Alert archive / Indiana / Mesoscale Discussions in 2018

Mesoscale Discussion 482

May 21, 201848 counties in Indiana; 9 counties in Kentucky; 22 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at May 21, 2018, 4:15 PM EDT for 48 counties in Indiana; 9 counties in Kentucky; 22 counties in Ohio. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
May 21, 2018, 4:15 PM EDT (20:15 UTC)
Expired
May 21, 2018, 5:15 PM EDT
In force
60 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 79 counties

Adams County, IN, Bartholomew County, IN, Blackford County, IN, Brown County, IN, Clark County, IN, Crawford County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Dubois County, IN, Fayette County, IN, Floyd County, IN, Franklin County, IN, Gibson County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Harrison County, IN, Henry County, IN, Jackson County, IN, Jay County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Morgan County, IN, Ohio County, IN, Orange County, IN, Owen County, IN, Perry County, IN, Pike County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Spencer County, IN, Switzerland County, IN, Union County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Wayne County, IN, Boone County, KY, Campbell County, KY, Carroll County, KY, Gallatin County, KY, Henry County, KY, Jefferson County, KY, Kenton County, KY, Oldham County, KY, Trimble County, KY, Allen County, OH, Auglaize County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Darke County, OH, Fayette County, OH, Greene County, OH, Hamilton County, OH, Hardin County, OH, Logan County, OH, Madison County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Shelby County, OH, Union County, OH, Van Wert County, OH, Warren County, OH

The radar

The Indianapolis radar (KIND), 87 km from the middle of the area, began a volume at 20:19 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 12:00Z, 8.3 hours before the alert went out and 137 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, Cncnati-Daytn, OH at 12:00Z on 2018-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 133 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, Cncnati-Daytn, OH at 12:00Z on 2018-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
133 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
834 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

As transmitted.

<!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
May 21, 4:59 PM EDTSevere Thunderstorm WatchSPCBartholomew, Decatur, Fayette, Franklin, Hancock, Henry and 6 more6 hr
May 21, 3:30 PM EDTMesoscale DiscussionSPCAthens, Gallia, Lawrence, Meigs, Washington60 min

Nearby

Mesoscale Discussions in Indiana, 2018Mesoscale Discussions in Ohio, 2018Mesoscale Discussions in Kentucky, 2018Every mesoscale discussion in 2018

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.