Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 494

April 18, 200316 counties in Oklahoma; 19 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2003, 11:32 PM CDT for 16 counties in Oklahoma; 19 counties in Texas. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
Apr 18, 2003, 11:32 PM CDT (04:32 UTC)
Expired
Apr 19, 2003, 1:30 AM CDT
In force
118 min
Issued by
the Storm Prediction Center
All 35 counties

Beckham County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, McClain County, OK, Oklahoma County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Baylor County, TX, Childress County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Foard County, TX, Garza County, TX, Hall County, TX, Hardeman County, TX, Haskell County, TX, Kent County, TX, King County, TX, Knox County, TX, Lynn County, TX, Motley County, TX, Stonewall County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 102 km from the middle of the area, began a volume at 04:33 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 4.5 hours before the alert went out and 192 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, Amarillo Airport, TX at 00:00Z on 2003-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2003-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3956 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 18, 8:31 PM CDTMesoscale DiscussionSPCCaddo, Cleveland, Comanche, Cotton, Grady, Greer and 8 more2 hr
Apr 18, 9:50 PM CDTSevere Thunderstorm WatchSPCBeckham, Caddo, Canadian, Cleveland, Comanche, Cotton and 13 more6 hr
Apr 19, 12:58 AM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Custer, Dewey, Ellis, Garfield and 6 more2 hr
Apr 19, 1:20 AM CDTTornado WatchSPCComanche, Cotton, Greer, Harmon, Jackson, Kiowa and 2 more7 hr
Apr 19, 1:25 AM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 18 more7 hr
Apr 19, 3:18 AM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Cherokee, Choctaw, Coal and 30 more117 min
Apr 19, 4:11 AM CDTMesoscale DiscussionSPCComanche, Cotton, Jackson, Kiowa, Stephens, Tillman2 hr
Apr 19, 4:52 AM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 14 more113 min
Apr 19, 9:01 AM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Cherokee, Choctaw, Coal and 19 more3 hr
Apr 19, 1:10 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Canadian, Cleveland, Creek, Dewey and 18 more2 hr
Apr 19, 1:15 PM CDTTornado WatchSPCAlfalfa, Blaine, Canadian, Custer, Dewey, Ellis and 14 more7 hr
Apr 19, 2:02 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Cleveland, Coal, Creek and 25 more88 min
Apr 19, 2:30 PM CDTTornado WatchSPCAtoka, Bryan, Cherokee, Choctaw, Coal, Craig and 32 more7 hr
Apr 19, 3:15 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Cleveland, Coal, Creek and 25 more2 hr
Apr 19, 5:50 PM CDTMesoscale DiscussionSPCAlfalfa, Garfield, Grant, Kay, Kingfisher, Noble85 min
Apr 19, 6:07 PM CDTMesoscale DiscussionSPCAdair, Atoka, Cherokee, Choctaw, Coal, Craig and 27 more83 min
Apr 18, 9:21 PM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Comal, Dimmit, Edwards and 12 more54 min

Nearby

Mesoscale Discussions in Texas, 2003Mesoscale Discussions in Oklahoma, 2003Every mesoscale discussion in 2003

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.