Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 527

April 22, 20116 counties in Arkansas; 22 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2011, 9:39 PM CDT for 6 counties in Arkansas; 22 counties in Oklahoma. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Apr 22, 2011, 9:39 PM CDT (02:39 UTC)
Expired
Apr 22, 2011, 10:45 PM CDT
In force
66 min
Issued by
the Storm Prediction Center
All 28 counties

Carroll County, AR, Crawford County, AR, Franklin County, AR, Madison County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Marshall County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Sequoyah County, OK, Stephens County, OK

The radar

The Western Arkansas radar (KSRX), 91 km from the middle of the area, began a volume at 02:39 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

Springfield, MO (KSGF), launched 00:00Z, 2.7 hours before the alert went out and 247 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 2011-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2835 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 2011-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 231 square meters per square second.19395878Sfc1 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
2835 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
231 m²/s²
0-3 km storm-relative helicity
254 m²/s²
Significant tornado parameter
4.7
Supercell composite
18.1

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
Apr 22, 7:29 PM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Fulton, Greene, Izard and 7 more91 min
Apr 22, 8:09 PM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Madison, Washington96 min
Apr 22, 11:04 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Madison, Marion and 3 more7 hr
Apr 22, 11:10 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 4 more2 hr
Apr 23, 2:33 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Marion, Washington87 min
Apr 23, 5:06 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Marion, Newton and 1 more24 min
Apr 23, 1:04 PM CDTMesoscale DiscussionSPCClay, Craighead, Mississippi86 min
Apr 23, 5:02 PM CDTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Crawford and 21 more58 min
Apr 23, 5:09 PM CDTMesoscale DiscussionSPCBaxter, Clay, Fulton, Randolph2 hr
Apr 23, 5:38 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 30 more6 hr
Apr 22, 11:35 PM CDTSevere Thunderstorm WatchSPCAtoka, Carter, Cleveland, Coal, Comanche, Cotton and 19 more4 hr
Apr 23, 2:08 AM CDTMesoscale DiscussionSPCLatimer, LeFlore, Pittsburg, Pushmataha67 min
Apr 23, 12:56 PM CDTMesoscale DiscussionSPCBryan, Carter, Choctaw, Jefferson, Johnston, Love and 2 more64 min
Apr 23, 3:05 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Cotton and 11 more9 hr

Nearby

Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Arkansas, 2011Every mesoscale discussion in 2011

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.