Alert archive / Mississippi / Mesoscale Discussions in 2011

Mesoscale Discussion 582

April 25, 20118 states

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2011, 11:05 PM CDT for 8 states. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2011, 11:05 PM CDT (04:05 UTC)
Expired: Apr 26, 2011, 1:00 AM CDT
In force: 115 min
Issued by: the Storm Prediction Center

All 113 counties

Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Ashley County, AR, Chicot County, AR, Gallatin County, IL, Hardin County, IL, Massac County, IL, Pope County, IL, Saline County, IL, White County, IL, Posey County, IN, Vanderburgh County, IN, Ballard County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, East Carroll Parish, LA, Morehouse Parish, LA, West Carroll Parish, LA, Alcorn County, MS, Attala County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, DeSoto County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Washington County, MS, Webster County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN

The radar

The Memphis radar (KNQA), 42 km from the middle of the area, began a volume at 04:08 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.

Severe Thunderstorm Watch 211Apr 25, 11:45 PM CDT

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 4.1 hours before the alert went out and 59 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: 1507 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 914 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 388 m²/s²
0-3 km storm-relative helicity: 511 m²/s²
Significant tornado parameter: 4.0
Supercell composite: 19.6

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 25, 11:42 PM CDT	Severe Thunderstorm Watch	SPC	Colbert, Franklin, Lauderdale, Lawrence, Limestone	7 hr
Apr 26, 2:04 AM CDT	Mesoscale Discussion	SPC	Lawrence, Limestone, Madison, Morgan, Winston	56 min
Apr 25, 7:34 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 33 more	116 min
Apr 25, 9:23 PM CDT	Tornado Watch	SPC	Ashley, Chicot	7 hr
Apr 26, 10:51 AM CDT	Mesoscale Discussion	SPC	Crittenden, Cross, Lee, Mississippi, Phillips, Poinsett and 2 more	54 min
Apr 26, 1:11 PM CDT	Mesoscale Discussion	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 12 more	2 hr
Apr 26, 1:44 PM CDT	Tornado Watch PDS	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 16 more	10 hr
Apr 26, 2:41 PM CDT	Mesoscale Discussion	SPC	Arkansas, Chicot, Craighead, Crittenden, Cross, Desha and 11 more	94 min
Apr 26, 3:02 PM CDT	Tornado Watch PDS	SPC	Arkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 21 more	7 hr
Apr 26, 3:59 PM CDT	Mesoscale Discussion	SPC	Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 12 more	91 min
Apr 26, 5:00 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Cleburne, Conway, Crawford, Faulkner and 19 more	30 min
Apr 26, 5:08 PM CDT	Tornado Watch	SPC	Baxter, Cleburne, Conway, Crawford, Franklin, Fulton and 15 more	5 hr
Apr 26, 6:17 PM CDT	Mesoscale Discussion	SPC	Arkansas, Baxter, Benton, Boone, Bradley, Calhoun and 63 more	118 min
Apr 26, 6:43 PM CDT	Mesoscale Discussion	SPC	Columbia, Lafayette, Little River, Miller, Union	2 hr
Apr 26, 12:26 PM CDT	Mesoscale Discussion	SPC	Champaign, Clark, Douglas, Edgar, Ford, Iroquois and 1 more	94 min
Apr 26, 2:02 PM CDT	Tornado Watch	SPC	Champaign, Clark, Coles, Cumberland, Douglas, Edgar and 2 more	7 hr
Apr 26, 4:38 PM CDT	Mesoscale Discussion	SPC	Clark, Crawford, Edwards, Gallatin, Hamilton, Jasper and 5 more	37 min
Apr 26, 4:50 PM CDT	Tornado Watch	SPC	Gallatin, Saline, Wabash, White	5 hr
Apr 26, 3:53 PM CDT	Mesoscale Discussion	SPC	Carroll, Cass, Elkhart, Fulton, Howard, Jasper and 13 more	67 min
Apr 26, 12:49 PM CDT	Mesoscale Discussion	SPC	Martin	56 min
Apr 25, 9:37 PM CDT	Mesoscale Discussion	SPC	De Soto, Sabine	83 min
Apr 25, 10:47 PM CDT	Tornado Watch	SPC	Allen, Beauregard, Evangeline, Rapides, Sabine, Vernon	5 hr
Apr 26, 1:34 AM CDT	Mesoscale Discussion	SPC	Allen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 1 more	86 min
Apr 26, 1:52 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 7 more	5 hr
Apr 26, 4:56 PM CDT	Tornado Watch	SPC	Beauregard, Bienville, Caldwell, De Soto, Grant, Jackson and 9 more	5 hr

Nearby

Mesoscale Discussions in Mississippi, 2011 Mesoscale Discussions in Tennessee, 2011 Mesoscale Discussions in Kentucky, 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.