Alert archive / Louisiana / Tornado Watches in 2008

Tornado Watch 254

May 2, 200826 parishes in Louisiana; 13 counties in Mississippi

The Storm Prediction Center issued this tornado watch at May 2, 2008, 5:18 PM CDT for 26 parishes in Louisiana; 13 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 2, 2008, 5:18 PM CDT (22:18 UTC)
Expired: May 2, 2008, 11:41 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 3 in
Strongest gust expected: 60 kt

All 39 counties

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 Carroll 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, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lincoln County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Warren County, MS

The radar

The Shreveport radar (KSHV), 145 km from the middle of the area, began a volume at 22:18 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: 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

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

Issued	Product	Office	Counties	Lasted
May 2, 7:14 PM CDT	Severe Thunderstorm Warning	SHV	Ouachita	31 min
May 2, 7:16 PM CDT	Severe Thunderstorm Warning	JAN	Morehouse, West Carroll	44 min
May 2, 7:19 PM CDT	Tornado Warning	JAN	Morehouse, West Carroll	56 min
May 2, 7:33 PM CDT	Severe Thunderstorm Warning	SHV	Lincoln, Union	57 min
May 2, 7:44 PM CDT	Severe Thunderstorm Warning	SHV	Bossier, Webster	61 min
May 2, 7:50 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Jackson	55 min
May 2, 8:00 PM CDT	Tornado Warning	JAN	Morehouse	45 min
May 2, 8:20 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne	55 min
May 2, 8:38 PM CDT	Severe Thunderstorm Warning	SHV	Jackson, Lincoln, Ouachita	67 min
May 2, 8:47 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Jackson	43 min
May 2, 9:08 PM CDT	Severe Thunderstorm Warning	JAN	Morehouse	67 min
May 2, 9:14 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Union, Webster	31 min
May 2, 9:25 PM CDT	Severe Thunderstorm Warning	SHV	Lincoln, Union	65 min
May 2, 9:33 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Claiborne, Lincoln, Webster	57 min
May 2, 9:41 PM CDT	Severe Thunderstorm Warning	SHV	Jackson, Lincoln, Ouachita, Union	64 min
May 2, 9:46 PM CDT	Severe Thunderstorm Warning	SHV	Jackson, Ouachita	59 min
May 2, 9:52 PM CDT	Severe Thunderstorm Warning	SHV	De Soto, Sabine	38 min
May 2, 9:54 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Union	66 min
May 2, 10:27 PM CDT	Severe Thunderstorm Warning	SHV	Bossier, Caddo, De Soto	34 min
May 2, 10:30 PM CDT	Severe Thunderstorm Warning	SHV	Union	37 min
May 2, 10:44 PM CDT	Severe Thunderstorm Warning	SHV	Ouachita	61 min
May 2, 11:01 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Jackson, Winn	59 min
May 2, 11:20 PM CDT	Severe Thunderstorm Warning	JAN	Morehouse	32 min
May 2, 11:21 PM CDT	Severe Thunderstorm Warning	SHV	Natchitoches, Winn	54 min
May 2, 11:32 PM CDT	Severe Thunderstorm Warning	SHV	Sabine	43 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, 10.3 hours before the alert went out and 136 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: 2045 J/kg
Mixed-layer CIN: -107 J/kg
Mixed-layer LCL: 641 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 306 m²/s²
0-3 km storm-relative helicity: 329 m²/s²
Significant tornado parameter: 1.9
Supercell composite: 7.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 8:49 AM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more	6 hr
May 2, 12:12 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caldwell, Claiborne, East Carroll, Jackson and 8 more	2 hr
May 2, 2:21 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 23 more	114 min
May 2, 1:54 PM CDT	Tornado Watch	SPC	Alcorn, Benton, Bolivar, Calhoun, Coahoma, DeSoto and 15 more	6 hr
May 2, 3:35 PM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Bolivar, Calhoun, Carroll, Chickasaw and 23 more	85 min
May 2, 4:43 PM CDT	Tornado Watch	SPC	Attala, Carroll, Chickasaw, Choctaw, Clay, Holmes and 16 more	7 hr

Nearby

Tornado Watches in Louisiana, 2008 Tornado Watches in Mississippi, 2008 Every tornado watch in 2008

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.