Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 263

June 12, 2021Cimarron County, Texas County, Oklahoma; 27 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Jun 12, 2021, 9:39 PM CDT for Cimarron County, Texas County, Oklahoma; 27 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 12, 2021, 9:39 PM CDT (02:39 UTC)
Expired
Jun 13, 2021, 4:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
70 kt
All 29 counties

Cimarron County, OK, Texas County, OK, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Collingsworth County, TX, Dallam County, TX, Deaf Smith County, TX, Donley County, TX, Floyd County, TX, Gray County, TX, Hale County, TX, Hansford County, TX, Hartley County, TX, Hemphill County, TX, Hutchinson County, TX, Lamb County, TX, Moore County, TX, Ochiltree County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Sherman County, TX, Swisher County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 56 km from the middle of the area, began a volume at 02:42 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 12, 10:02 PM CDTSevere Thunderstorm WarningAMADeaf Smith, Oldham73 min
Jun 12, 10:32 PM CDTSevere Thunderstorm WarningAMACimarron, Texas58 min
Jun 12, 11:01 PM CDTSevere Thunderstorm WarningAMACimarron, Texas74 min
Jun 12, 11:07 PM CDTSevere Thunderstorm WarningAMADeaf Smith, Hartley, Oldham83 min
Jun 12, 11:46 PM CDTSevere Thunderstorm WarningAMADallam, Hansford, Hartley, Hutchinson, Moore, Oldham and 2 more59 min
Jun 13, 12:42 AM CDTSevere Thunderstorm WarningAMACarson, Hansford, Hartley, Hutchinson, Moore, Ochiltree and 4 more63 min
Jun 13, 1:15 AM CDTSevere Thunderstorm WarningAMAArmstrong, Carson, Gray, Hutchinson, Potter, Randall and 1 more45 min
Jun 13, 1:56 AM CDTSevere Thunderstorm WarningAMAArmstrong, Carson, Donley, Gray, Hemphill, Hutchinson and 3 more64 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 2.7 hours before the alert went out and 56 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-pSkew-T log-p diagram, Amarillo Airport, TX at 00:00Z on 2021-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3697 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2021-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
3697 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1361 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
190 m²/s²
Significant tornado parameter
1.9
Supercell composite
18.7

Open this sounding in Storm Lab

The text

As transmitted.

833 
WWUS20 KWNS 130237
SEL3  
SPC WW 130237
OKZ000-TXZ000-130800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 263
NWS Storm Prediction Center Norman OK
940 PM CDT Sat Jun 12 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Oklahoma Panhandle
  Texas Panhandle

* Effective this Saturday night and Sunday morning from 940 PM
  until 300 AM CDT.

* Primary threats include...
  Scattered damaging winds and isolated significant gusts to 80
    mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Storms moving off the higher terrain will pose a risk for
damaging wind and large hail as they continue east through the
Oklahoma and Texas Panhandles this evening.

The severe thunderstorm watch area is approximately along and 55
statute miles east and west of a line from 40 miles northwest of
Guymon OK to 35 miles south southwest of Plainview TX. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU3).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 262...

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
29035.

...Dial

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 12, 9:23 PM CDTMesoscale DiscussionSPCCimarron67 min
Jun 12, 11:33 PM CDTMesoscale DiscussionSPCCimarron, Texas87 min
Jun 13, 12:53 AM CDTMesoscale DiscussionSPCHarmon, Roger Mills, Texas97 min
Jun 13, 6:31 PM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Carter, Comanche, Cotton and 9 more119 min

Nearby

Severe Thunderstorm Watches in Texas, 2021Severe Thunderstorm Watches in Oklahoma, 2021Every severe thunderstorm watch 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.