Alert archive / Missouri / Mesoscale Discussions in 2005

Mesoscale Discussion 641

April 21, 20055 states

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 8:19 PM CDT for 5 states. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Apr 21, 2005, 8:19 PM CDT (01:19 UTC)
Expired: Apr 21, 2005, 9:45 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

All 32 counties

Clay County, AR, Greene County, AR, Lawrence County, AR, Randolph County, AR, Alexander County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Hickman County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Dyer County, TN, Lake County, TN, Obion County, TN

The radar

The Paducah radar (KPAH), 99 km from the middle of the area, began a volume at 01:20 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 184Apr 21, 11:50 PM CDT

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 1.3 hours before the alert went out and 220 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: 1345 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 1563 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

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 21, 10:16 PM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Conway and 21 more	119 min
Apr 21, 11:50 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Clay, Cleburne, Conway, Crawford and 25 more	6 hr
Apr 22, 3:09 AM CDT	Mesoscale Discussion	SPC	Clark, Clay, Cleburne, Conway, Craighead, Cross and 23 more	66 min
Apr 21, 8:03 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clinton, Franklin, Hamilton, Jefferson and 10 more	87 min
Apr 21, 10:25 PM CDT	Mesoscale Discussion	SPC	Calhoun, Jersey, Madison, Monroe, Randolph, Saint Clair	65 min
Apr 22, 10:56 AM CDT	Mesoscale Discussion	SPC	Christian, Clark, Clay, Coles, Crawford, Cumberland and 15 more	94 min
Apr 22, 1:30 PM CDT	Severe Thunderstorm Watch	SPC	Champaign, Clark, Clay, Coles, Crawford, Cumberland and 19 more	8 hr
Apr 22, 5:36 AM CDT	Mesoscale Discussion	SPC	Allen, Logan, Simpson, Todd	84 min
Apr 22, 3:17 PM CDT	Mesoscale Discussion	SPC	Anderson, Bath, Boone, Bourbon, Boyle, Bracken and 47 more	88 min
Apr 22, 3:50 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bath, Bell, Boone, Bourbon, Boyd and 65 more	7 hr
Apr 22, 5:11 PM CDT	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Boone and 81 more	94 min
Apr 21, 7:47 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Camden, Cedar, Christian, Dade and 22 more	88 min
Apr 21, 9:50 PM CDT	Mesoscale Discussion	SPC	Caldwell, Carroll, Cass, Clay, Clinton, Daviess and 8 more	55 min
Apr 21, 9:23 PM CDT	Mesoscale Discussion	SPC	Bedford, Benton, Cheatham, Davidson, Decatur, Dickson and 18 more	97 min
Apr 22, 11:18 AM CDT	Mesoscale Discussion	SPC	Blount, Sevier	117 min
Apr 22, 2:49 PM CDT	Mesoscale Discussion	SPC	Bedford, Benton, Cannon, Carroll, Cheatham, Coffee and 27 more	86 min
Apr 22, 3:35 PM CDT	Severe Thunderstorm Watch	SPC	Bedford, Benton, Cannon, Cheatham, Coffee, Davidson and 23 more	5 hr
Apr 22, 5:17 PM CDT	Mesoscale Discussion	SPC	Anderson, Bledsoe, Blount, Bradley, Campbell, Claiborne and 23 more	58 min
Apr 22, 5:40 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bledsoe, Blount, Bradley, Campbell, Clay and 24 more	5 hr
Apr 22, 6:40 PM CDT	Mesoscale Discussion	SPC	Anderson, Bedford, Bledsoe, Bradley, Campbell, Cannon and 30 more	95 min

Nearby

Mesoscale Discussions in Missouri, 2005 Mesoscale Discussions in Illinois, 2005 Mesoscale Discussions in Kentucky, 2005 Every mesoscale discussion in 2005

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.