Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 23

March 16, 202150 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Mar 16, 2021, 10:26 PM CDT for 50 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 16, 2021, 10:26 PM CDT (03:26 UTC)
Expired
Mar 17, 2021, 5:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 50 counties

Bell County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Coryell County, TX, Crockett County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fisher County, TX, Hamilton County, TX, Haskell County, TX, Hill County, TX, Hood County, TX, Irion County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Kimble County, TX, Lampasas County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Mills County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Sterling County, TX, Sutton County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wise County, TX, Young County, TX

The radar

The San Angelo radar (KSJT), 93 km from the middle of the area, began a volume at 03:23 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
60%
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
40%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 17, 12:25 AM CDTSevere Thunderstorm WarningSJTCoke, Irion, Tom Green65 min
Mar 17, 1:13 AM CDTSevere Thunderstorm WarningSJTColeman, Concho, Runnels, Tom Green47 min
Mar 17, 1:59 AM CDTSevere Thunderstorm WarningSJTBrown, Callahan, Coleman, Concho, McCulloch, San Saba61 min
Mar 17, 2:26 AM CDTSevere Thunderstorm WarningFWDComanche, Eastland, Erath, Hamilton, Mills79 min
Mar 17, 3:38 AM CDTSevere Thunderstorm WarningFWDBosque, Erath, Hill, Hood, Johnson, Somervell67 min
Mar 17, 3:40 AM CDTSevere Thunderstorm WarningFWDDenton, Parker, Tarrant, Wise65 min
Mar 17, 4:38 AM CDTSevere Thunderstorm WarningFWDDallas, Ellis, Hill, Johnson, Tarrant82 min
Mar 17, 4:57 AM CDTSevere Thunderstorm WarningFWDFalls, Freestone, Hill, Limestone, McLennan, Navarro48 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 00:00Z, 3.4 hours before the alert went out and 253 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 00:00Z on 2021-03-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1277 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 00:00Z on 2021-03-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 158 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
1277 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
1084 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
237 m²/s²
Significant tornado parameter
0.6
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

268 
WWUS20 KWNS 170323
SEL3  
SPC WW 170323
TXZ000-171000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 23
NWS Storm Prediction Center Norman OK
1025 PM CDT Tue Mar 16 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Central and North-Central Texas

* Effective this Tuesday night and Wednesday morning from 1025 PM
  until 500 AM CDT.

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

SUMMARY...Thunderstorms are expected to develop and intensify along
a cold front pushing into west Texas.  These storms will sweep
eastward overnight across the watch area, posing a risk of damaging
winds and hail.  Isolated tornadoes are also possible.

The severe thunderstorm watch area is approximately along and 105
statute miles east and west of a line from 25 miles west southwest
of Junction TX to 50 miles north northeast of Mineral Wells 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 22...

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 450. Mean storm motion vector
25035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 16, 7:49 PM CDTSevere Thunderstorm WatchSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Roberts and 1 more7 hr
Mar 16, 9:27 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Coke, Coleman and 30 more93 min
Mar 17, 1:32 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 7 more118 min
Mar 17, 2:20 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Eastland, Erath and 6 more85 min
Mar 17, 4:04 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 25 more86 min
Mar 17, 4:37 AM CDTSevere Thunderstorm WatchSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 30 more5 hr
Mar 17, 4:38 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Dallam, Deaf Smith, Gray, Hansford and 11 more6 hr
Mar 17, 6:40 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Delta and 16 more95 min
Mar 17, 8:43 AM CDTTornado WatchSPCAngelina, Nacogdoches, Sabine, San Augustine, Shelby4 hr
Mar 17, 11:35 AM CDTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Galveston, Hardin, Harris and 10 more85 min
Mar 17, 11:53 AM CDTTornado WatchSPCHardin, Jasper, Jefferson, Newton, Orange, Tyler6 hr

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.