Alert archive / Tennessee / Mesoscale Discussions in 2017

Mesoscale Discussion 824

May 24, 20175 states

The Storm Prediction Center issued this mesoscale discussion at May 24, 2017, 6:41 AM CDT for 5 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 24, 2017, 6:41 AM CDT (11:41 UTC)
Expired: May 24, 2017, 9:15 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 67 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Jefferson County, AL, Marshall County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Murray County, GA, Pickens County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Bell County, KY, Clay County, KY, Harlan County, KY, Jackson County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, McCreary County, KY, Owsley County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Cherokee County, NC, Graham County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Claiborne County, TN, Cumberland County, TN, Fentress County, TN, Grainger County, TN, Hamilton County, TN, Hancock County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Union County, TN

The radar

The Northeast Alabama radar (KHTX), 88 km from the middle of the area, began a volume at 11:40 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 262May 24, 9:00 AM CDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 11.7 hours before the alert went out and 160 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: 2 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1676 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 23, 7:12 PM CDT	Mesoscale Discussion	SPC	Chambers, Chilton, Clay, Cleburne, Coosa, Randolph and 1 more	93 min
May 23, 7:46 PM CDT	Mesoscale Discussion	SPC	Appling, Bacon, Brantley, Bryan, Bulloch, Candler and 12 more	89 min
May 24, 5:56 AM CDT	Tornado Watch	SPC	Brooks, Decatur, Grady, Lowndes, Seminole, Thomas	8 hr
May 24, 7:29 AM CDT	Mesoscale Discussion	SPC	Appling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 83 more	3 hr
May 24, 9:04 AM CDT	Tornado Watch	SPC	Banks, Barrow, Bartow, Carroll, Catoosa, Chattooga and 50 more	11 hr
May 24, 9:26 AM CDT	Mesoscale Discussion	SPC	Decatur, Grady, Seminole	94 min
May 24, 10:03 AM CDT	Tornado Watch	SPC	Appling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 96 more	10 hr
May 24, 1:10 PM CDT	Mesoscale Discussion	SPC	Appling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 99 more	95 min
May 24, 2:02 PM CDT	Mesoscale Discussion	SPC	Banks, Barrow, Bartow, Carroll, Cherokee, Clarke and 43 more	88 min
May 24, 4:25 PM CDT	Mesoscale Discussion	SPC	Appling, Atkinson, Bacon, Baldwin, Banks, Barrow and 87 more	65 min
May 24, 10:47 AM CDT	Mesoscale Discussion	SPC	Boone, Campbell, Kenton	58 min
May 24, 11:47 AM CDT	Mesoscale Discussion	SPC	Adair, Allen, Barren, Casey, Clinton, Cumberland and 11 more	58 min
May 24, 12:19 PM CDT	Tornado Watch	SPC	Adair, Anderson, Bath, Bell, Bourbon, Boyle and 51 more	7 hr
May 24, 2:50 PM CDT	Mesoscale Discussion	SPC	Adair, Anderson, Bath, Bell, Bourbon, Boyle and 53 more	55 min
May 24, 5:51 PM CDT	Mesoscale Discussion	SPC	Carter, Elliott, Floyd, Johnson, Knott, Lawrence and 6 more	24 min
May 24, 2:13 PM CDT	Mesoscale Discussion	SPC	Alamance, Alleghany, Bladen, Brunswick, Caswell, Chatham and 37 more	2 hr
May 24, 2:46 PM CDT	Tornado Watch	SPC	Alamance, Alleghany, Anson, Ashe, Beaufort, Bladen and 52 more	6 hr
May 24, 5:59 PM CDT	Mesoscale Discussion	SPC	Bertie, Camden, Chowan, Currituck, Edgecombe, Franklin and 15 more	91 min

Nearby

Mesoscale Discussions in Tennessee, 2017 Mesoscale Discussions in Georgia, 2017 Mesoscale Discussions in Kentucky, 2017 Every mesoscale discussion in 2017

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.