Alert archive / Tennessee / Mesoscale Discussions in 2012
Mesoscale Discussion 1861
The Storm Prediction Center issued this mesoscale discussion at Sep 2, 2012, 2:20 PM CDT for 4 states. It was in force for 115 min.
The area
The outline as issued.
The facts
- Issued
- Sep 2, 2012, 2:20 PM CDT (19:20 UTC)
- Expired
- Sep 2, 2012, 4:15 PM CDT
- In force
- 115 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 66 counties
Lauderdale County, AL, Limestone County, AL, Adair County, KY, Allen County, KY, Barren County, KY, Boyle County, KY, Casey County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Green County, KY, Hart County, KY, Larue County, KY, Marion County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Nelson County, KY, Russell County, KY, Simpson County, KY, Taylor County, KY, Warren County, KY, Washington County, KY, Alcorn County, MS, Benton County, MS, Marshall County, MS, Tippah County, MS, Tishomingo County, MS, Bedford County, TN, Cannon County, TN, Cheatham County, TN, Chester County, TN, Clay County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fayette County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Macon County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Moore County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Wayne County, TN, Williamson County, TN, Wilson County, TN
The radar
The Nashville radar (KOHX), 51 km from the middle of the area, began a volume at 19:24 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, 7.3 hours before the alert went out and 47 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
- 257 J/kg
- Mixed-layer CIN
- -12 J/kg
- Mixed-layer LCL
- 627 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 87 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 2:49 PM CDT | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 7 hr |
| Sep 2, 3:42 PM CDT | Tornado Watch | SPC | Fayette, Lamar, Marion, Walker, Winston | 7 hr |
| Sep 2, 5:13 PM CDT | Mesoscale Discussion | SPC | Bibb, Calhoun, Cherokee, Clay, Cleburne, Etowah and 5 more | 62 min |
| Sep 2, 5:33 PM CDT | Severe Thunderstorm Watch | SPC | Blount, Calhoun, Cherokee, Cleburne, Etowah, Jefferson and 1 more | 5 hr |
| Sep 2, 6:35 PM CDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lauderdale, Lawrence, Limestone, Madison and 1 more | 85 min |
| Sep 1, 7:56 PM CDT | Mesoscale Discussion | SPC | Caldwell, Calloway, Crittenden, Graves, Henderson, Hopkins and 8 more | 94 min |
| Sep 1, 9:37 PM CDT | Mesoscale Discussion | SPC | Caldwell, Christian, Henderson, Hopkins, McLean, Todd and 2 more | 23 min |
| Sep 1, 7:08 PM CDT | Severe Thunderstorm Watch | SPC | Alcorn, Benton, Coahoma, Lafayette, Marshall, Panola and 9 more | 6 hr |
| Sep 1, 9:59 PM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Bolivar, Coahoma, Lafayette, Marshall and 6 more | 91 min |
Nearby
Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Mississippi, 2012Every mesoscale discussion in 2012
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.