Alert archive / Tennessee / Mesoscale Discussions in 2018
Mesoscale Discussion 917
The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 10:22 AM CDT for 4 states. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Jun 28, 2018, 10:22 AM CDT (15:22 UTC)
- Expired
- Jun 28, 2018, 12:15 PM CDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 70 counties
Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Cobb County, GA, Dade County, GA, Dawson County, GA, Douglas County, GA, Floyd County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Calloway County, KY, Graves County, KY, Bedford County, TN, Benton County, TN, Bradley County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Hardin County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Moore County, TN, Perry County, TN, Rutherford County, TN, Sequatchie County, TN, Stewart County, TN, Warren County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN
The radar
The Northeast Alabama radar (KHTX), 23 km from the middle of the area, began a volume at 15:24 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, 3.4 hours before the alert went out and 134 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
- 2274 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 1063 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 195 m²/s²
- 0-3 km storm-relative helicity
- 251 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 11.7
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 |
|---|---|---|---|---|
| Jun 28, 10:46 AM CDT | Severe Thunderstorm Watch | SPC | Autauga, Barbour, Blount, Bullock, Calhoun, Chambers and 32 more | 8 hr |
| Jun 28, 1:07 PM CDT | Mesoscale Discussion | SPC | Autauga, Barbour, Bibb, Blount, Bullock, Butler and 44 more | 113 min |
| Jun 28, 4:34 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Butler, Choctaw, Clarke, Coffee and 21 more | 86 min |
| Jun 28, 4:59 PM CDT | Severe Thunderstorm Watch | SPC | Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 18 more | 7 hr |
| Jun 28, 6:22 PM CDT | Mesoscale Discussion | SPC | Brooks, Camden, Charlton, Clinch, Decatur, Echols and 5 more | 83 min |
| Jun 28, 2:00 AM CDT | Mesoscale Discussion | SPC | Adair, Allen, Ballard, Barren, Butler, Caldwell and 31 more | 3 hr |
| Jun 28, 8:43 AM CDT | Mesoscale Discussion | SPC | Ballard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 10 more | 62 min |
| Jun 28, 5:33 PM CDT | Severe Thunderstorm Watch | SPC | Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more | 7 hr |
Nearby
Mesoscale Discussions in Tennessee, 2018Mesoscale Discussions in Georgia, 2018Mesoscale Discussions in Alabama, 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.