Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 566

April 25, 201117 counties in Arkansas; 4 parishes in Louisiana; 9 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2011, 7:23 AM CDT for 17 counties in Arkansas; 4 parishes in Louisiana; 9 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2011, 7:23 AM CDT (12:23 UTC)
Expired: Apr 25, 2011, 9:00 AM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 30 counties

Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Saline County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Webster Parish, LA, Bowie County, TX, Camp County, TX, Cass County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Smith County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 113 km from the middle of the area, began a volume at 12:23 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.

Tornado Watch 201Apr 25, 11:00 AM CDT

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 0.4 hours before the alert went out and 110 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1213 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 491 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 11.5

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.

Issued	Product	Office	Counties	Lasted
Apr 24, 10:13 PM CDT	Mesoscale Discussion	SPC	Clark, Cleburne, Conway, Faulkner, Garland, Grant and 15 more	2 hr
Apr 24, 11:43 PM CDT	Severe Thunderstorm Watch	SPC	Hempstead, Howard, Little River, Miller, Nevada, Sevier	5 hr
Apr 25, 1:57 AM CDT	Mesoscale Discussion	SPC	Cleveland, Dallas, Jefferson, Lincoln	63 min
Apr 25, 4:41 AM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more	7 hr
Apr 25, 8:37 AM CDT	Mesoscale Discussion	SPC	Arkansas, Cleveland, Crittenden, Desha, Drew, Jefferson and 7 more	53 min
Apr 25, 9:17 AM CDT	Severe Thunderstorm Watch	SPC	Crittenden, Lee, Phillips, St. Francis	6 hr
Apr 25, 10:46 AM CDT	Mesoscale Discussion	SPC	Hempstead, Howard, Lafayette, Little River, Miller, Sevier	59 min
Apr 25, 11:00 AM CDT	Tornado Watch	SPC	Carroll, Clark, Crawford, Franklin, Hempstead, Howard and 13 more	7 hr
Apr 25, 1:15 PM CDT	Mesoscale Discussion	SPC	Crittenden, Cross, Lee, Phillips, St. Francis	60 min
Apr 25, 1:28 PM CDT	Mesoscale Discussion	SPC	Crawford, Franklin, Howard, Johnson, Little River, Logan and 5 more	92 min
Apr 25, 3:08 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 29 more	37 min
Apr 25, 3:22 PM CDT	Tornado Watch PDS	SPC	Arkansas, Baxter, Boone, Bradley, Calhoun, Clark and 50 more	8 hr
Apr 25, 4:34 PM CDT	Mesoscale Discussion	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 11 more	56 min
Apr 25, 4:50 PM CDT	Tornado Watch PDS	SPC	Clay, Craighead, Crittenden, Cross, Greene, Lee and 4 more	7 hr
Apr 24, 7:35 PM CDT	Mesoscale Discussion	SPC	Carson, Gray, Hansford, Hemphill, Hutchinson, Lipscomb and 5 more	2 hr
Apr 24, 8:48 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Callahan, Coleman, Collin, Comanche and 36 more	117 min
Apr 24, 11:25 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Callahan, Camp, Coke, Coleman and 39 more	65 min
Apr 24, 11:58 PM CDT	Mesoscale Discussion	SPC	Hemphill, Lipscomb, Ochiltree	92 min
Apr 25, 3:29 AM CDT	Mesoscale Discussion	SPC	Bosque, Camp, Collin, Dallas, Delta, Denton and 24 more	61 min
Apr 25, 2:16 PM CDT	Mesoscale Discussion	SPC	Angelina, Bastrop, Bell, Blanco, Brazos, Burleson and 27 more	59 min
Apr 25, 2:41 PM CDT	Tornado Watch	SPC	Anderson, Angelina, Bastrop, Bell, Blanco, Bosque and 49 more	9 hr
Apr 25, 5:21 PM CDT	Mesoscale Discussion	SPC	Bosque, Delta, Ellis, Henderson, Hill, Hopkins and 7 more	54 min
Apr 25, 5:24 PM CDT	Mesoscale Discussion	SPC	Armstrong, Carson, Childress, Collingsworth, Donley, Gray and 3 more	66 min
Apr 25, 6:57 PM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Bell, Blanco, Brazos, Burleson and 22 more	2 hr

Nearby

Mesoscale Discussions in Arkansas, 2011 Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Louisiana, 2011 Every 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.