Alert archive / Texas / Tornado Warnings in 2021

Tornado Warning 25, NWS Shreveport, LA

May 20, 2021Harrison County, Texas

NWS Shreveport, LA issued this tornado warning at May 20, 2021, 4:20 PM CDT for Harrison County, Texas. It was in force for 25 min. 1 report 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 20, 2021, 4:20 PM CDT (21:20 UTC)
Expired: May 20, 2021, 4:45 PM CDT
In force: 25 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Harrison County, TX

The radar

The Shreveport radar (KSHV), 74 km from the middle of the area, began a volume at 21:22 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 20, 4:38 PM CDT	TORNADO	4 Nnw Hallsville, TX	STORM CHASER DRONE FOOTAGE OBSERVED A VERY BRIEF TORNADO CROSSING A SMALL POND AND PRODUCING NO DAMAGE INDICATORS.

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

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 9.3 hours before the alert went out and 82 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: 4 J/kg
Mixed-layer CIN: -179 J/kg
Mixed-layer LCL: 739 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 182 m²/s²
0-3 km storm-relative helicity: 210 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

491 
WFUS54 KSHV 202120
TORSHV
TXC203-202145-
/O.NEW.KSHV.TO.W.0025.210520T2120Z-210520T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Shreveport LA
420 PM CDT Thu May 20 2021

The National Weather Service in Shreveport has issued a

* Tornado Warning for...
  West central Harrison County in northeastern Texas...

* Until 445 PM CDT.
    
* At 420 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Hallsville, or 8 miles southeast of Longview,
  moving north at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Hallsville around 435 PM CDT.
  Longview around 440 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3242 9461 3242 9467 3263 9470 3261 9453
TIME...MOT...LOC 2120Z 181DEG 22KT 3244 9464 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

13

1 follow-up statement

073 
WWUS54 KSHV 202135
SVSSHV

Severe Weather Statement
National Weather Service Shreveport LA
435 PM CDT Thu May 20 2021

TXC203-202145-
/O.CON.KSHV.TO.W.0025.000000T0000Z-210520T2145Z/
Harrison TX-
435 PM CDT Thu May 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR WEST
CENTRAL HARRISON COUNTY...
    
At 435 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Hallsville, or 7 miles east of Longview, moving
north at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
west central Harrison County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3248 9462 3248 9465 3263 9467 3261 9456
TIME...MOT...LOC 2135Z 181DEG 22KT 3253 9463 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

13

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 3:52 PM CDT	Special Weather Statement	SHV	Gregg	38 min

Nearby

Tornado Warnings in Texas, 2021 Every tornado warning in 2021 Tornadoes 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.