Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 1438

August 7, 20217 counties in Kansas; 6 counties in Oklahoma; 17 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2021, 8:20 PM CDT for 7 counties in Kansas; 6 counties in Oklahoma; 17 counties in Texas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Aug 7, 2021, 8:20 PM CDT (01:20 UTC)
Expired
Aug 7, 2021, 9:15 PM CDT
In force
55 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 412
All 30 counties

Barber County, KS, Clark County, KS, Comanche County, KS, Harper County, KS, Kiowa County, KS, Meade County, KS, Pratt County, KS, Beaver County, OK, Ellis County, OK, Harper County, OK, Texas County, OK, Woods County, OK, Woodward County, OK, Armstrong County, TX, Bailey County, TX, Carson County, TX, Castro County, TX, Deaf Smith County, TX, Gray County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Moore County, TX, Ochiltree County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Sherman County, TX

The radar

The Amarillo radar (KAMA), 156 km from the middle of the area, began a volume at 01:23 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.3 hours before the alert went out and 156 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 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2016 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 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
2016 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
2104 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

218 
ACUS11 KWNS 080121
SWOMCD
SPC MCD 080120 
KSZ000-OKZ000-TXZ000-NMZ000-080215-

Mesoscale Discussion 1438
NWS Storm Prediction Center Norman OK
0820 PM CDT Sat Aug 07 2021

Areas affected...Parts of the Texas Panhandle...northwestern
Oklahoma...southwestern Kansas

Concerning...Severe Thunderstorm Watch 412...

Valid 080120Z - 080215Z

The severe weather threat for Severe Thunderstorm Watch 412
continues.

SUMMARY...Remaining valid portions of Severe Thunderstorm Watch 412
could be locally extended in time for an hour or two.  However, the
risk for severe weather appears to be waning, and another watch is
not anticipated.

DISCUSSION...Nocturnal southerly low-level intensification should
commence along/east of surface troughing across the Texas South
Plains and Panhandle into southwest Kansas during the next few
hours.  This could contribute to maintenance of thunderstorm
activity into late evening, but this probably will largely become
focused to the cool side of a convective outflow enhanced front
which is forecast to stall near/north of Medicine Lodge, KS into
areas near/southwest of Amarillo.  To the warm side of this surface
front, increasing inhibition associated with boundary-layer cooling
beneath warm elevated mixed-layer, near/south of the southern
periphery of mid-level troughing turning eastward across the central
Great Plains, likely will result in further waning of convective
development.

..Kerr.. 08/08/2021

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

ATTN...WFO...ICT...OUN...DDC...LUB...AMA...ABQ...

LAT...LON   35630233 36480254 36820134 37529991 37739953 38009897
            37269785 35690013 33630329 35630233

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 9:35 PM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Geary, Jackson, Jefferson and 7 more85 min
Aug 7, 11:19 PM CDTMesoscale DiscussionSPCDoniphan86 min
Aug 7, 11:42 PM CDTMesoscale DiscussionSPCButler, Chase, Greenwood, Harper, Harvey, Lyon and 2 more93 min

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Kansas, 2021Mesoscale 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.