Alert archive / Oklahoma / Mesoscale Discussions in 2021

Mesoscale Discussion 1316

July 18, 202112 counties in Oklahoma; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2021, 7:21 PM CDT for 12 counties in Oklahoma; 12 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 18, 2021, 7:21 PM CDT (00:21 UTC)
Expired
Jul 18, 2021, 8:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 383
All 24 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woodward County, OK, Armstrong County, TX, Carson County, TX, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Ochiltree County, TX, Roberts County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 139 km from the middle of the area, began a volume at 00:21 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 0.4 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, Amarillo Airport, TX at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 775 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, Amarillo Airport, TX at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
775 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1818 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

650 
ACUS11 KWNS 190022
SWOMCD
SPC MCD 190021 
OKZ000-TXZ000-190145-

Mesoscale Discussion 1316
NWS Storm Prediction Center Norman OK
0721 PM CDT Sun Jul 18 2021

Areas affected...Eastern Texas Panhandle...Western Oklahoma

Concerning...Severe Thunderstorm Watch 383...

Valid 190021Z - 190145Z

The severe weather threat for Severe Thunderstorm Watch 383
continues.

SUMMARY...Strong/severe thunderstorms will propagate south across
ww383 over the next several hours. Hail/wind remain possible.

DISCUSSION...Latest water-vapor imagery depicts a disturbance that
has progressed across western KS and is dropping south across the OK
Panhandle. This feature appears partly responsible for ongoing
convection that has grown upscale into a disorganized MCS that
currently stretches from the northern TX Panhandle-western/central
OK. Surface analysis suggests a disjointed boundary currently
extends from southeast OK-north of Pauls Valley-HBR-AMA, with the
western portion of this boundary advancing south, along with
convection, at roughly 15-20kt. Strongest updrafts are likely
producing hail with this broad cluster of convection and there is
some risk for wind with more organized, bowing line segments.
Overall, this complex of storms should propagate across the eastern
TX Panhandle toward the Red River over the next 1-3 hours.

..Darrow.. 07/19/2021

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

ATTN...WFO...OUN...AMA...

LAT...LON   36630188 36659846 34759822 34750156 36630188

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.