Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 228

May 30, 20219 counties in Oklahoma; 10 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 30, 2021, 9:17 PM CDT for 9 counties in Oklahoma; 10 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 30, 2021, 9:17 PM CDT (02:17 UTC)
Expired
May 31, 2021, 2:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Beaver County, OK, Beckham County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Roger Mills County, OK, Woodward County, OK, Armstrong County, TX, Carson County, TX, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Lipscomb County, TX, Potter County, TX, Randall County, TX, Wheeler County, TX

The radar

The Vance AFB radar (KVNX), 175 km from the middle of the area, began a volume at 02:18 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
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
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 30, 10:27 PM CDTSevere Thunderstorm WarningAMAArmstrong, Carson, Potter, Randall63 min
May 30, 10:38 PM CDTTornado WarningAMACarson, Gray22 min
May 30, 10:57 PM CDTFlash Flood WarningAMAArmstrong, Carson, Potter, Randall4 hr
May 31, 12:41 AM CDTFlash Flood WarningAMAArmstrong, Carson, Randall3 hr
May 31, 12:47 AM CDTSevere Thunderstorm WarningAMACollingsworth, Wheeler58 min
May 31, 1:28 AM CDTFlash Flood WarningAMADonley, Gray3 hr

Discussions around it

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

The nearest sounding before it

Dodge City, (KDDC), launched 00:00Z, 2.3 hours before the alert went out and 183 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, Dodge City, at 00:00Z on 2021-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Dodge City, at 00:00Z on 2021-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
700 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

088 
WWUS20 KWNS 310214
SEL8  
SPC WW 310214
OKZ000-TXZ000-310700-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 228
NWS Storm Prediction Center Norman OK
915 PM CDT Sun May 30 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Western Oklahoma
  Eastern Texas Panhandle

* Effective this Sunday night and Monday morning from 915 PM
  until 200 AM CDT.

* Primary threats include...
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible
  A tornado or two possible

SUMMARY...A cluster of storms will continue to progress eastward
across the eastern Texas/Oklahoma Panhandles toward other parts of
western Oklahoma. Isolated damaging wind gusts and possibly some
hail may occur before storms weaken into the overnight.

The severe thunderstorm watch area is approximately along and 40
statute miles east and west of a line from 40 miles east of Liberal
KS to 170 miles south southeast of Liberal KS. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).

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 226...WW 227...

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
28025.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 30, 8:59 PM CDTMesoscale DiscussionSPCBeaver, Dewey, Ellis, Roger Mills, Woodward91 min
May 30, 9:22 PM CDTMesoscale DiscussionSPCAndrews, Borden, Cochran, Cottle, Crosby, Dawson and 20 more83 min
May 30, 11:43 PM CDTMesoscale DiscussionSPCBailey, Cochran, Cottle, Crosby, Dickens, Floyd and 12 more92 min
May 31, 2:12 AM CDTMesoscale DiscussionSPCBorden, Fisher, Haskell, Howard, Jones, Kent and 5 more3 hr
May 31, 11:33 AM CDTMesoscale DiscussionSPCAndrews, Borden, Brewster, Cochran, Crane, Crockett and 26 more87 min
May 31, 12:16 PM CDTSevere Thunderstorm WatchSPCAndrews, Coke, Crane, Crockett, Culberson, Ector and 21 more9 hr
May 31, 2:15 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Comanche, Coryell and 10 more2 hr
May 31, 2:54 PM CDTSevere Thunderstorm WatchSPCBell, Bosque, Comanche, Coryell, Ellis, Erath and 13 more4 hr
May 31, 3:29 PM CDTMesoscale DiscussionSPCAndrews, Coke, Crane, Crockett, Culberson, Ector and 21 more91 min
May 31, 5:12 PM CDTMesoscale DiscussionSPCBell, Bosque, Coryell, Ellis, Falls, Freestone and 10 more93 min
May 31, 5:49 PM CDTMesoscale DiscussionSPCBrewster, Pecos, Terrell116 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.