Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 246, NWS Amarillo, TX

August 11, 2021Dallam County, Sherman County, Texas

NWS Amarillo, TX issued this severe thunderstorm warning at Aug 11, 2021, 4:32 PM CDT for Dallam County, Sherman County, Texas. It was in force for 74 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 11, 2021, 4:32 PM CDT (21:32 UTC)
Expired: Aug 11, 2021, 5:46 PM CDT
In force: 74 min
Issued by: NWS Amarillo, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Dallam County, TX, Sherman County, TX

The radar

The Amarillo radar (KAMA), 135 km from the middle of the area, began a volume at 21:32 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.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 9.5 hours before the alert went out and 136 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: 529 J/kg
Mixed-layer CIN: -225 J/kg
Mixed-layer LCL: 1833 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

036 
WUUS54 KAMA 112132
SVRAMA
TXC111-421-112300-
/O.NEW.KAMA.SV.W.0246.210811T2132Z-210811T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Amarillo TX
432 PM CDT Wed Aug 11 2021

The National Weather Service in Amarillo has issued a

* Severe Thunderstorm Warning for...
  Northwestern Sherman County in the Panhandle of Texas...
  Eastern Dallam County in the Panhandle of Texas...

* Until 600 PM CDT.

* At 432 PM CDT, a severe thunderstorm was located over Conlen, or 14
  miles southwest of Stratford, moving northwest at 10 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to roofs, siding, and trees is possible. 
           Hail damage to vehicles is expected.

* Locations impacted include...
  Stratford and Conlen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3650 10242 3650 10211 3618 10199 3606 10234
      3632 10262
TIME...MOT...LOC 2132Z 155DEG 10KT 3620 10226 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LG

5 follow-up statements

612 
WWUS54 KAMA 112146
SVSAMA

Severe Weather Statement
National Weather Service Amarillo TX
446 PM CDT Wed Aug 11 2021

TXC111-421-112300-
/O.CON.KAMA.SV.W.0246.000000T0000Z-210811T2300Z/
Sherman TX-Dallam TX-
446 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR NORTHWESTERN SHERMAN AND EASTERN DALLAM COUNTIES...

At 445 PM CDT, a severe thunderstorm was located over Stratford,
moving north at 10 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to roofs, siding, and trees is possible. Hail 
         damage to vehicles is expected.

Locations impacted include...
Stratford and Conlen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3650 10242 3650 10211 3618 10199 3606 10234
      3632 10262
TIME...MOT...LOC 2145Z 159DEG 10KT 3630 10205 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LG

092 
WWUS54 KAMA 112204
SVSAMA

Severe Weather Statement
National Weather Service Amarillo TX
504 PM CDT Wed Aug 11 2021

TXC111-421-112300-
/O.CON.KAMA.SV.W.0246.000000T0000Z-210811T2300Z/
Sherman TX-Dallam TX-
504 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR NORTHWESTERN SHERMAN AND EASTERN DALLAM COUNTIES...

At 504 PM CDT, a severe thunderstorm was located over Stratford,
moving northwest at 10 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to roofs, siding, and trees is possible. Hail 
         damage to vehicles is expected.

Locations impacted include...
Stratford and Conlen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3650 10242 3650 10211 3618 10199 3606 10234
      3632 10262
TIME...MOT...LOC 2204Z 155DEG 10KT 3635 10208 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LG

878 
WWUS54 KAMA 112214
SVSAMA

Severe Weather Statement
National Weather Service Amarillo TX
514 PM CDT Wed Aug 11 2021

TXC111-421-112300-
/O.CON.KAMA.SV.W.0246.000000T0000Z-210811T2300Z/
Sherman TX-Dallam TX-
514 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR NORTHWESTERN SHERMAN AND EASTERN DALLAM COUNTIES...

At 514 PM CDT, a severe thunderstorm was located over Stratford,
moving northwest at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Minor damage to roofs, siding, and trees is possible.

Locations impacted include...
Stratford and Conlen. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3650 10242 3650 10211 3623 10201 3611 10239
      3632 10262
TIME...MOT...LOC 2214Z 155DEG 10KT 3638 10210 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LG

405 
WWUS54 KAMA 112227
SVSAMA

Severe Weather Statement
National Weather Service Amarillo TX
527 PM CDT Wed Aug 11 2021

TXC111-421-112300-
/O.CON.KAMA.SV.W.0246.000000T0000Z-210811T2300Z/
Sherman TX-Dallam TX-
527 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR NORTHWESTERN SHERMAN AND NORTHEASTERN DALLAM COUNTIES...

At 526 PM CDT, a severe thunderstorm was located 13 miles northwest
of Conlen, or 19 miles west of Stratford, and is nearly stationary.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Minor damage to roofs, siding, and trees is possible.

Locations impacted include...
Stratford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3650 10242 3650 10211 3628 10203 3622 10251
      3632 10262
TIME...MOT...LOC 2226Z 120DEG 4KT 3638 10241 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LG

442 
WWUS54 KAMA 112246
SVSAMA

Severe Weather Statement
National Weather Service Amarillo TX
546 PM CDT Wed Aug 11 2021

TXC111-421-112256-
/O.CAN.KAMA.SV.W.0246.000000T0000Z-210811T2300Z/
Sherman TX-Dallam TX-
546 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SHERMAN AND
NORTHEASTERN DALLAM COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.  However gusty winds are still possible with this
thunderstorm.

LAT...LON 3650 10242 3650 10211 3628 10203 3622 10251
      3632 10262
TIME...MOT...LOC 2244Z 155DEG 10KT 3643 10244 

$$

LG

The office that day

Everything else NWS Amarillo, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 11, 4:08 PM CDT	Special Weather Statement	AMA	Sherman	37 min
Aug 11, 4:26 PM CDT	Special Weather Statement	AMA	Dallam	34 min
Aug 11, 4:43 PM CDT	Special Weather Statement	AMA	Moore	32 min
Aug 11, 4:58 PM CDT	Severe Thunderstorm Warning	AMA	Hansford, Moore, Sherman	92 min
Aug 11, 5:02 PM CDT	Special Weather Statement	AMA	Deaf Smith	28 min
Aug 11, 5:48 PM CDT	Special Weather Statement	AMA	Dallam	27 min
Aug 11, 6:20 PM CDT	Areal Flood Advisory	AMA	Moore	3 hr
Aug 11, 6:30 PM CDT	Special Weather Statement	AMA	Moore	30 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.