Alert archive / Louisiana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 119, NWS Shreveport, LA

May 4, 20215 parishes in Louisiana; Union County, Arkansas

NWS Shreveport, LA issued this severe thunderstorm warning at May 4, 2021, 12:28 PM CDT for 5 parishes in Louisiana; Union County, Arkansas. It was in force for 47 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 4, 2021, 12:28 PM CDT (17:28 UTC)
Expired: May 4, 2021, 1:15 PM CDT
In force: 47 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Union County, AR, Caldwell Parish, LA, Jackson Parish, LA, Ouachita Parish, LA, Union Parish, LA, Winn Parish, LA

The radar

The Shreveport radar (KSHV), 168 km from the middle of the area, began a volume at 17:30 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 was reported inside it

Time	Report	Where	Remark
May 4, 12:42 PM CDT	TSTM WND DMG	4 Sw Claiborne, LA	TREES DOWN IN WESTERN PART OF OUACHITA PARISH IN THE CHENIERE.
May 4, 12:46 PM CDT	TSTM WND DMG	5 Nne Swartz, LA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 4, 10:52 AM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 5.5 hours before the alert went out and 159 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: 2618 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 873 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 208 m²/s²
0-3 km storm-relative helicity: 182 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 6.0

Open this sounding in Storm Lab

The text

As transmitted.

693 
WUUS54 KSHV 041728
SVRSHV
ARC139-LAC021-049-073-111-127-041815-
/O.NEW.KSHV.SV.W.0119.210504T1728Z-210504T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Shreveport LA
1228 PM CDT Tue May 4 2021

The National Weather Service in Shreveport has issued a

* Severe Thunderstorm Warning for...
  Southeastern Union County in south central Arkansas...
  Northern Caldwell Parish in north central Louisiana...
  Southeastern Jackson Parish in north central Louisiana...
  Eastern Union Parish in north central Louisiana...
  Ouachita Parish in north central Louisiana...
  Northeastern Winn Parish in north central Louisiana...

* Until 115 PM CDT.

* At 1228 PM CDT, severe thunderstorms were located along a line
  extending from 6 miles southwest of Lapile to near Claiborne to 15
  miles northwest of Clarks, moving east at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Monroe, Claiborne, West Monroe, Huttig, Columbia, Swartz,
  Brownsville-Bawcom, Brownsville-Bawcomville, Richwood, Sterlington,
  Strong, Lapile, Marion, Felsenthal, Drew, Fondale, Vixen, Bosco,
  Riverton and New London.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 600 PM CDT for south central
Arkansas...and north central Louisiana.

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3207 9193 3204 9191 3212 9237 3256 9233
      3329 9237 3325 9222 3316 9217 3316 9211
      3310 9214 3301 9207 3271 9206 3271 9197
      3266 9191 3251 9190 3228 9203 3227 9199
      3217 9198 3216 9189 3209 9187
TIME...MOT...LOC 1728Z 274DEG 30KT 3301 9233 3256 9228 3219 9232 

HAIL...1.00IN
WIND...60MPH
 
$$

05

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 10:44 AM CDT	Special Weather Statement	SHV	Bossier, Caddo	46 min
May 4, 10:54 AM CDT	Special Weather Statement	SHV	Caddo	66 min
May 4, 11:07 AM CDT	Severe Thunderstorm Warning	SHV	De Soto	38 min
May 4, 11:10 AM CDT	Severe Thunderstorm Warning	SHV	Bienville, Bossier, Caddo, De Soto, Webster	50 min
May 4, 11:14 AM CDT	Severe Thunderstorm Warning	SHV	Bossier, Caddo, De Soto	31 min
May 4, 11:24 AM CDT	Severe Thunderstorm Warning	SHV	Bienville, Claiborne, Jackson, Lincoln	51 min
May 4, 11:45 AM CDT	Special Weather Statement	SHV	Natchitoches	45 min
May 4, 11:48 AM CDT	Special Weather Statement	SHV	Ouachita	42 min
May 4, 12:05 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, De Soto, Natchitoches, Red River, Sabine	40 min
May 4, 12:17 PM CDT	Severe Thunderstorm Warning	SHV	Natchitoches, Sabine	43 min
May 4, 12:25 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Jackson, Lincoln, Ouachita, Union	65 min
May 4, 12:41 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Jackson, Natchitoches, Winn	64 min
May 4, 12:48 PM CDT	Severe Thunderstorm Warning	SHV	Grant, LaSalle, Winn	57 min
May 4, 12:53 PM CDT	Severe Thunderstorm Warning	SHV	Caldwell, Jackson, LaSalle	52 min
May 3, 11:44 PM CDT	Severe Thunderstorm Warning	SHV	Little River	61 min
May 3, 11:59 PM CDT	Special Weather Statement	SHV	Sevier	61 min
May 4, 12:25 AM CDT	Severe Thunderstorm Warning	SHV	Howard, Little River, Sevier	34 min
May 4, 12:34 AM CDT	Severe Thunderstorm Warning	SHV	Hempstead, Howard, Little River, Miller, Sevier	41 min
May 4, 1:19 AM CDT	Special Weather Statement	SHV	Hempstead, Nevada	41 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2021 Severe Thunderstorm Warnings in Arkansas, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.