Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 186

March 16, 202112 counties in Oklahoma; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 16, 2021, 6:02 PM CDT for 12 counties in Oklahoma; 13 counties in Texas. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Mar 16, 2021, 6:02 PM CDT (23:02 UTC)
Expired
Mar 16, 2021, 7:30 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%
All 25 counties

Beckham County, OK, Caddo County, OK, Comanche County, OK, Cotton County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Briscoe County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Dickens County, TX, Foard County, TX, Hall County, TX, Hardeman County, TX, King County, TX, Knox County, TX, Motley County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 55 km from the middle of the area, began a volume at 23:01 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, 11.0 hours before the alert went out and 217 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 2021-03-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-03-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939587897117Sfc1 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
3067 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

990 
ACUS11 KWNS 162303
SWOMCD
SPC MCD 162302 
OKZ000-TXZ000-170030-

Mesoscale Discussion 0186
NWS Storm Prediction Center Norman OK
0602 PM CDT Tue Mar 16 2021

Areas affected...Southwest Oklahoma and the eastern Texas Panhandle

Concerning...Severe potential...Watch possible 

Valid 162302Z - 170030Z

Probability of Watch Issuance...40 percent

SUMMARY...A few strong to severe storms may develop across the Texas
Panhandle and southwestern Oklahoma this evening. If storms can
intensify, a risk for strong winds and large hail will be possible.
Trends will be monitored for a possible watch.

DISCUSSION...Recent visible satellite imagery showed deepening
convective towers along a dryline and south of a warm front in the
eastern Texas Panhandle. Storm initiation appears possible along
this corridor over the next few hours as inhibition is diminished
from increasing lift ahead of a compact shortwave trough ejecting
east across the Rockies, and rapid low-level theta E advection
across central Texas/Oklahoma. 22z SPC mesoanalysis/surface obs show
low 50s and upper 40s dewpoints streaming northward ahead of the
developing convection, resulting in 500-1500 J/kg of MLCAPE.
Deep-layer shear of 40-50 kt, orthogonal to the dryline, will favor
a somewhat high based supercellular mode with a risk of large hail
and damaging wind gusts. 

If storms can develop, there is some uncertainty on the character of
the severe threat into south-central Oklahoma where greater moisture
and instability are likely to develop this evening. A watch may be
needed, but is conditional upon strong storm development/longevity.

..Lyons/Hart.. 03/16/2021

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

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

LAT...LON   35559921 35569852 35219773 34639756 34269792 34139813
            33879880 33639939 33389990 33310034 33240059 33420085
            33680098 34270115 34520138 34790087 35339988 35559921

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 16, 6:46 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Blaine, Craig, Creek, Custer and 21 more89 min

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.