Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 484

April 13, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2007, 8:42 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 13, 2007, 8:42 PM CDT (01:42 UTC)
Expired
Apr 13, 2007, 10:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 125 counties

Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Union County, AR, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Bryan County, OK, Choctaw County, OK, Love County, OK, Marshall County, OK, Anderson County, TX, Angelina County, TX, Austin County, TX, Bell County, TX, Bosque County, TX, Bowie County, TX, Brazos County, TX, Brown County, TX, Burleson County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Grayson County, TX, Gregg County, TX, Grimes County, TX, Hamilton County, TX, Hardin County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Jasper County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Marion County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Montague County, TX, Montgomery County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Newton County, TX, Orange County, TX, Palo Pinto County, TX, Panola County, TX, Parker County, TX, Polk County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, San Saba County, TX, Shelby County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Trinity County, TX, Tyler County, TX, Upshur County, TX, Van Zandt County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Williamson County, TX, Wise County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 119 km from the middle of the area, began a volume at 01:42 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 00:00Z, 1.7 hours before the alert went out and 127 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 00:00Z on 2007-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1090 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 00:00Z on 2007-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 557 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
1090 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
629 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
557 m²/s²
0-3 km storm-relative helicity
778 m²/s²
Significant tornado parameter
0.0
Supercell composite
33.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 13, 10:55 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 19 more95 min
Apr 14, 1:41 AM CDTTornado WatchSPCAshley, Chicot6 hr
Apr 14, 1:34 AM CDTMesoscale DiscussionSPCAllen, Avoyelles, Caldwell, Catahoula, Concordia, East Carroll and 14 more56 min
Apr 14, 6:17 AM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafayette and 13 more88 min
Apr 14, 7:11 AM CDTSevere Thunderstorm WatchSPCEast Baton Rouge, East Feliciana, Livingston, Pointe Coupee, Saint Helena, Saint Tammany and 4 more6 hr
Apr 14, 5:04 PM CDTMesoscale DiscussionSPCPlaquemines, Saint Bernard56 min
Apr 13, 9:54 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 28 more2 hr

Nearby

Mesoscale Discussions in Texas, 2007Mesoscale Discussions in Louisiana, 2007Mesoscale Discussions in Arkansas, 2007Every mesoscale discussion in 2007

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.