Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 1014

June 13, 2017Beaver County, Ellis County, Roger Mills County, Oklahoma; 24 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 13, 2017, 3:14 PM CDT for Beaver County, Ellis County, Roger Mills County, Oklahoma; 24 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 13, 2017, 3:14 PM CDT (20:14 UTC)
Expired
Jun 13, 2017, 5:45 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 27 counties

Beaver County, OK, Ellis County, OK, Roger Mills County, OK, Armstrong County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Ochiltree County, TX, Roberts County, TX, Swisher County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 93 km from the middle of the area, began a volume at 20:15 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 12:00Z, 8.2 hours before the alert went out and 92 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 12:00Z on 2017-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 12:00Z on 2017-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2131 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
132 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

656 
ACUS11 KWNS 132014
SWOMCD
SPC MCD 132014 
OKZ000-TXZ000-132245-

Mesoscale Discussion 1014
NWS Storm Prediction Center Norman OK
0314 PM CDT Tue Jun 13 2017

Areas affected...Portions of the TX/OK Panhandles...TX South
Plains...and western OK

Concerning...Severe potential...Watch likely 

Valid 132014Z - 132245Z

Probability of Watch Issuance...95 percent

SUMMARY...Severe thunderstorm development will likely occur in the
21-22Z time frame, and a Severe Thunderstorm Watch will be likely.
Significant severe hail will be possible.

DISCUSSION...High-based cumulus development continues in proximity
to diurnal-heating bolstered dryline circulations from the central
OK Panhandle to western/central parts of the TX Panhandle and South
Plains. As MLCINH accompanying a warm elevated mixed layer continues
to erode, thunderstorm development will be likely in the 21-22Z time
frame, with activity spreading east-northeastward into the evening
hours east of the sharpening dryline. East of the dryline, surface
dewpoints have held in the lower/middle 60s beneath 8-9 C/km
midlevel lapse rates, yielding SBCAPE locally upwards of 3000-4000
J/kg. Furthermore, with 35-45 kt of effective shear -- enhanced by a
vertically veering wind profile and in proximity to a midlevel speed
maximum crossing the area per water vapor imagery -- sustained
supercells with significant severe hail will be likely. Some risk
for giant hail (4-inch hail) cannot be ruled out. Into the late
afternoon hours and the evening, strengthening convective outflow
with merging outflows may support isolated to widely scattered
severe wind gusts, as convection spreads into western OK. Given the
substantial buoyancy, and increase in effective SRH early this
evening coincident with the incipient stages of nocturnal decoupling
of the boundary layer, a tornado could also occur.

..Cohen/Hart.. 06/13/2017

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

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

LAT...LON   33230208 33910223 35230181 36800067 36809973 36219961
            34379992 33340050 33060161 33230208

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 13, 3:38 PM CDTSevere Thunderstorm WatchSPCBeaver, Beckham, Ellis, Greer, Harmon, Harper and 3 more7 hr
Jun 13, 6:30 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Custer, Dewey, Ellis, Greer and 6 more90 min
Jun 13, 2:09 PM CDTMesoscale DiscussionSPCBorden, Crane, Dawson, Ector, Glasscock, Howard and 5 more3 hr

Nearby

Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Oklahoma, 2017Every mesoscale discussion in 2017

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.