Alert archive / Tennessee / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 499
The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2011, 9:39 AM CDT for 5 states. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 18, 2011, 9:39 AM CDT (14:39 UTC)
- Expired
- Jun 18, 2011, 4:11 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 70 kt
All 75 counties
Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Dunklin County, MO, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Bedford County, TN, Benton County, TN, Carroll County, TN, Chester County, TN, Coffee County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Franklin County, TN, Gibson County, TN, Giles County, TN, Grundy County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Moore County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN
The radar
The Memphis radar (KNQA), 100 km from the middle of the area, began a volume at 14:43 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
- 2%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 10:26 AM CDT | Severe Thunderstorm Warning | MEG | Gibson, Henry, Lake, Obion, Weakley | 64 min |
| Jun 18, 10:57 AM CDT | Severe Thunderstorm Warning | MEG | Carroll, Crockett, Dyer, Gibson, Henry, Lake and 1 more | 63 min |
| Jun 18, 11:42 AM CDT | Severe Thunderstorm Warning | MEG | Carroll, Chester, Decatur, Henderson, Madison | 63 min |
| Jun 18, 11:49 AM CDT | Severe Thunderstorm Warning | OHX | Benton, Humphreys, Perry | 41 min |
| Jun 18, 11:59 AM CDT | Flash Flood Warning | MEG | Carroll, Decatur, Henderson | 5 hr |
| Jun 18, 12:22 PM CDT | Severe Thunderstorm Warning | OHX | Hickman, Humphreys, Lewis, Perry, Wayne | 38 min |
| Jun 18, 12:26 PM CDT | Severe Thunderstorm Warning | MEG | Chester, Decatur, Hardin, McNairy | 34 min |
| Jun 18, 12:47 PM CDT | Severe Thunderstorm Warning | MEG | Mississippi | 22 min |
| Jun 18, 12:54 PM CDT | Severe Thunderstorm Warning | OHX | Hickman, Lawrence, Lewis, Maury, Williamson | 41 min |
| Jun 18, 1:09 PM CDT | Severe Thunderstorm Warning | OHX | Bedford, Coffee | 51 min |
| Jun 18, 1:21 PM CDT | Severe Thunderstorm Warning | OHX | Bedford, Giles, Lawrence, Marshall, Maury | 39 min |
| Jun 18, 1:32 PM CDT | Severe Thunderstorm Warning | HUN | Franklin, Lincoln, Moore | 58 min |
| Jun 18, 1:39 PM CDT | Tornado Warning | OHX | Bedford, Marshall | 36 min |
| Jun 18, 1:55 PM CDT | Severe Thunderstorm Warning | MEG | Fayette, Hardeman | 34 min |
| Jun 18, 1:58 PM CDT | Severe Thunderstorm Warning | OHX | Bedford, Coffee, Marshall | 47 min |
| Jun 18, 2:14 PM CDT | Severe Thunderstorm Warning | OHX | Coffee, Grundy, Warren | 46 min |
| Jun 18, 2:18 PM CDT | Severe Thunderstorm Warning | HUN | Jackson, Madison | 42 min |
| Jun 18, 2:26 PM CDT | Severe Thunderstorm Warning | HUN | Jackson, Madison | 33 min |
| Jun 18, 2:37 PM CDT | Severe Thunderstorm Warning | HUN | DeKalb, Jackson, Madison | 53 min |
| Jun 18, 2:44 PM CDT | Severe Thunderstorm Warning | HUN | Limestone, Madison, Morgan | 25 min |
| Jun 18, 3:28 PM CDT | Severe Thunderstorm Warning | HUN | DeKalb, Jackson | 36 min |
| Jun 18, 3:48 PM CDT | Severe Thunderstorm Warning | HUN | DeKalb | 20 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
Little Rock, AR (KLZK), launched 12:00Z, 2.7 hours before the alert went out and 129 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
- 2509 J/kg
- Mixed-layer CIN
- -233 J/kg
- Mixed-layer LCL
- 941 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 120 m²/s²
- 0-3 km storm-relative helicity
- 178 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 8:38 AM CDT | Mesoscale Discussion | SPC | Blount, Calhoun, Cherokee, Colbert, Cullman, DeKalb and 12 more | 97 min |
| Jun 17, 8:19 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Bates, Benton, Camden, Carroll, Cass and 24 more | 7 hr |
| Jun 17, 11:12 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Cass, Cedar, Henry, Jackson and 3 more | 93 min |
| Jun 18, 2:07 AM CDT | Mesoscale Discussion | SPC | Bates, Benton, Buchanan, Caldwell, Camden, Carroll and 21 more | 53 min |
| Jun 18, 2:44 AM CDT | Severe Thunderstorm Watch | SPC | Audrain, Benton, Boone, Callaway, Camden, Carroll and 40 more | 5 hr |
| Jun 18, 5:39 AM CDT | Mesoscale Discussion | SPC | Audrain, Bollinger, Boone, Callaway, Camden, Cape Girardeau and 36 more | 66 min |
| Jun 18, 3:34 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Cass, Cedar, Dade and 8 more | 116 min |
| Jun 18, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Bates, Benton, Carroll, Cass and 28 more | 10 hr |
| Jun 18, 10:05 AM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bledsoe, Blount, Bradley, Campbell, Carter and 27 more | 9 hr |
| Jun 18, 1:21 PM CDT | Mesoscale Discussion | SPC | Bradley, Hamilton, Polk | 84 min |
Nearby
Severe Thunderstorm Watches in Tennessee, 2011Severe Thunderstorm Watches in Mississippi, 2011Severe Thunderstorm Watches in Alabama, 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.