Alert archive / Oklahoma / Mesoscale Discussions in 2021

Mesoscale Discussion 1251

July 10, 202124 counties in Oklahoma; Clay County, Wichita County, Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 9:21 PM CDT for 24 counties in Oklahoma; Clay County, Wichita County, Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 9:21 PM CDT (02:21 UTC)
Expired
Jul 10, 2021, 10:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 367...368
All 26 counties

Atoka County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, Love County, OK, Marshall County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Clay County, TX, Wichita County, TX

The radar

The Norman radar (KTLX), 85 km from the middle of the area, began a volume at 02:24 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.4 hours before the alert went out and 72 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, Norman, OK at 00:00Z on 2021-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2495 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, Norman, OK at 00:00Z on 2021-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
2495 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
1225 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
185 m²/s²
Significant tornado parameter
1.4
Supercell composite
14.8

Open this sounding in Storm Lab

The text

As transmitted.

540 
ACUS11 KWNS 110222
SWOMCD
SPC MCD 110221 
OKZ000-TXZ000-110345-

Mesoscale Discussion 1251
NWS Storm Prediction Center Norman OK
0921 PM CDT Sat Jul 10 2021

Areas affected...Central/South-Central/Southeast OK...Far Northwest
TX.

Concerning...Severe Thunderstorm Watch 367...368...

Valid 110221Z - 110345Z

The severe weather threat for Severe Thunderstorm Watch 367, 368
continues.

SUMMARY...Ongoing storms across central and east-central OK will
likely maintain severe intensity for the next few hours into
south-central and southeast OK.

DISCUSSION...Recent storm motion for the ongoing convective line
moving through central OK is south-southeast at 28 kt. At its
current speed, the line will move to the edge of Severe Thunderstorm
Watch 368 in Pottawatomie County around 330Z. However, it is likely
the line will begin to increase its southward progression.
Additionally, the storms are already near the edge of the watch in
Lincoln County. 

Very strong updrafts exist within this line and the cold pool
remains close to the leading edge of the strong reflectivity. These
observations, in tandem with the strong instability still in place
within the downstream air mass, suggest the storms will likely
remain strong to severe as they move into more of south-central OK
and eventually into portions of far northwest TX.

The storms ongoing across east-central OK have also experienced some
renewed vigor as the cold front moves through and the severe threat
may persist past the edge of Severe Thunderstorm Watch 367 into more
of southeast OK as well.

..Mosier/Thompson.. 07/11/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TSA...FWD...OUN...

LAT...LON   34419945 35099868 35509591 35169519 34389514 33989650
            33649859 34419945

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 10, 7:21 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Creek, Custer and 11 more84 min
Jul 10, 8:01 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Creek, Haskell, Hughes, Latimer and 8 more89 min
Jul 10, 9:35 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Coal, Comanche, Cotton and 15 more5 hr
Jul 10, 11:56 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Comanche and 12 more94 min
Jul 11, 2:46 AM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Collin, Denton, Foard and 6 more29 min
Jul 11, 11:48 AM CDTMesoscale DiscussionSPCCulberson, Loving, Reeves, Ward, Winkler, Yoakum87 min
Jul 11, 12:16 PM CDTSevere Thunderstorm WatchSPCAndrews, Borden, Cochran, Dawson, Ector, Gaines and 14 more7 hr
Jul 11, 2:33 PM CDTMesoscale DiscussionSPCAndrews, Cochran, Dawson, Ector, Gaines, Hockley and 5 more87 min
Jul 11, 3:23 PM CDTSevere Thunderstorm WatchSPCEl Paso, Hudspeth8 hr
Jul 11, 6:51 PM CDTMesoscale DiscussionSPCAnderson, Bell, Cherokee, Coke, Concho, Coryell and 22 more84 min

Nearby

Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Texas, 2021Every mesoscale discussion 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.