Alert archive / Louisiana / Tornado Watches in 2009
Tornado Watch 630
The Storm Prediction Center issued this tornado watch at Jul 28, 2009, 7:58 AM CDT for 4 counties in Arkansas; 16 parishes in Louisiana; 14 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 28, 2009, 7:58 AM CDT (12:58 UTC)
- Expired
- Jul 28, 2009, 3:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 34 counties
Columbia County, AR, Lafayette County, AR, Miller County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 44 km from the middle of the area, began a volume at 13:00 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
- 30%
- One or more gusts of 65 knots or more
- 20%
- 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
- 50%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 8:03 AM CDT | Tornado Warning | SHV | Caddo | 42 min |
| Jul 28, 8:07 AM CDT | Flash Flood Warning | SHV | Webster | 3 hr |
| Jul 28, 8:24 AM CDT | Severe Thunderstorm Warning | SHV | Bossier, Webster | 51 min |
| Jul 28, 8:33 AM CDT | Flash Flood Warning | SHV | Gregg, Harrison, Upshur | 3 hr |
| Jul 28, 9:10 AM CDT | Severe Thunderstorm Warning | SHV | Bossier, Webster | 50 min |
| Jul 28, 9:44 AM CDT | Severe Thunderstorm Warning | SHV | Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more | 61 min |
| Jul 28, 10:46 AM CDT | Flash Flood Warning | SHV | Bienville, De Soto, Red River | 4 hr |
| Jul 28, 10:53 AM CDT | Flash Flood Warning | SHV | Webster | 112 min |
| Jul 28, 11:18 AM CDT | Flash Flood Warning | SHV | Caldwell, Jackson, Natchitoches, Winn | 4 hr |
| Jul 28, 11:22 AM CDT | Flash Flood Warning | SHV | Bossier, Caddo | 3 hr |
| Jul 28, 2:07 PM CDT | Flash Flood Warning | SHV | Harrison, Marion | 3 hr |
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 12:00Z, 1.0 hours before the alert went out and 44 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
- 1892 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 472 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 216 m²/s²
- 0-3 km storm-relative helicity
- 320 m²/s²
- Significant tornado parameter
- 2.2
- Supercell composite
- 10.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 1:41 AM CDT | Mesoscale Discussion | SPC | Columbia, Lafayette, Miller, Union | 94 min |
| Jul 28, 5:57 AM CDT | Mesoscale Discussion | SPC | Bradley, Calhoun, Columbia, Dallas, Hempstead, Lafayette and 5 more | 78 min |
| Jul 28, 11:25 AM CDT | Mesoscale Discussion | SPC | Ashley, Columbia, Union | 65 min |
| Jul 28, 2:18 PM CDT | Mesoscale Discussion | SPC | Avoyelles, Catahoula, Concordia, East Baton Rouge, East Feliciana, Evangeline and 8 more | 57 min |
| Jul 28, 1:26 PM CDT | Mesoscale Discussion | SPC | Bailey, Cochran, Dallam, Deaf Smith, Hartley, Oldham and 2 more | 94 min |
| Jul 28, 2:16 PM CDT | Severe Thunderstorm Watch | SPC | Bailey, Dallam, Deaf Smith, Hartley, Oldham, Parmer | 8 hr |
| Jul 28, 5:47 PM CDT | Mesoscale Discussion | SPC | Armstrong, Carson, Donley, Gray, Hansford, Hemphill and 9 more | 88 min |
| Jul 28, 6:09 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Cochran and 26 more | 7 hr |
Nearby
Tornado Watches in Louisiana, 2009Tornado Watches in Texas, 2009Tornado Watches in Arkansas, 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.