Alert archive / Georgia / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 18
The Storm Prediction Center issued this severe thunderstorm watch at Feb 24, 2011, 11:59 PM EST for 5 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 24, 2011, 11:59 PM EST (04:59 UTC)
- Expired
- Feb 25, 2011, 5:00 AM EST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 79 counties
Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Hall County, GA, Haralson County, GA, Heard County, GA, Lumpkin County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Towns County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Bell County, KY, Breathitt County, KY, Clay County, KY, Harlan County, KY, Jackson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Owsley County, KY, Perry County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Cherokee County, NC, Clay County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Claiborne County, TN, Grainger County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Union County, TN, Lee County, VA
The radar
The Knoxville radar (KMRX), 100 km from the middle of the area, began a volume at 04:59 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
- 60%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
26 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 25, 12:23 AM EST | Severe Thunderstorm Warning | JKL | Jackson, Laurel, McCreary, Pulaski, Rockcastle, Wayne and 1 more | 52 min |
| Feb 25, 12:27 AM EST | Severe Thunderstorm Warning | MRX | Campbell, Morgan, Scott | 63 min |
| Feb 25, 12:38 AM EST | Flash Flood Warning | JKL | Jackson, Laurel, McCreary, Pulaski, Rockcastle, Wayne and 1 more | 6 hr |
| Feb 25, 12:47 AM EST | Severe Thunderstorm Warning | MRX | Bledsoe, Morgan, Sequatchie | 28 min |
| Feb 25, 1:04 AM EST | Tornado Warning | MRX | Marion | 41 min |
| Feb 25, 1:12 AM EST | Severe Thunderstorm Warning | FFC | Catoosa, Chattooga, Dade, Floyd, Walker | 63 min |
| Feb 25, 1:14 AM EST | Severe Thunderstorm Warning | MRX | Anderson, Campbell, Claiborne, Morgan, Roane, Scott and 1 more | 61 min |
| Feb 25, 1:16 AM EST | Severe Thunderstorm Warning | MRX | Bledsoe, Hamilton, Meigs, Rhea, Sequatchie | 29 min |
| Feb 25, 1:25 AM EST | Severe Thunderstorm Warning | JKL | Breathitt, Lee, Owsley, Perry | 35 min |
| Feb 25, 1:31 AM EST | Severe Thunderstorm Warning | MRX | Hamilton, Marion | 44 min |
| Feb 25, 1:48 AM EST | Severe Thunderstorm Warning | FFC | Bartow, Floyd, Gordon, Murray, Whitfield | 57 min |
| Feb 25, 1:50 AM EST | Severe Thunderstorm Warning | MRX | Anderson, Blount, Claiborne, Grainger, Hancock, Jefferson and 4 more | 40 min |
| Feb 25, 1:51 AM EST | Severe Thunderstorm Warning | FFC | Carroll, Douglas, Haralson, Paulding, Polk | 54 min |
| Feb 25, 1:51 AM EST | Flash Flood Warning | JKL | Bell, Harlan, Knox | 5 hr |
| Feb 25, 1:52 AM EST | Severe Thunderstorm Warning | MRX | Bledsoe, Hamilton, Meigs, Rhea | 23 min |
| Feb 25, 2:03 AM EST | Severe Thunderstorm Warning | MRX | Bradley, Hamilton, Meigs | 27 min |
| Feb 25, 2:15 AM EST | Severe Thunderstorm Warning | MRX | Loudon, McMinn, Monroe | 45 min |
| Feb 25, 2:22 AM EST | Severe Thunderstorm Warning | MRX | Blount, Cocke, Grainger, Greene, Hamblen, Hancock and 4 more | 42 min |
| Feb 25, 2:23 AM EST | Severe Thunderstorm Warning | MRX | Polk | 37 min |
| Feb 25, 2:25 AM EST | Severe Thunderstorm Warning | FFC | Cherokee, Fannin, Gilmer, Pickens | 54 min |
| Feb 25, 2:25 AM EST | Severe Thunderstorm Warning | MRX | Lee, Scott, Wise, City of Norton | 50 min |
| Feb 25, 2:36 AM EST | Severe Thunderstorm Warning | FFC | Carroll, Coweta, Heard, Troup | 54 min |
| Feb 25, 2:37 AM EST | Severe Thunderstorm Warning | MRX | McMinn, Monroe, Polk | 38 min |
| Feb 25, 2:43 AM EST | Severe Thunderstorm Warning | FFC | Carroll, Cobb, Douglas, Fulton, Hall | 62 min |
| Feb 25, 2:48 AM EST | Severe Thunderstorm Warning | FFC | Carroll, Haralson, Paulding | 27 min |
| Feb 25, 2:54 AM EST | Severe Thunderstorm Warning | MRX | Cherokee, Clay | 36 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, 5.0 hours before the alert went out and 194 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
- 17 J/kg
- Mixed-layer CIN
- -79 J/kg
- Mixed-layer LCL
- 793 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 538 m²/s²
- 0-3 km storm-relative helicity
- 629 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 24, 9:11 PM EST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 4 more | 64 min |
| Feb 24, 9:30 PM EST | Tornado Watch | SPC | Bibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 27 more | 6 hr |
| Feb 24, 11:38 PM EST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 4 more | 97 min |
| Feb 25, 2:35 AM EST | Mesoscale Discussion | SPC | Autauga, Chambers, Clay, Cleburne, Coosa, Elmore and 4 more | 55 min |
| Feb 24, 8:22 PM EST | Mesoscale Discussion | SPC | Adair, Allen, Barren, Butler, Caldwell, Calloway and 32 more | 83 min |
| Feb 24, 8:41 PM EST | Tornado Watch | SPC | Adair, Allen, Barren, Boyle, Butler, Casey and 17 more | 5 hr |
| Feb 25, 1:48 AM EST | Mesoscale Discussion | SPC | Bell, Floyd, Harlan, Johnson, Knott, Lawrence and 6 more | 27 min |
| Feb 25, 11:36 AM EST | Mesoscale Discussion | SPC | Accomack, Caroline, Essex, Gloucester, Hanover, King and Queen and 9 more | 84 min |
| Feb 25, 12:19 PM EST | Severe Thunderstorm Watch | SPC | Arlington, Fairfax, King George, Prince William, Spotsylvania, Stafford and 4 more | 3 hr |
| Feb 25, 2:40 PM EST | Mesoscale Discussion | SPC | Arlington, King George, Stafford, City of Alexandria, City of Falls Church, City of Fredericksburg | 65 min |
Nearby
Severe Thunderstorm Watches in Georgia, 2011Severe Thunderstorm Watches in Tennessee, 2011Severe Thunderstorm Watches in Kentucky, 2011Every severe thunderstorm watch in 2011
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.