Alert archive / Arkansas / Tornado Watches in 2021

Tornado Watch 123

April 29, 202123 counties in Arkansas; 21 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 29, 2021, 2:01 AM CDT for 23 counties in Arkansas; 21 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 29, 2021, 2:01 AM CDT (07:01 UTC)
Expired
Apr 29, 2021, 8:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 44 counties

Clark County, AR, Conway County, AR, Faulkner County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Little River County, AR, Logan County, AR, Lonoke County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, White County, AR, Yell County, AR, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 135 km from the middle of the area, began a volume at 07:02 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
30%
One or more EF2 to EF5 tornadoes
10%
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
20%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 29, 4:35 AM CDTFlash Flood WarningLZKCleburne, Independence, Stone, Van Buren, White4 hr
Apr 29, 6:01 AM CDTFlash Flood WarningLZKGarland, Montgomery, Perry, Pike, Saline4 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

Shreveport, LA (KSHV), launched 00:00Z, 7.0 hours before the alert went out and 138 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, Shreveport, LA at 00:00Z on 2021-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 976 joules per kilogram.LCLLFCEL10008507005003002001001 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, Shreveport, LA at 00:00Z on 2021-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 169 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
976 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1188 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
169 m²/s²
0-3 km storm-relative helicity
258 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.0

Open this sounding in Storm Lab

The text

As transmitted.

043 
WWUS20 KWNS 290659
SEL3  
SPC WW 290659
ARZ000-OKZ000-TXZ000-291300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 123
NWS Storm Prediction Center Norman OK
200 AM CDT Thu Apr 29 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central and southwestern Arkansas
  Extreme southeastern Oklahoma
  Northeast Texas

* Effective this Thursday morning from 200 AM until 800 AM CDT.

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

SUMMARY...A swath of convection, with occasional strong-severe
thunderstorms, will pose a threat for intermittent severe wind and
hail.  Embedded supercells and mesovortices may offer a tornado
threat as well, in a favorably sheared and moist environment.

The tornado watch area is approximately along and 60 statute miles
east and west of a line from 40 miles west southwest of Tyler TX to
45 miles north of Little Rock AR. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU3).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 121...WW 122...

AVIATION...Tornadoes and 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 25030.

...Edwards

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 7:55 PM CDTTornado WatchSPCClark, Cleburne, Conway, Crawford, Faulkner, Franklin and 18 more6 hr
Apr 28, 9:19 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Howard, Little River, Logan, Montgomery and 5 more116 min
Apr 28, 10:22 PM CDTMesoscale DiscussionSPCCleburne, Conway, Craighead, Crittenden, Cross, Faulkner and 22 more113 min
Apr 29, 1:09 AM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Logan, Miller, Montgomery and 6 more2 hr
Apr 29, 3:14 AM CDTMesoscale DiscussionSPCClay, Craighead, Greene3 hr
Apr 28, 7:01 PM CDTMesoscale DiscussionSPCBastrop, Bexar, Caldwell, Comal, Gonzales, Guadalupe and 4 more89 min
Apr 28, 7:31 PM CDTMesoscale DiscussionSPCCallahan, Coleman, Collin, Comanche, Cooke, Dallas and 24 more119 min
Apr 28, 9:13 PM CDTMesoscale DiscussionSPCBastrop, Bexar, Caldwell, Colorado, Comal, Fayette and 4 more92 min
Apr 28, 10:22 PM CDTTornado WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 27 more7 hr
Apr 28, 11:03 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 37 more117 min

Nearby

Tornado Watches in Arkansas, 2021Tornado Watches in Texas, 2021Every tornado 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.