Alert archive / Louisiana / Tornado Watches in 2010

Tornado Watch 753

November 29, 20104 states

The Storm Prediction Center issued this tornado watch at Nov 29, 2010, 1:31 PM CST for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Nov 29, 2010, 1:31 PM CST (19:31 UTC)
Expired: Nov 29, 2010, 9:00 PM CST
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 72 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Columbia County, AR, Desha County, AR, Drew County, AR, Ouachita County, AR, Union County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis 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, Saint Landry Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bolivar County, MS, Carroll County, MS, Claiborne County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS, Angelina County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 60%
One or more EF2 to EF5 tornadoes: 30%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Nov 29, 2:01 PM CST	Tornado Warning	SHV	Natchitoches, Sabine	29 min
Nov 29, 2:30 PM CST	Tornado Warning	SHV	Grant, Natchitoches, Winn	30 min
Nov 29, 2:57 PM CST	Tornado Warning	SHV	Grant, Winn	33 min
Nov 29, 3:28 PM CST	Tornado Warning	SHV	Caldwell, Jackson, Winn	32 min
Nov 29, 3:37 PM CST	Tornado Warning	SHV	Grant, Natchitoches, Winn	38 min
Nov 29, 3:59 PM CST	Tornado Warning	SHV	Caldwell, Jackson, Ouachita	21 min
Nov 29, 4:02 PM CST	Tornado Warning	SHV	Caldwell, Jackson, Winn	43 min
Nov 29, 4:09 PM CST	Severe Thunderstorm Warning	SHV	De Soto, Sabine	51 min
Nov 29, 4:33 PM CST	Severe Thunderstorm Warning	JAN	Morehouse, Richland, West Carroll	42 min
Nov 29, 5:08 PM CST	Severe Thunderstorm Warning	SHV	Caldwell, Ouachita	37 min
Nov 29, 5:16 PM CST	Severe Thunderstorm Warning	JAN	East Carroll, Richland, West Carroll	59 min
Nov 29, 5:21 PM CST	Severe Thunderstorm Warning	JAN	Franklin, Madison, Richland	54 min
Nov 29, 5:39 PM CST	Severe Thunderstorm Warning	SHV	Natchitoches, Sabine	42 min
Nov 29, 5:50 PM CST	Tornado Warning	JAN	East Carroll, Franklin, Madison, Richland, West Carroll	40 min
Nov 29, 6:16 PM CST	Severe Thunderstorm Warning	JAN	Franklin, Madison, Richland	17 min
Nov 29, 6:59 PM CST	Tornado Warning	JAN	Franklin, Tensas	46 min
Nov 29, 6:59 PM CST	Tornado Warning	JAN	Humphreys, Sharkey, Yazoo	31 min
Nov 29, 7:08 PM CST	Tornado Warning	JAN	East Carroll	37 min
Nov 29, 7:29 PM CST	Tornado Warning	JAN	Holmes, Humphreys, Leflore, Yazoo	46 min
Nov 29, 7:31 PM CST	Tornado Warning	JAN	Humphreys, Issaquena, Sharkey, Yazoo	44 min
Nov 29, 7:33 PM CST	Tornado Warning	JAN	Madison	57 min
Nov 29, 8:05 PM CST	Tornado Warning	JAN	Tensas	55 min
Nov 29, 8:08 PM CST	Tornado Warning	JAN	Attala, Carroll, Holmes, Yazoo	67 min
Nov 29, 8:18 PM CST	Tornado Warning	JAN	Hinds, Madison, Yazoo	57 min
Nov 29, 8:44 PM CST	Tornado Warning	JAN	Claiborne, Hinds, Warren, Yazoo	61 min
Nov 29, 8:55 PM CST	Tornado Warning	JAN	Attala, Holmes, Leake, Madison, Yazoo	50 min
Nov 29, 8:59 PM CST	Tornado Warning	JAN	Catahoula, Concordia, Franklin, Tensas	61 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 12:00Z, 7.5 hours before the alert went out and 146 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 570 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 442 m²/s²
0-3 km storm-relative helicity: 464 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 29, 1:02 PM CST	Mesoscale Discussion	SPC	Ashley, Chicot, Desha, Drew	58 min
Nov 29, 3:29 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Caldwell, Catahoula and 24 more	91 min
Nov 29, 4:41 PM CST	Tornado Watch	SPC	Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee and 6 more	4 hr
Nov 29, 5:55 PM CST	Mesoscale Discussion	SPC	Caldwell, Catahoula, Concordia, East Carroll, Franklin, LaSalle and 4 more	95 min

Nearby

Tornado Watches in Louisiana, 2010 Tornado Watches in Mississippi, 2010 Tornado Watches in Texas, 2010 Every tornado watch in 2010

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.