Alert archive / Louisiana / Tornado Watches in 2009
Tornado Watch 143
The Storm Prediction Center issued this tornado watch at Apr 12, 2009, 7:58 AM CDT for 16 parishes in Louisiana; 15 counties in Texas. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2009, 7:58 AM CDT (12:58 UTC)
- Expired
- Apr 12, 2009, 4:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 31 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, San Jacinto County, TX, Tyler County, TX
The radar
The Lake Charles radar (KLCH), 88 km from the middle of the area, began a volume at 13:02 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
- 50%
- 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
- 50%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 90%
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 |
|---|---|---|---|---|
| Apr 12, 9:27 AM CDT | Severe Thunderstorm Warning | HGX | Montgomery, San Jacinto, Trinity, Walker | 48 min |
| Apr 12, 9:46 AM CDT | Severe Thunderstorm Warning | HGX | Polk, San Jacinto, Trinity, Walker | 44 min |
| Apr 12, 10:42 AM CDT | Severe Thunderstorm Warning | HGX | Polk, San Jacinto | 34 min |
| Apr 12, 10:53 AM CDT | Severe Thunderstorm Warning | LCH | Jasper, Tyler | 52 min |
| Apr 12, 11:24 AM CDT | Severe Thunderstorm Warning | HGX | Fort Bend, Harris, Montgomery | 51 min |
| Apr 12, 11:34 AM CDT | Severe Thunderstorm Warning | LCH | Jasper, Newton | 26 min |
| Apr 12, 11:39 AM CDT | Severe Thunderstorm Warning | HGX | Liberty, Montgomery, San Jacinto | 14 min |
| Apr 12, 11:51 AM CDT | Tornado Warning | HGX | Harris | 39 min |
| Apr 12, 12:00 PM CDT | Severe Thunderstorm Warning | LCH | Calcasieu, Cameron | 30 min |
| Apr 12, 12:12 PM CDT | Severe Thunderstorm Warning | LCH | Beauregard, Calcasieu | 33 min |
| Apr 12, 12:15 PM CDT | Severe Thunderstorm Warning | HGX | Chambers, Harris, Liberty | 45 min |
| Apr 12, 12:17 PM CDT | Tornado Warning | HGX | Chambers, Harris, Liberty | 43 min |
| Apr 12, 12:30 PM CDT | Severe Thunderstorm Warning | LCH | Beauregard, Calcasieu, Cameron | 45 min |
| Apr 12, 12:53 PM CDT | Severe Thunderstorm Warning | HGX | Chambers, Liberty | 52 min |
| Apr 12, 12:53 PM CDT | Severe Thunderstorm Warning | LCH | Hardin | 52 min |
| Apr 12, 1:08 PM CDT | Severe Thunderstorm Warning | LCH | Calcasieu, Cameron, Jefferson Davis | 37 min |
| Apr 12, 1:19 PM CDT | Severe Thunderstorm Warning | LCH | Allen, Evangeline, Saint Landry | 41 min |
| Apr 12, 1:24 PM CDT | Severe Thunderstorm Warning | LCH | Hardin, Jefferson | 51 min |
| Apr 12, 1:41 PM CDT | Severe Thunderstorm Warning | LCH | Acadia, Cameron, Jefferson Davis, Lafayette, Saint Landry, Saint Martin and 1 more | 64 min |
| Apr 12, 1:48 PM CDT | Severe Thunderstorm Warning | LCH | Hardin, Jasper, Jefferson, Newton, Orange | 42 min |
| Apr 12, 2:01 PM CDT | Severe Thunderstorm Warning | LCH | Avoyelles, Evangeline, Saint Landry | 44 min |
| Apr 12, 2:38 PM CDT | Severe Thunderstorm Warning | LCH | Beauregard, Calcasieu | 37 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
Lake Charles Mun, LA (KLCH), launched 12:00Z, 1.0 hours before the alert went out and 90 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
- 880 J/kg
- Mixed-layer CIN
- -259 J/kg
- Mixed-layer LCL
- 506 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 326 m²/s²
- 0-3 km storm-relative helicity
- 463 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 7:13 AM CDT | Mesoscale Discussion | SPC | East Carroll, Morehouse, Union, West Carroll | 92 min |
| Apr 12, 7:39 AM CDT | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 11 more | 66 min |
| Apr 12, 9:19 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Caldwell, De Soto, Jackson and 10 more | 56 min |
| Apr 12, 9:30 AM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more | 7 hr |
| Apr 12, 10:53 AM CDT | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more | 2 hr |
| Apr 12, 12:00 PM CDT | Mesoscale Discussion | SPC | Bienville, Caldwell, Claiborne, Jackson, Lincoln, Morehouse and 8 more | 90 min |
| Apr 12, 1:02 PM CDT | Mesoscale Discussion | SPC | Ascension, Assumption, Concordia, East Baton Rouge, East Feliciana, Franklin and 14 more | 88 min |
| Apr 12, 1:53 PM CDT | Tornado Watch | SPC | Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Carroll and 26 more | 7 hr |
| Apr 12, 5:49 PM CDT | Mesoscale Discussion | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more | 86 min |
| Apr 11, 7:41 PM CDT | Severe Thunderstorm Watch | SPC | Callahan, Coke, Coleman, Concho, Crockett, Fisher and 14 more | 5 hr |
| Apr 11, 9:09 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Brown, Callahan, Clay, Coke and 30 more | 96 min |
| Apr 11, 11:44 PM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Clay, Coleman, Comanche, Concho and 22 more | 91 min |
| Apr 12, 12:39 AM CDT | Severe Thunderstorm Watch | SPC | Bandera, Brown, Callahan, Coke, Coleman, Comanche and 38 more | 4 hr |
| Apr 12, 3:55 AM CDT | Mesoscale Discussion | SPC | Atascosa, Austin, Bandera, Bastrop, Bell, Bexar and 49 more | 95 min |
| Apr 12, 4:37 AM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Fort Bend, Hardin, Harris, Jasper and 8 more | 83 min |
| Apr 12, 2:24 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Clay, Foard, Hardeman, Jack and 7 more | 96 min |
| Apr 12, 5:20 PM CDT | Mesoscale Discussion | SPC | Clay, Collin, Cooke, Denton, Grayson, Jack and 5 more | 55 min |
Nearby
Tornado Watches in Louisiana, 2009Tornado Watches in Texas, 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.