Alert archive / Louisiana / Tornado Watches in 2009
Tornado Watch 15
The Storm Prediction Center issued this tornado watch at Feb 11, 2009, 1:04 AM CST for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 11, 2009, 1:04 AM CST (07:04 UTC)
- Expired
- Feb 11, 2009, 6:04 AM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 47 counties
Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Desha County, AR, Drew County, AR, Lincoln County, AR, Union County, AR, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bolivar County, MS, Issaquena County, MS, Sharkey County, MS, Sunflower County, MS, Washington County, MS, Hardin County, TX, Jasper County, TX, Newton County, TX, Sabine County, TX, Tyler County, TX
The radar
The Shreveport radar (KSHV), 124 km from the middle of the area, began a volume at 07:05 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 11, 1:26 AM CST | Severe Thunderstorm Warning | SHV | Sabine | 49 min |
| Feb 11, 1:34 AM CST | Severe Thunderstorm Warning | SHV | Columbia, Union | 41 min |
| Feb 11, 1:45 AM CST | Severe Thunderstorm Warning | LCH | Jasper, Newton, Tyler | 45 min |
| Feb 11, 2:10 AM CST | Severe Thunderstorm Warning | SHV | Union | 50 min |
| Feb 11, 2:14 AM CST | Severe Thunderstorm Warning | SHV | Natchitoches, Red River, Sabine | 46 min |
| Feb 11, 2:53 AM CST | Severe Thunderstorm Warning | SHV | Union | 52 min |
| Feb 11, 2:59 AM CST | Severe Thunderstorm Warning | SHV | Grant, Natchitoches, Winn | 61 min |
| Feb 11, 3:22 AM CST | Severe Thunderstorm Warning | JAN | Ashley | 53 min |
| Feb 11, 3:49 AM CST | Severe Thunderstorm Warning | SHV | Caldwell, Jackson, Ouachita | 41 min |
| Feb 11, 4:09 AM CST | Severe Thunderstorm Warning | LZK | Arkansas, Desha, Drew, Lincoln | 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
Shreveport, LA (KSHV), launched 00:00Z, 7.1 hours before the alert went out and 115 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
- 367 J/kg
- Mixed-layer CIN
- -98 J/kg
- Mixed-layer LCL
- 785 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- 410 m²/s²
- 0-3 km storm-relative helicity
- 547 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 10.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 10, 6:13 PM CST | Mesoscale Discussion | SPC | Crawford, Washington | 92 min |
| Feb 10, 8:34 PM CST | Mesoscale Discussion | SPC | Conway, Crawford, Faulkner, Franklin, Garland, Hempstead and 19 more | 86 min |
| Feb 10, 9:30 PM CST | Tornado Watch | SPC | Baxter, Benton, Boone, Carroll, Clark, Cleburne and 42 more | 7 hr |
| Feb 10, 11:13 PM CST | Mesoscale Discussion | SPC | Baxter, Boone, Cleburne, Conway, Faulkner, Fulton and 18 more | 92 min |
| Feb 10, 11:45 PM CST | Tornado Watch | SPC | Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 12 more | 6 hr |
| Feb 11, 12:37 AM CST | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Cleveland, Desha and 3 more | 53 min |
| Feb 11, 2:30 AM CST | Mesoscale Discussion | SPC | Arkansas, Clay, Craighead, Crittenden, Cross, Fulton and 18 more | 90 min |
| Feb 11, 4:01 AM CST | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 6 more | 89 min |
| Feb 11, 5:26 AM CST | Mesoscale Discussion | SPC | Mississippi | 64 min |
| Feb 11, 9:36 AM CST | Mesoscale Discussion | SPC | George, Greene, Harrison, Jackson | 84 min |
| Feb 10, 7:18 PM CST | Mesoscale Discussion | SPC | Brown, Comanche, Eastland, Erath, Jack, McCulloch and 4 more | 57 min |
| Feb 10, 9:46 PM CST | Mesoscale Discussion | SPC | Austin, Brazoria, Calhoun, Chambers, Colorado, DeWitt and 13 more | 29 min |
| Feb 10, 9:57 PM CST | Severe Thunderstorm Watch | SPC | Aransas, Austin, Bastrop, Bee, Brazoria, Caldwell and 25 more | 5 hr |
Nearby
Tornado Watches in Louisiana, 2009Tornado Watches in Arkansas, 2009Tornado Watches in Mississippi, 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.