Alert archive / Oklahoma / Mesoscale Discussions in 2021

Mesoscale Discussion 1247

July 10, 202117 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 7:21 PM CDT for 17 counties in Oklahoma. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 7:21 PM CDT (00:21 UTC)
Expired
Jul 10, 2021, 8:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 367...368

Counties Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Creek County, OK, Custer County, OK, Greer County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Noble County, OK, Oklahoma County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Washita County, OK

The radar

The Norman radar (KTLX), 102 km from the middle of the area, began a volume at 00:23 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.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 0.4 hours before the alert went out and 97 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.

364 
ACUS11 KWNS 110021
SWOMCD
SPC MCD 110021 
OKZ000-110145-

Mesoscale Discussion 1247
NWS Storm Prediction Center Norman OK
0721 PM CDT Sat Jul 10 2021

Areas affected...Central/Western OK

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

Valid 110021Z - 110145Z

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

SUMMARY...Severe threat will continue across central and western OK
through the evening as thunderstorms develop along the cold front.

DISCUSSION...Recent surface analysis placed the cold front from
about 50 miles northwest of CSM to about 15 miles northwest of BVO.
Much of the activity in northeast/north-central OK has occurred
ahead of the cold front thus far, but the most recent storm
development south of END and near JWG is occurring along the wind
shift associated with the cold front. Remnant outflow boundary also
exists from just southwest of CSM to just south of JWG. 

The air mass south of the front across central and western OK is
strongly unstable and moderately sheared and severe thunderstorms
are still expected to develop southwestward along the front over the
next few hours. Some hail is possible with initial updrafts, but
quick linear development is anticipated as the outflow surges
southward, resulting in strong wind gusts as the primary threat. Low
probability tornado potential will still exist for the next few
hours, but weak low-level vertical shear show limit the overall
threat.

..Mosier.. 07/11/2021

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

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

LAT...LON   35639957 36259783 36759625 35499628 34869893 34879991
            35639957

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 10, 8:01 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Creek, Haskell, Hughes, Latimer and 8 more89 min
Jul 10, 9:21 PM CDTMesoscale DiscussionSPCAtoka, Carter, Cleveland, Coal, Comanche, Cotton and 18 more84 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

Nearby

Mesoscale Discussions in Oklahoma, 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.