Alert archive / Louisiana / Tornado Watches in 2010

Tornado Watch 1

January 20, 201043 parishes in Louisiana; 36 counties in Mississippi; 9 counties in Texas

The Storm Prediction Center issued this tornado watch at Jan 20, 2010, 3:13 PM CST for 43 parishes in Louisiana; 36 counties in Mississippi; 9 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jan 20, 2010, 3:13 PM CST (21:13 UTC)
Expired: Jan 20, 2010, 10:00 PM CST
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 88 counties

Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Livingston Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Washington Parish, LA, Webster Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Hinds County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Pearl River County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Yazoo County, MS, Angelina County, TX, Hardin County, TX, Jasper County, TX, Nacogdoches County, TX, Newton 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: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 20, 3:17 PM CST	Severe Thunderstorm Warning	LCH	Avoyelles, Saint Landry	58 min
Jan 20, 3:21 PM CST	Severe Thunderstorm Warning	JAN	Concordia	32 min
Jan 20, 3:22 PM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	53 min
Jan 20, 3:27 PM CST	Tornado Warning	LCH	Avoyelles, Saint Landry	29 min
Jan 20, 3:42 PM CST	Severe Thunderstorm Warning	LIX	Tangipahoa	33 min
Jan 20, 3:58 PM CST	Severe Thunderstorm Warning	JAN	Adams, Jefferson	23 min
Jan 20, 4:01 PM CST	Tornado Warning	LIX	Tangipahoa, Washington	44 min
Jan 20, 4:07 PM CST	Severe Thunderstorm Warning	JAN	Hinds	22 min
Jan 20, 4:10 PM CST	Severe Thunderstorm Warning	LIX	West Feliciana	65 min
Jan 20, 4:17 PM CST	Tornado Warning	SHV	Sabine, San Augustine, Shelby	43 min
Jan 20, 4:28 PM CST	Severe Thunderstorm Warning	LIX	East Baton Rouge, Iberville, Pointe Coupee, West Baton Rouge	34 min
Jan 20, 4:41 PM CST	Tornado Warning	LIX	Washington	34 min
Jan 20, 4:48 PM CST	Tornado Warning	SHV	Sabine	42 min
Jan 20, 5:01 PM CST	Severe Thunderstorm Warning	SHV	Caddo	29 min
Jan 20, 5:07 PM CST	Severe Thunderstorm Warning	JAN	Hinds, Madison	38 min
Jan 20, 5:14 PM CST	Tornado Warning	SHV	Caddo	46 min
Jan 20, 5:15 PM CST	Tornado Warning	LIX	Washington	30 min
Jan 20, 5:28 PM CST	Flash Flood Warning	JAN	Hinds, Issaquena, Madison, Warren, Yazoo	75 min
Jan 20, 5:29 PM CST	Tornado Warning	SHV	Natchitoches, Sabine	46 min
Jan 20, 5:37 PM CST	Severe Thunderstorm Warning	JAN	Hinds, Madison, Yazoo	53 min
Jan 20, 5:42 PM CST	Tornado Warning	JAN	Hinds, Madison	49 min
Jan 20, 5:42 PM CST	Severe Thunderstorm Warning	LIX	Pearl River	18 min
Jan 20, 5:45 PM CST	Tornado Warning	LIX	Washington	29 min
Jan 20, 5:48 PM CST	Tornado Warning	LIX	Pike	16 min
Jan 20, 5:58 PM CST	Tornado Warning	SHV	Bossier, Caddo	47 min
Jan 20, 6:03 PM CST	Severe Thunderstorm Warning	JAN	Covington, Jefferson Davis, Lawrence	57 min
Jan 20, 6:04 PM CST	Flash Flood Warning	JAN	Madison, Yazoo	61 min
Jan 20, 6:08 PM CST	Severe Thunderstorm Warning	SHV	Bossier, Webster	52 min
Jan 20, 6:10 PM CST	Tornado Warning	LIX	Livingston, Saint Helena, Tangipahoa	35 min
Jan 20, 6:11 PM CST	Tornado Warning	SHV	Natchitoches, Winn	34 min
Jan 20, 6:25 PM CST	Severe Thunderstorm Warning	LIX	Pike, Walthall	25 min
Jan 20, 6:30 PM CST	Severe Thunderstorm Warning	JAN	Madison, Rankin	33 min
Jan 20, 6:42 PM CST	Severe Thunderstorm Warning	SHV	Jackson, Winn	33 min
Jan 20, 6:44 PM CST	Tornado Warning	LIX	Tangipahoa, Washington	41 min
Jan 20, 6:53 PM CST	Severe Thunderstorm Warning	SHV	Bossier, Claiborne, Webster	52 min
Jan 20, 7:03 PM CST	Tornado Warning	SHV	Jackson, Winn	42 min
Jan 20, 7:27 PM CST	Severe Thunderstorm Warning	SHV	Claiborne, Webster	48 min
Jan 20, 7:41 PM CST	Tornado Warning	SHV	Caldwell, Jackson, Ouachita, Winn	34 min
Jan 20, 8:04 PM CST	Flash Flood Warning	JAN	Neshoba	116 min
Jan 20, 8:05 PM CST	Severe Thunderstorm Warning	JAN	Copiah	22 min
Jan 20, 8:08 PM CST	Flash Flood Warning	JAN	Clarke	3 hr
Jan 20, 8:09 PM CST	Severe Thunderstorm Warning	JAN	Morehouse, Richland	51 min
Jan 20, 8:11 PM CST	Tornado Warning	SHV	Caldwell, Ouachita	34 min
Jan 20, 8:22 PM CST	Flash Flood Warning	JAN	Lamar	3 hr
Jan 20, 8:33 PM CST	Severe Thunderstorm Warning	JAN	Hinds	28 min
Jan 20, 8:44 PM CST	Severe Thunderstorm Warning	JAN	Catahoula, Franklin, Tensas	61 min
Jan 20, 9:19 PM CST	Flash Flood Warning	SHV	Claiborne, Union	6 hr
Jan 20, 9:28 PM CST	Flash Flood Warning	JAN	Jefferson Davis, Lawrence, Marion	3 hr
Jan 20, 9:46 PM CST	Flash Flood Warning	JAN	Madison, Tensas	4 hr
Jan 20, 10:00 PM CST	Severe Thunderstorm Warning	JAN	Madison, Tensas	60 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, 9.2 hours before the alert went out and 144 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: 1343 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 449 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 192 m²/s²
0-3 km storm-relative helicity: 208 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 20, 2:22 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 13 more	83 min
Jan 19, 10:11 PM CST	Mesoscale Discussion	SPC	Bowie, Red River	2 hr
Jan 20, 1:49 PM CST	Mesoscale Discussion	SPC	Archer, Baylor, Bosque, Brown, Clay, Comanche and 18 more	86 min
Jan 20, 3:52 PM CST	Tornado Watch	SPC	Anderson, Bowie, Camp, Cass, Cherokee, Collin and 38 more	6 hr

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.