Alert archive / Kentucky / Mesoscale Discussions in 2012

Mesoscale Discussion 1857

September 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Sep 1, 2012, 7:56 PM CDT for 4 states. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Sep 1, 2012, 7:56 PM CDT (00:56 UTC)
Expired
Sep 1, 2012, 9:30 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 26 counties

Gallatin County, IL, Hardin County, IL, Massac County, IL, Pope County, IL, White County, IL, Gibson County, IN, Posey County, IN, Vanderburgh County, IN, Warrick County, IN, Caldwell County, KY, Calloway County, KY, Crittenden County, KY, Graves County, KY, Henderson County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Carroll County, TN, Henry County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 45 km from the middle of the area, began a volume at 00:59 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

Nashville Metro, TN (KBNA), launched 00:00Z, 0.9 hours before the alert went out and 181 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, Nashville Metro, TN at 00:00Z on 2012-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1909 joules per kilogram.LCLLFCEL10008507005003002001001 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, Nashville Metro, TN at 00:00Z on 2012-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 square meters per square second.1939Sfc1 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
1909 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1040 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
160 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

<!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>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 7:13 PM CDTMesoscale DiscussionSPCChampaign, Clark, Edgar, Vermilion62 min
Sep 1, 9:37 PM CDTMesoscale DiscussionSPCVanderburgh, Warrick23 min
Sep 2, 2:20 PM CDTMesoscale DiscussionSPCAdair, Allen, Barren, Boyle, Casey, Clinton and 15 more115 min
Sep 2, 2:49 PM CDTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 37 more7 hr
Sep 2, 6:35 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 34 more85 min
Sep 1, 7:08 PM CDTSevere Thunderstorm WatchSPCCarroll, Chester, Decatur, Fayette, Hardeman, Hardin and 4 more6 hr
Sep 1, 9:59 PM CDTMesoscale DiscussionSPCChester, Decatur, Hardeman, Henderson, McNairy91 min
Sep 2, 3:42 PM CDTTornado WatchSPCChester, Decatur, Fayette, Hardeman, Hardin, McNairy and 1 more7 hr
Sep 2, 5:13 PM CDTMesoscale DiscussionSPCBradley, Hamilton, Loudon, McMinn, Meigs, Monroe and 2 more62 min
Sep 2, 5:33 PM CDTSevere Thunderstorm WatchSPCBradley, Hamilton, McMinn, Meigs, Monroe, Polk and 1 more5 hr

Nearby

Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Indiana, 2012Every mesoscale discussion in 2012

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.