Alert archive / Texas / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 48

March 24, 202124 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Mar 24, 2021, 4:59 PM CDT for 24 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Mar 24, 2021, 4:59 PM CDT (21:59 UTC)
Expired
Mar 24, 2021, 10:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 24 counties

Camp County, TX, Collin County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Gregg County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Morris County, TX, Parker County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Smith County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Wise County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 100 km from the middle of the area, began a volume at 21:58 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
40%
One or more hailstones of 2 inches or more
40%
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
Mar 24, 5:39 PM CDTSevere Thunderstorm WarningFWDDallas, Hunt, Kaufman, Rockwall66 min
Mar 24, 6:49 PM CDTSevere Thunderstorm WarningSHVFranklin, Wood41 min
Mar 24, 6:50 PM CDTSevere Thunderstorm WarningFWDRains24 min
Mar 24, 6:58 PM CDTSevere Thunderstorm WarningSHVWood47 min
Mar 24, 7:25 PM CDTSevere Thunderstorm WarningFWDHopkins40 min
Mar 24, 7:26 PM CDTSevere Thunderstorm WarningSHVFranklin, Red River, Titus49 min
Mar 24, 8:40 PM CDTSevere Thunderstorm WarningFWDDenton, Parker, Tarrant, Wise65 min
Mar 24, 8:48 PM CDTSevere Thunderstorm WarningFWDJack, Wise42 min
Mar 24, 9:12 PM CDTSevere Thunderstorm WarningFWDCooke, Montague51 min
Mar 24, 9:29 PM CDTSevere Thunderstorm WarningFWDDenton61 min
Mar 24, 9:37 PM CDTTornado WarningFWDDenton32 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, 10.0 hours before the alert went out and 81 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 2021-03-24Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2021-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 182 square meters per square second.1939587897Sfc1 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
1705 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
182 m²/s²
0-3 km storm-relative helicity
362 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

827 
WWUS20 KWNS 242155
SEL8  
SPC WW 242155
TXZ000-250300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 48
NWS Storm Prediction Center Norman OK
500 PM CDT Wed Mar 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  North and northeast Texas

* Effective this Wednesday afternoon and evening from 500 PM
  until 1000 PM CDT.

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

SUMMARY...Multiple supercells are expected to develop
north-northeast from north-central Texas this evening. Large hail is
expected to be the primary hazard.

The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 30 miles northwest of
Fort Worth TX to 50 miles southeast of Paris 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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 47...

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
22040.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 3:22 PM CDTMesoscale DiscussionSPCAnderson, Bell, Bosque, Brown, Burnet, Comanche and 32 more2 hr
Mar 24, 4:38 PM CDTTornado WatchSPCBell, Bosque, Brown, Burnet, Comanche, Coryell and 21 more5 hr
Mar 24, 6:10 PM CDTMesoscale DiscussionSPCBell, Bosque, Brown, Burnet, Comanche, Concho and 31 more65 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.