Alert archive / Alabama / Tornado Watches in 2009
Tornado Watch 17
The Storm Prediction Center issued this tornado watch at Feb 11, 2009, 11:10 AM CST for 25 counties in Alabama; 18 counties in Georgia; 12 counties in Tennessee. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 11, 2009, 11:10 AM CST (17:10 UTC)
- Expired
- Feb 11, 2009, 5:00 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 55 counties
Bibb County, AL, Blount County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Jefferson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Dade County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Heard County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Bledsoe County, TN, Bradley County, TN, Franklin County, TN, Hamilton County, TN, Lincoln County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Moore County, TN, Polk County, TN, Rhea County, TN, Sequatchie County, TN
The radar
The Northeast Alabama radar (KHTX), 61 km from the middle of the area, began a volume at 17:12 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 11, 11:11 AM CST | Severe Thunderstorm Warning | BMX | Marion, Winston | 34 min |
| Feb 11, 11:27 AM CST | Severe Thunderstorm Warning | HUN | Lauderdale, Lawrence, Limestone, Morgan | 48 min |
| Feb 11, 11:58 AM CST | Severe Thunderstorm Warning | HUN | Lincoln, Moore | 47 min |
| Feb 11, 12:11 PM CST | Severe Thunderstorm Warning | HUN | Limestone, Madison, Morgan | 49 min |
| Feb 11, 12:41 PM CST | Severe Thunderstorm Warning | HUN | Franklin, Lincoln, Moore | 49 min |
| Feb 11, 12:54 PM CST | Severe Thunderstorm Warning | HUN | Jackson, Madison, Marshall, Morgan | 51 min |
| Feb 11, 1:04 PM CST | Severe Thunderstorm Warning | BMX | Blount, Jefferson, St. Clair | 26 min |
| Feb 11, 1:18 PM CST | Severe Thunderstorm Warning | MRX | Bledsoe, Marion, Sequatchie | 72 min |
| Feb 11, 1:29 PM CST | Severe Thunderstorm Warning | HUN | Franklin | 16 min |
| Feb 11, 1:41 PM CST | Severe Thunderstorm Warning | BMX | Blount, Etowah, St. Clair | 34 min |
| Feb 11, 1:51 PM CST | Severe Thunderstorm Warning | FFC | Chattooga, Dade, Walker | 54 min |
| Feb 11, 1:59 PM CST | Severe Thunderstorm Warning | MRX | Hamilton, Meigs, Rhea | 61 min |
| Feb 11, 2:00 PM CST | Severe Thunderstorm Warning | HUN | DeKalb | 30 min |
| Feb 11, 2:16 PM CST | Severe Thunderstorm Warning | HUN | DeKalb, Jackson | 29 min |
| Feb 11, 2:25 PM CST | Severe Thunderstorm Warning | FFC | Catoosa, Chattooga, Floyd, Gordon, Walker, Whitfield | 65 min |
| Feb 11, 2:44 PM CST | Severe Thunderstorm Warning | MRX | Bradley, Loudon, McMinn, Monroe, Polk | 55 min |
| Feb 11, 3:02 PM CST | Severe Thunderstorm Warning | FFC | Bartow, Fannin, Gilmer, Gordon, Murray, Pickens and 2 more | 58 min |
| Feb 11, 3:09 PM CST | Severe Thunderstorm Warning | BMX | Cherokee | 25 min |
| Feb 11, 3:26 PM CST | Severe Thunderstorm Warning | MRX | Monroe, Polk | 64 min |
| Feb 11, 3:56 PM CST | Severe Thunderstorm Warning | FFC | Bartow, Cherokee, Dawson, Fannin, Gilmer, Lumpkin and 3 more | 64 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
Birmingham, AL (KBMX), launched 12:00Z, 5.2 hours before the alert went out and 145 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
- 42 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 539 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 361 m²/s²
- 0-3 km storm-relative helicity
- 365 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 |
|---|---|---|---|---|
| Feb 11, 9:36 AM CST | Mesoscale Discussion | SPC | Autauga, Baldwin, Barbour, Bullock, Butler, Chambers and 26 more | 84 min |
| Feb 11, 10:02 AM CST | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 3 more | 88 min |
| Feb 11, 1:29 PM CST | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Chambers, Cherokee, Chilton and 13 more | 2 hr |
| Feb 11, 3:08 PM CST | Severe Thunderstorm Watch | SPC | Banks, Barrow, Butts, Clarke, Clayton, Cobb and 34 more | 5 hr |
| Feb 10, 11:45 PM CST | Tornado Watch | SPC | Dyer, Lake, Lauderdale, Obion, Shelby, Tipton | 6 hr |
| Feb 11, 2:30 AM CST | Mesoscale Discussion | SPC | Crockett, Dyer, Fayette, Gibson, Haywood, Lake and 5 more | 90 min |
| Feb 11, 5:26 AM CST | Mesoscale Discussion | SPC | Dyer, Lake, Lauderdale, Obion, Tipton | 64 min |
| Feb 11, 10:38 AM CST | Tornado Watch | SPC | Bedford, Cannon, Cheatham, Clay, Coffee, Cumberland and 21 more | 6 hr |
| Feb 11, 12:35 PM CST | Mesoscale Discussion | SPC | Anderson, Bedford, Bledsoe, Blount, Campbell, Cannon and 39 more | 85 min |
| Feb 11, 12:59 PM CST | Tornado Watch | SPC | Anderson, Blount, Campbell, Carter, Claiborne, Cocke and 18 more | 7 hr |
| Feb 11, 3:34 PM CST | Mesoscale Discussion | SPC | Blount, Carter, Claiborne, Cocke, Grainger, Greene and 12 more | 86 min |
Nearby
Tornado Watches in Alabama, 2009Tornado Watches in Georgia, 2009Tornado Watches in Tennessee, 2009Every tornado watch in 2009
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.