Alert archive / Louisiana / Severe Thunderstorm Watches in 2005

Severe Thunderstorm Watch 839

October 31, 200514 counties in Arkansas; 17 parishes in Louisiana; San Augustine County, Shelby County, Texas

The Storm Prediction Center issued this severe thunderstorm watch at Oct 31, 2005, 1:35 PM CST for 14 counties in Arkansas; 17 parishes in Louisiana; San Augustine County, Shelby County, Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Oct 31, 2005, 1:35 PM CST (19:35 UTC)
Expired: Oct 31, 2005, 8:00 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 33 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Drew County, AR, Hempstead County, AR, Lafayette County, AR, Lincoln County, AR, Miller County, AR, Nevada County, AR, Ouachita 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, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, San Augustine County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 86 km from the middle of the area, began a volume at 19:36 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Oct 31, 1:40 PM CST	Severe Thunderstorm Warning	SHV	Lafayette	65 min
Oct 31, 1:46 PM CST	Severe Thunderstorm Warning	SHV	Caddo	44 min
Oct 31, 2:57 PM CST	Severe Thunderstorm Warning	SHV	Bossier	33 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, 7.6 hours before the alert went out and 78 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: 1173 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 169 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 31, 1:53 PM CST	Mesoscale Discussion	SPC	Bradley, Calhoun, Cleveland, Columbia, Hempstead, Lafayette and 4 more	97 min
Oct 31, 2:54 PM CST	Mesoscale Discussion	SPC	Beauregard, Calcasieu, Cameron, Vernon	66 min
Oct 31, 3:10 PM CST	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 8 more	6 hr
Oct 31, 5:10 PM CST	Mesoscale Discussion	SPC	Caldwell, Grant, Jackson, LaSalle, Natchitoches, Ouachita and 2 more	95 min
Oct 30, 11:48 PM CST	Mesoscale Discussion	SPC	Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler	117 min
Oct 31, 10:55 AM CST	Mesoscale Discussion	SPC	Anderson, Austin, Bastrop, Bell, Blanco, Brazos and 33 more	65 min
Oct 31, 11:25 AM CST	Severe Thunderstorm Watch	SPC	Anderson, Angelina, Atascosa, Austin, Bastrop, Bell and 54 more	7 hr
Oct 31, 5:26 PM CST	Mesoscale Discussion	SPC	Bee, Brooks, Cameron, Duval, Hidalgo, Jim Hogg and 9 more	94 min

Nearby

Severe Thunderstorm Watches in Louisiana, 2005 Severe Thunderstorm Watches in Arkansas, 2005 Severe Thunderstorm Watches in Texas, 2005 Every severe thunderstorm watch in 2005

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.