Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 1106

June 25, 2021Ellis County, Roger Mills County, Oklahoma; 9 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2021, 11:36 PM CDT for Ellis County, Roger Mills County, Oklahoma; 9 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jun 25, 2021, 11:36 PM CDT (04:36 UTC)
Expired
Jun 26, 2021, 1:00 AM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 318

Counties Ellis County, OK, Roger Mills County, OK, Armstrong County, TX, Carson County, TX, Castro County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Randall County, TX, Swisher County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 55 km from the middle of the area, began a volume at 04:36 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 4.6 hours before the alert went out and 54 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 2021-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 957 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 2021-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 295 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
957 J/kg
Mixed-layer CIN
-173 J/kg
Mixed-layer LCL
1729 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
295 m²/s²
0-3 km storm-relative helicity
439 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

505 
ACUS11 KWNS 260436
SWOMCD
SPC MCD 260436 
OKZ000-TXZ000-260600-

Mesoscale Discussion 1106
NWS Storm Prediction Center Norman OK
1136 PM CDT Fri Jun 25 2021

Areas affected...Texas Panhandle into western Oklahoma

Concerning...Severe Thunderstorm Watch 318...

Valid 260436Z - 260600Z

The severe weather threat for Severe Thunderstorm Watch 318
continues.

SUMMARY...Isolated hail/wind remain possible with thunderstorms into
the early-morning hours.

DISCUSSION...Strong convection has struggled to spread appreciably
east across ww318 before gradually weakening. This is possibly due
to some remaining inhibition across central OK. Thunderstorms have
repeatedly developed upstream where lapse rates are steepest across
the High Plains. Recently, convection has tended to focus
along/behind the cold front as it drops south across the Panhandle.
These trends may continue for some time as greater reservoir of
buoyancy currently extends from the TX South Plains into extreme
southwestern OK. With southerly 1km AGL flow into this activity, new
updrafts remain likely across the southern TX Panhandle. With time
the front should sag into western OK and this elongated corridor of
convection should progress across much of the western portions of
ww318, but not before the watch expires.

..Darrow.. 06/26/2021

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

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

LAT...LON   34690285 36409941 36059894 35090029 34270230 34690285

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 25, 8:49 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Custer, Dewey, Greer, Harmon and 3 more86 min
Jun 25, 11:42 PM CDTMesoscale DiscussionSPCCraig, Nowata, Osage, Ottawa, Washington63 min
Jun 25, 11:59 PM CDTSevere Thunderstorm WatchSPCBeckham, Blaine, Caddo, Canadian, Cleveland, Custer and 11 more5 hr
Jun 26, 1:53 AM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Comanche, Custer, Grady and 7 more67 min
Jun 26, 12:59 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Garvin and 12 more2 hr
Jun 26, 3:27 PM CDTMesoscale DiscussionSPCHarmon2 hr
Jun 26, 3:48 PM CDTSevere Thunderstorm WatchSPCCaddo, Carter, Comanche, Cotton, Garvin, Grady and 10 more9 hr
Jun 26, 6:27 PM CDTMesoscale DiscussionSPCComanche, Cotton, Grady, Jackson, Jefferson, McClain and 2 more93 min
Jun 26, 4:58 PM CDTSevere Thunderstorm WatchSPCBailey, Briscoe, Castro, Deaf Smith, Hale, Hall and 6 more8 hr

Nearby

Mesoscale Discussions in Texas, 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.