOON SHOULD ENSURE VFR CONDITIONS...WHICH WILL
CONTINUE THROUGH TUESDAY NIGHT.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.

&&

HAASE
Hazardous weather outlook, Aug 5, 4:58 AM CDT, 1 hour 10 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>

In the hours before

Local storm report, Aug 5, 4:23 AM CDT, 1 hour 45 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>
Local storm report, Aug 5, 4:28 AM CDT, 1 hour 40 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>
Local storm report, Aug 5, 5:31 AM CDT, 37 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>
Local storm report, Aug 5, 5:34 AM CDT, 34 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>
Local storm report, Aug 5, 5:50 AM CDT, 18 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>
Local storm report, Aug 5, 5:52 AM CDT, 16 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>

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 5, 2:01 AM CDTSevere Thunderstorm WarningDVNJefferson, Keokuk, Washington74 min
Aug 5, 2:51 AM CDTSevere Thunderstorm WarningDVNDes Moines, Henry, Louisa, Muscatine, Washington69 min
Aug 5, 6:20 AM CDTSevere Thunderstorm WarningDVNIowa, Johnson, Keokuk, Louisa, Muscatine, Washington40 min
Aug 4, 7:03 PM CDTSevere Thunderstorm WarningDVNWhiteside27 min
Aug 5, 3:25 AM CDTSevere Thunderstorm WarningDVNHenderson, Mercer, Rock Island, Warren72 min
Aug 5, 4:00 AM CDTSevere Thunderstorm WarningDVNBureau, Henry, Putnam73 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2008Severe Thunderstorm Warnings in Iowa, 2008Every 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.