Alert archive / Mississippi / Tornado Watches in 2009
Tornado Watch 797
The Storm Prediction Center issued this tornado watch at Dec 8, 2009, 5:48 PM CST for 4 counties in Alabama; 15 counties in Mississippi; 6 counties in Tennessee. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 8, 2009, 5:48 PM CST (23:48 UTC)
- Expired
- Dec 8, 2009, 11:48 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 25 counties
Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS, Giles County, TN, Hardeman County, TN, Hardin County, TN, Lawrence County, TN, McNairy County, TN, Wayne County, TN
The radar
The Columbus AFB radar (KGWX), 94 km from the middle of the area, began a volume at 23:52 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
- 30%
- Ten or more severe wind reports
- 30%
- 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
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 8, 6:19 PM CST | Severe Thunderstorm Warning | MEG | Lafayette, Panola, Tallahatchie, Yalobusha | 26 min |
| Dec 8, 6:31 PM CST | Severe Thunderstorm Warning | MEG | Benton, Lafayette, Marshall, Union | 18 min |
| Dec 8, 6:46 PM CST | Flash Flood Warning | HUN | Franklin, Lawrence | 6 hr |
| Dec 8, 8:23 PM CST | Flash Flood Warning | HUN | Cullman, Lawrence, Limestone, Madison, Morgan | 4 hr |
| Dec 8, 9:31 PM CST | Flash Flood Warning | HUN | Lawrence, Limestone, Madison, Morgan | 3 hr |
| Dec 8, 10:51 PM CST | Severe Thunderstorm Warning | MEG | Chickasaw, Monroe | 39 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, 11.8 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 414 m above ground
- 0-6 km bulk shear
- 80 kt
- 0-1 km storm-relative helicity
- 435 m²/s²
- 0-3 km storm-relative helicity
- 364 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 |
|---|---|---|---|---|
| Dec 8, 5:12 PM CST | Mesoscale Discussion | SPC | Colbert, Franklin, Lamar, Lauderdale, Marion | 63 min |
| Dec 8, 5:55 PM CST | Mesoscale Discussion | SPC | Bibb, Choctaw, Fayette, Greene, Hale, Jefferson and 6 more | 95 min |
| Dec 8, 9:43 AM CST | Mesoscale Discussion | SPC | Bolivar, Carroll, Coahoma, Holmes, Humphreys, Issaquena and 9 more | 2 hr |
| Dec 8, 12:12 PM CST | Mesoscale Discussion | SPC | Adams, Amite, Claiborne, Copiah, Covington, Franklin and 14 more | 93 min |
| Dec 8, 1:25 PM CST | Tornado Watch | SPC | Adams, Amite, Attala, Bolivar, Carroll, Choctaw and 28 more | 8 hr |
Nearby
Tornado Watches in Mississippi, 2009Tornado Watches in Tennessee, 2009Tornado Watches in Alabama, 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.