Alert archive / Tennessee / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 498
The Storm Prediction Center issued this severe thunderstorm watch at Jul 19, 2012, 8:35 PM EDT for 35 counties in Tennessee. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 19, 2012, 8:35 PM EDT (00:35 UTC)
- Expired
- Jul 20, 2012, 12:20 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 35 counties
Anderson County, TN, Campbell County, TN, Cannon County, TN, Cheatham County, TN, Claiborne County, TN, Clay County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Grainger County, TN, Hancock County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Knox County, TN, Macon County, TN, Montgomery County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Nashville radar (KOHX), 46 km from the middle of the area, began a volume at 00:35 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
18 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 8:55 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Montgomery, Robertson | 35 min |
| Jul 19, 9:02 PM EDT | Severe Thunderstorm Warning | MRX | Claiborne, Union | 43 min |
| Jul 19, 9:27 PM EDT | Severe Thunderstorm Warning | OHX | Davidson, Robertson, Sumner | 33 min |
| Jul 19, 9:28 PM EDT | Severe Thunderstorm Warning | MRX | Campbell | 47 min |
| Jul 19, 9:51 PM EDT | Severe Thunderstorm Warning | OHX | Clay, Jackson, Macon, Overton, Smith | 54 min |
| Jul 19, 9:56 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Robertson, Sumner | 34 min |
| Jul 19, 10:00 PM EDT | Severe Thunderstorm Warning | OHX | Robertson, Sumner, Wilson | 15 min |
| Jul 19, 10:09 PM EDT | Severe Thunderstorm Warning | MRX | Campbell, Claiborne, Union | 51 min |
| Jul 19, 10:23 PM EDT | Severe Thunderstorm Warning | OHX | Macon, Smith, Sumner, Trousdale, Wilson | 37 min |
| Jul 19, 10:29 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Sumner, Wilson | 31 min |
| Jul 19, 10:36 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Dickson | 24 min |
| Jul 19, 10:46 PM EDT | Severe Thunderstorm Warning | OHX | Clay, Jackson, Macon, Overton, Pickett, Smith | 29 min |
| Jul 19, 10:57 PM EDT | Severe Thunderstorm Warning | MRX | Campbell, Claiborne, Scott | 51 min |
| Jul 19, 10:57 PM EDT | Severe Thunderstorm Warning | OHX | Macon, Smith, Sumner, Trousdale, Wilson | 33 min |
| Jul 19, 11:00 PM EDT | Severe Thunderstorm Warning | OHX | Dickson, Houston, Montgomery, Stewart | 45 min |
| Jul 19, 11:01 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Dickson, Rutherford, Sumner, Williamson and 1 more | 29 min |
| Jul 19, 11:13 PM EDT | Flash Flood Warning | MRX | Campbell, Claiborne, Union | 3 hr |
| Jul 19, 11:41 PM EDT | Severe Thunderstorm Warning | OHX | Davidson, Rutherford, Williamson | 19 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 00:00Z, 0.6 hours before the alert went out and 53 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
- 2853 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 1475 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- 50 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 11:26 PM EDT | Mesoscale Discussion | SPC | Anderson, Benton, Campbell, Cannon, Cheatham, Claiborne and 31 more | 64 min |
Nearby
Severe Thunderstorm Watches in Tennessee, 2012Every severe thunderstorm watch 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.