Alert archive / Tennessee / Mesoscale Discussions in 2026
Mesoscale Discussion 1939
The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2026, 8:12 PM EDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2026, 8:12 PM EDT (00:12 UTC)
- Expired
- Aug 11, 2026, 10:15 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 568...571
All 39 counties
Bell County, KY, Clinton County, KY, Knox County, KY, McCreary County, KY, Pulaski County, KY, Russell County, KY, Wayne County, KY, Whitley County, KY, Haywood County, NC, Madison County, NC, Mitchell County, NC, Swain County, NC, Yancey County, NC, Anderson County, TN, Blount County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Morgan County, TN, Pickett County, TN, Roane County, TN, Scott County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Washington County, TN, Lee County, VA, Scott County, VA
The radar
The Knoxville radar (KMRX), 33 km from the middle of the area, began a volume at 00:12 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 nearest sounding before it
Nashville Metro, TN (KBNA), launched 00:00Z, 0.2 hours before the alert went out and 263 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
- 3410 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 1244 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -12 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.0
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 |
|---|---|---|---|---|
| Aug 12, 1:52 PM EDT | Mesoscale Discussion | SPC | Anderson, Breckinridge, Bullitt, Carroll, Franklin, Gallatin and 15 more | 113 min |
| Aug 12, 3:24 PM EDT | Severe Thunderstorm Watch | SPC | Anderson, Boyle, Breckinridge, Bullitt, Casey, Daviess and 27 more | 5 hr |
| Aug 12, 5:33 PM EDT | Mesoscale Discussion | SPC | Anderson, Ballard, Barren, Bourbon, Boyle, Breckinridge and 51 more | 117 min |
Nearby
Mesoscale Discussions in Tennessee, 2026Mesoscale Discussions in Kentucky, 2026Mesoscale Discussions in North Carolina, 2026Every mesoscale discussion in 2026
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.