Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 218

May 28, 202128 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 28, 2021, 12:14 PM CDT for 28 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 28, 2021, 12:14 PM CDT (17:14 UTC)
Expired
May 28, 2021, 7:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 28 counties

Bell County, TX, Bosque County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Comanche County, TX, Coryell County, TX, Eastland County, TX, Erath County, TX, Falls County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Palo Pinto County, TX, Robertson County, TX, Somervell County, TX, Stephens County, TX, Washington County, TX, Williamson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 101 km from the middle of the area, began a volume at 17:15 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
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 28, 12:47 PM CDTSevere Thunderstorm WarningFWDHamilton, Mills58 min
May 28, 1:21 PM CDTSevere Thunderstorm WarningFWDMcLennan54 min
May 28, 1:26 PM CDTSevere Thunderstorm WarningFWDCoryell, Lampasas79 min
May 28, 1:43 PM CDTSevere Thunderstorm WarningFWDHamilton32 min
May 28, 2:44 PM CDTSevere Thunderstorm WarningFWDBell, Coryell, Falls, McLennan61 min
May 28, 2:51 PM CDTFlash Flood WarningFWDMcLennan3 hr
May 28, 4:38 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano52 min
May 28, 5:15 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano60 min
May 28, 5:28 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano62 min
May 28, 5:50 PM CDTSevere Thunderstorm WarningEWXLlano40 min
May 28, 6:12 PM CDTSevere Thunderstorm WarningEWXBlanco, Burnet, Travis, Williamson63 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

Fort Worth, TX (KFWD), launched 12:00Z, 5.2 hours before the alert went out and 128 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, Fort Worth, TX at 12:00Z on 2021-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 313 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, Fort Worth, TX at 12:00Z on 2021-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.19395878Sfc1 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
313 J/kg
Mixed-layer CIN
-386 J/kg
Mixed-layer LCL
694 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.0

Open this sounding in Storm Lab

The text

As transmitted.

138 
WWUS20 KWNS 281709
SEL8  
SPC WW 281709
TXZ000-290000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 218
NWS Storm Prediction Center Norman OK
1210 PM CDT Fri May 28 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Central Texas

* Effective this Friday afternoon and evening from 1210 PM until
  700 PM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...A cluster of thunderstorms has developed over central
Texas.  These storms are expected to persist through the afternoon
and build southeastward across the watch area.  Large hail and
damaging wind gusts will be possible with the more intense cells.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 20 miles north of
Brownwood TX to 30 miles east northeast of College Station TX. 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.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
29025.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 27, 10:24 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Haskell, Jack, Knox and 7 more96 min
May 28, 2:33 AM CDTMesoscale DiscussionSPCCollin, Denton, Hunt, Rockwall, Wise117 min
May 28, 5:10 AM CDTMesoscale DiscussionSPCBriscoe, Castro, Childress, Cottle, Floyd, Foard and 7 more2 hr
May 28, 11:16 AM CDTMesoscale DiscussionSPCBell, Bosque, Brazos, Brown, Burleson, Coleman and 19 more89 min
May 28, 12:49 PM CDTMesoscale DiscussionSPCBrewster, Pecos, Presidio, Terrell86 min
May 28, 1:03 PM CDTMesoscale DiscussionSPCAndrews, Bailey, Borden, Cochran, Dawson, Ector and 11 more57 min
May 28, 2:33 PM CDTMesoscale DiscussionSPCAndrews, Borden, Brown, Coke, Coleman, Concho and 35 more117 min
May 28, 2:45 PM CDTSevere Thunderstorm WatchSPCBrewster, Culberson, Jeff Davis, Loving, Pecos, Reeves and 3 more9 hr
May 28, 3:41 PM CDTSevere Thunderstorm WatchSPCAndrews, Brown, Coke, Coleman, Concho, Crane and 20 more8 hr
May 28, 3:42 PM CDTMesoscale DiscussionSPCBell, Brazos, Brown, Burleson, Burnet, Comanche and 12 more93 min
May 28, 5:54 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 29 more96 min
May 28, 6:20 PM CDTSevere Thunderstorm WatchSPCAtascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 32 more5 hr
May 28, 6:49 PM CDTMesoscale DiscussionSPCBailey, Deaf Smith, Parmer86 min

Nearby

Severe Thunderstorm Watches in Texas, 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.