Alert archive / Louisiana / Severe Thunderstorm Watches in 1997

Severe Thunderstorm Watch 174

April 21, 19974 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 21, 1997, 10:00 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Apr 21, 1997, 10:00 PM CDT (03:00 UTC)
Expired: Apr 22, 1997, 4:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 45 counties

Ashley County, AR, Columbia County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Union County, AR, 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, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 45 km from the middle of the area, began a volume at 03:04 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

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

Issued	Product	Office	Counties	Lasted
Apr 21, 10:14 PM CDT	Severe Thunderstorm Warning	SHV	Bowie	61 min
Apr 21, 11:40 PM CDT	Severe Thunderstorm Warning	SHV	Caddo	65 min
Apr 22, 12:31 AM CDT	Severe Thunderstorm Warning	SHV	Upshur	59 min
Apr 22, 12:56 AM CDT	Severe Thunderstorm Warning	SHV	Harrison	64 min
Apr 22, 1:00 AM CDT	Severe Thunderstorm Warning	SHV	Gregg, Smith	60 min
Apr 22, 1:58 AM CDT	Severe Thunderstorm Warning	SHV	Gregg	62 min
Apr 22, 2:12 AM CDT	Severe Thunderstorm Warning	SHV	Caddo	63 min
Apr 22, 2:56 AM CDT	Severe Thunderstorm Warning	SHV	Bossier	49 min
Apr 22, 3:05 AM CDT	Severe Thunderstorm Warning	SHV	Cass	55 min
Apr 22, 3:33 AM CDT	Severe Thunderstorm Warning	SHV	Caddo, De Soto	57 min

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 3.0 hours before the alert went out and 41 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: 310 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1727 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 22, 5:00 AM CDT	Severe Thunderstorm Watch	SPC	Ashley, Bradley, Calhoun, Clark, Cleveland, Columbia and 13 more	6 hr
Apr 22, 8:45 AM CDT	Tornado Watch	SPC	Ashley, Chicot	6 hr
Apr 22, 1:00 AM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Natchitoches and 3 more	5 hr
Apr 22, 1:15 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more	6 hr
Apr 22, 2:30 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Ascension, Assumption, Avoyelles, Catahoula, Concordia and 24 more	7 hr
Apr 22, 11:15 AM CDT	Tornado Watch	SPC	Attala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 28 more	6 hr
Apr 22, 1:30 PM CDT	Tornado Watch	SPC	Clarke, Forrest, George, Greene, Hancock, Harrison and 11 more	8 hr
Apr 21, 9:00 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Briscoe, Carson, Childress, Collingsworth, Dallam and 16 more	6 hr
Apr 22, 1:45 AM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Briscoe, Childress, Clay, Collin and 32 more	4 hr

Nearby

Severe Thunderstorm Watches in Louisiana, 1997 Severe Thunderstorm Watches in Texas, 1997 Severe Thunderstorm Watches in Arkansas, 1997 Every severe thunderstorm watch in 1997

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.