Alert archive / Tennessee / Mesoscale Discussions in 2018
Mesoscale Discussion 1108
The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2018, 5:54 PM CDT for 6 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 20, 2018, 5:54 PM CDT (22:54 UTC)
- Expired
- Jul 20, 2018, 8:30 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 95%
All 125 counties
Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Winston County, AL, Crittenden County, AR, Lee County, AR, Phillips County, AR, St. Francis County, AR, Dade County, GA, Allen County, KY, Barren County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Christian County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Graves County, KY, Hickman County, KY, Hopkins County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, Metcalfe County, KY, Monroe County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Warren County, KY, Alcorn County, MS, Benton County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Bedford County, TN, Benton County, TN, Bledsoe County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Clay County, TN, Coffee County, TN, Crockett County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Fentress County, TN, Franklin County, TN, Gibson County, TN, Giles County, TN, Grundy 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, Jackson County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Macon County, TN, Madison County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Moore County, TN, Obion County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Robertson County, TN, Rutherford County, TN, Sequatchie County, TN, Shelby County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Tipton County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, Weakley County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Ft Campbell radar (KHPX), 131 km from the middle of the area, began a volume at 22:57 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, 10.9 hours before the alert went out and 128 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.
- Mixed-layer CAPE
- 918 J/kg
- Mixed-layer CIN
- -46 J/kg
- Mixed-layer LCL
- 766 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 123 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 5.7
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 6:22 PM CDT | Tornado Watch | SPC | Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more | 8 hr |
| Jul 19, 7:07 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Boone, Carroll, Cleburne, Fulton, Independence and 10 more | 3 hr |
| Jul 19, 8:02 PM CDT | Mesoscale Discussion | SPC | Arkansas, Baxter, Clark, Cleburne, Cleveland, Conway and 40 more | 118 min |
| Jul 19, 8:54 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Clay, Cleveland and 35 more | 114 min |
| Jul 19, 11:21 PM CDT | Mesoscale Discussion | SPC | Chicot, Desha, Phillips | 114 min |
| Jul 20, 9:25 AM CDT | Mesoscale Discussion | SPC | Arkansas, Cleburne, Crittenden, Cross, Faulkner, Independence and 13 more | 2 hr |
| Jul 20, 12:58 PM CDT | Mesoscale Discussion | SPC | Clay | 62 min |
| Jul 20, 3:46 PM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Fulton, Izard, Marion, Randolph and 2 more | 59 min |
| Jul 20, 3:58 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Clay, Craighead, Cross, Fulton, Greene and 8 more | 6 hr |
| Jul 20, 11:17 AM CDT | Mesoscale Discussion | SPC | Butler, Caldwell, Calloway, Christian, Crittenden, Daviess and 11 more | 58 min |
| Jul 20, 12:19 PM CDT | Mesoscale Discussion | SPC | Adair, Anderson, Barren, Boone, Boyle, Breckinridge and 33 more | 56 min |
| Jul 20, 12:37 PM CDT | Tornado Watch | SPC | Adair, Allen, Anderson, Barren, Boone, Bourbon and 54 more | 7 hr |
| Jul 20, 2:43 PM CDT | Mesoscale Discussion | SPC | Adair, Anderson, Bath, Boone, Bourbon, Boyle and 60 more | 62 min |
| Jul 20, 3:16 PM CDT | Severe Thunderstorm Watch | SPC | Bath, Bell, Boyd, Breathitt, Carter, Clay and 31 more | 6 hr |
| Jul 20, 5:37 PM CDT | Mesoscale Discussion | SPC | Adair, Allen, Anderson, Barren, Boone, Bourbon and 57 more | 53 min |
| Jul 20, 6:24 PM CDT | Mesoscale Discussion | SPC | Bath, Bell, Boyd, Breathitt, Carter, Clark and 33 more | 96 min |
| Jul 20, 1:23 PM CDT | Mesoscale Discussion | SPC | Attala, Carroll, Choctaw, Clarke, Copiah, Covington and 20 more | 97 min |
| Jul 20, 2:11 PM CDT | Severe Thunderstorm Watch | SPC | Clarke, Covington, Forrest, Hinds, Jasper, Jefferson Davis and 14 more | 3 hr |
Nearby
Mesoscale Discussions in Tennessee, 2018Mesoscale Discussions in Kentucky, 2018Mesoscale Discussions in Mississippi, 2018Every mesoscale discussion in 2018
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.