Alert archive / Missouri / Mesoscale Discussions in 2019

Mesoscale Discussion 718

May 21, 20194 states

The Storm Prediction Center issued this mesoscale discussion at May 21, 2019, 12:55 AM CDT for 4 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 21, 2019, 12:55 AM CDT (05:55 UTC)
Expired
May 21, 2019, 2:30 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 42 counties

Clay County, AR, Fulton County, AR, Randolph County, AR, Alexander County, IL, Jackson County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Dunklin County, MO, Franklin County, MO, Gasconade County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Maries County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Perry County, MO, Phelps County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Lake County, TN

The radar

The St Louis radar (KLSX), 135 km from the middle of the area, began a volume at 05:56 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

Springfield, MO (KSGF), launched 00:00Z, 5.9 hours before the alert went out and 271 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, Springfield, MO at 00:00Z on 2019-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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, Springfield, MO at 00:00Z on 2019-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 462 square meters per square second.1939587897Sfc1 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
38 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
992 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
462 m²/s²
0-3 km storm-relative helicity
819 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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 20, 10:30 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Madison and 4 more60 min
May 20, 11:06 PM CDTMesoscale DiscussionSPCBenton24 min
May 21, 12:18 AM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 6 more5 hr
May 21, 5:09 AM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more9 hr
May 21, 7:26 AM CDTMesoscale DiscussionSPCBenton, Crawford, Little River, Polk, Scott, Sebastian and 2 more94 min
May 21, 9:57 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clark, Cleburne, Conway and 26 more93 min
May 21, 11:32 AM CDTTornado WatchSPCBaxter, Boone, Cleburne, Conway, Faulkner, Fulton and 19 more7 hr
May 21, 1:51 PM CDTMesoscale DiscussionSPCBaxter, Boone, Marion, Newton, Pope, Searcy84 min
May 21, 4:43 PM CDTMesoscale DiscussionSPCClay, Craighead, Cross, Greene, Jackson, Lawrence and 3 more62 min
May 21, 3:10 PM CDTTornado WatchSPCAlexander, Bond, Calhoun, Clinton, Fayette, Franklin and 16 more8 hr
May 21, 5:43 PM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Greene, Jackson and 12 more62 min
May 20, 8:20 PM CDTSevere Thunderstorm WatchSPCBenton, Camden, Dent, Hickory, Howell, Laclede and 10 more8 hr
May 21, 6:12 PM CDTMesoscale DiscussionSPCSaint Charles, Saint Louis, City of Saint Louis33 min
May 21, 6:53 PM CDTSevere Thunderstorm WatchSPCAtchison, Holt3 hr

Nearby

Mesoscale Discussions in Missouri, 2019Mesoscale Discussions in Illinois, 2019Mesoscale Discussions in Arkansas, 2019Every mesoscale discussion in 2019

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.