Alert archive / Tennessee / Mesoscale Discussions in 2013

Mesoscale Discussion 276

March 18, 20135 states

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2013, 12:44 PM CDT for 5 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Mar 18, 2013, 12:44 PM CDT (17:44 UTC)
Expired: Mar 18, 2013, 2:15 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center

All 83 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Walker County, GA, Whitfield County, GA, Clinton County, KY, Alcorn County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Clay County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS, Bedford County, TN, Bledsoe County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Jackson County, TN, Lawrence County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Van Buren County, TN, Warren County, TN, White County, TN

The radar

The Northeast Alabama radar (KHTX), 102 km from the middle of the area, began a volume at 17:46 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.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 5.7 hours before the alert went out and 137 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: 188 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 810 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 376 m²/s²
0-3 km storm-relative helicity: 366 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

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
Mar 18, 7:40 AM CDT	Mesoscale Discussion	SPC	Lauderdale, Limestone	2 hr
Mar 18, 8:09 AM CDT	Severe Thunderstorm Watch	SPC	Colbert, Cullman, DeKalb, Fayette, Franklin, Jackson and 10 more	7 hr
Mar 18, 1:10 PM CDT	Mesoscale Discussion	SPC	Bibb, Blount, Calhoun, Cherokee, Chilton, Cullman and 21 more	65 min
Mar 18, 1:11 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Butler, Chambers, Coffee and 19 more	94 min
Mar 18, 1:31 PM CDT	Severe Thunderstorm Watch	SPC	Bibb, Blount, Calhoun, Cherokee, Cleburne, Colbert and 28 more	8 hr
Mar 18, 3:16 PM CDT	Tornado Watch	SPC	Autauga, Barbour, Bullock, Chambers, Chilton, Clay and 10 more	6 hr
Mar 18, 4:28 PM CDT	Mesoscale Discussion	SPC	Butler, Choctaw, Clarke, Conecuh, Covington, Monroe and 2 more	32 min
Mar 18, 4:34 PM CDT	Severe Thunderstorm Watch	SPC	Butler, Choctaw, Clarke, Conecuh, Crenshaw, Monroe and 2 more	5 hr
Mar 18, 4:57 PM CDT	Mesoscale Discussion	SPC	Barbour, Bullock, Calhoun, Chambers, Clay, Cleburne and 11 more	2 hr
Mar 18, 6:29 PM CDT	Severe Thunderstorm Watch	SPC	Appling, Bacon, Bryan, Bulloch, Burke, Candler and 24 more	6 hr
Mar 17, 10:58 PM CDT	Mesoscale Discussion	SPC	Coahoma, DeSoto, Tate, Tunica	3 hr
Mar 18, 7:24 AM CDT	Mesoscale Discussion	SPC	Bolivar, Coahoma, Tunica	3 hr

Nearby

Mesoscale Discussions in Tennessee, 2013 Mesoscale Discussions in Alabama, 2013 Mesoscale Discussions in Mississippi, 2013 Every mesoscale discussion in 2013

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.