Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 2157

October 29, 2009Washington County, Arkansas; 12 counties in Oklahoma; 25 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 29, 2009, 1:57 PM CDT for Washington County, Arkansas; 12 counties in Oklahoma; 25 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Oct 29, 2009, 1:57 PM CDT (18:57 UTC)
Expired
Oct 29, 2009, 4:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 38 counties

Washington County, AR, Adair County, OK, Cherokee County, OK, Choctaw County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Muskogee County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK, Wagoner County, OK, Anderson County, TX, Bell County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 114 km from the middle of the area, began a volume at 19:00 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

Shreveport, LA (KSHV), launched 12:00Z, 7.0 hours before the alert went out and 246 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, Shreveport, LA at 12:00Z on 2009-10-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 387 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, Shreveport, LA at 12:00Z on 2009-10-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 350 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
387 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
453 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
350 m²/s²
0-3 km storm-relative helicity
422 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.7

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
Oct 29, 1:14 PM CDTTornado WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more8 hr
Oct 29, 1:51 PM CDTTornado WatchSPCBradley, Calhoun, Clark, Cleveland, Dallas, Garland and 13 more7 hr
Oct 29, 3:03 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 23 more117 min
Oct 29, 5:24 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more66 min
Oct 29, 5:27 PM CDTTornado WatchSPCBaxter, Boone, Carroll, Cleburne, Conway, Crawford and 22 more3 hr
Oct 28, 7:12 PM CDTMesoscale DiscussionSPCBeaver, Ellis, Harmon, Roger Mills93 min
Oct 29, 1:07 AM CDTMesoscale DiscussionSPCCarter, Comanche, Cotton, Jefferson, Johnston, Love and 4 more53 min
Oct 29, 1:19 AM CDTTornado WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 11 more6 hr
Oct 29, 1:59 AM CDTTornado WatchSPCBlaine, Caddo, Canadian, Cleveland, Comanche, Cotton and 13 more5 hr
Oct 29, 3:40 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Caddo, Canadian, Carter, Choctaw and 22 more95 min
Oct 29, 5:31 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Cleveland, Coal, Garvin and 8 more89 min
Oct 29, 6:43 AM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Cherokee, Choctaw, Coal and 29 more5 hr
Oct 29, 10:02 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Cherokee, Choctaw, Coal, Craig and 21 more118 min
Oct 29, 11:51 AM CDTTornado WatchSPCAdair, Atoka, Bryan, Cherokee, Choctaw, Coal and 10 more6 hr
Oct 29, 5:03 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Haskell, LeFlore, McCurtain, Muskogee and 1 more57 min
Oct 29, 5:19 AM CDTMesoscale DiscussionSPCAustin, Brazos, Burleson, Chambers, Fort Bend, Grimes and 13 more86 min
Oct 29, 10:48 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Bell, Bosque, Brazos, Burleson and 65 more117 min

Nearby

Mesoscale Discussions in Texas, 2009Mesoscale Discussions in Oklahoma, 2009Mesoscale Discussions in Arkansas, 2009Every mesoscale discussion in 2009

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.