Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 47, NWS Shreveport, LA

April 7, 20214 counties in Texas

NWS Shreveport, LA issued this severe thunderstorm warning at Apr 7, 2021, 4:58 PM CDT for 4 counties in Texas. It was in force for 62 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: Apr 7, 2021, 4:58 PM CDT (21:58 UTC)
Expired: Apr 7, 2021, 6:00 PM CDT
In force: 62 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Angelina County, TX, Nacogdoches County, TX, Sabine County, TX, San Augustine County, TX

The radar

The Ft Polk radar (KPOE), 127 km from the middle of the area, began a volume at 21:57 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
Apr 7, 5:05 PM CDT	TSTM WND DMG	3 Ene Zavalla, TX	TREE AND POWER LINE DOWN ALONG HWY 147 BETWEEN ZAVALLA AND BROADDUS.
Apr 7, 5:30 PM CDT	TSTM WND DMG	11 Sw Pineland, TX	TREE DOWN ON FIRE RD. 705 NEAR POWELL PARK RESORT & MARINA.

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
Apr 7, 12:38 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 10.0 hours before the alert went out and 156 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: 400 J/kg
Mixed-layer CIN: -255 J/kg
Mixed-layer LCL: 795 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 354 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

204 
WUUS54 KSHV 072158
SVRSHV
TXC005-347-403-405-072300-
/O.NEW.KSHV.SV.W.0047.210407T2158Z-210407T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Shreveport LA
458 PM CDT Wed Apr 7 2021

The National Weather Service in Shreveport has issued a

* Severe Thunderstorm Warning for...
  Southeastern Nacogdoches County in eastern Texas...
  Southeastern Angelina County in eastern Texas...
  Southern San Augustine County in eastern Texas...
  Southwestern Sabine County in eastern Texas...

* Until 600 PM CDT.

* At 458 PM CDT, a severe thunderstorm was located 10 miles north of
  Rockland, moving east at 25 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...
  Zavalla, Dolan and Shawnee. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for eastern Texas.

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

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

&&

LAT...LON 3109 9464 3130 9454 3125 9406 3115 9400
      3114 9404 3111 9406 3103 9447
TIME...MOT...LOC 2158Z 275DEG 22KT 3115 9443 

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
Apr 7, 1:22 PM CDT	Severe Thunderstorm Warning	SHV	Sabine, San Augustine, Shelby	38 min
Apr 7, 1:32 PM CDT	Special Weather Statement	SHV	Camp, Upshur	43 min
Apr 7, 2:12 PM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Marion, Upshur	63 min
Apr 7, 2:30 PM CDT	Special Weather Statement	SHV	Cherokee	45 min
Apr 7, 4:02 PM CDT	Special Weather Statement	SHV	Angelina, San Augustine, Shelby	43 min
Apr 7, 4:09 PM CDT	Severe Thunderstorm Warning	SHV	Angelina, Nacogdoches, Sabine, San Augustine	51 min
Apr 7, 4:50 PM CDT	Special Weather Statement	SHV	San Augustine	40 min
Apr 7, 5:36 PM CDT	Severe Thunderstorm Warning	SHV	Sabine	39 min
Apr 7, 6:25 PM CDT	Areal Flood Advisory	SHV	Angelina, Nacogdoches, Sabine, San Augustine	3 hr

Nearby

Severe Thunderstorm Warnings in Texas, 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.