Mesoscale Discussion 165

Issued

Mar 13, 2021, 1:52 PM CST (19:52 UTC)

Expired

Mar 13, 2021, 3:45 PM CST

In force

113 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...tornado watch likely

Chance of a watch

95%

Counties Harmon County, OK, Armstrong County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Donley County, TX, Floyd County, TX, Gray County, TX, Hall County, TX, Hemphill County, TX, Hutchinson County, TX, Motley County, TX, Roberts County, TX, Wheeler County, TX

The Amarillo radar (KAMA), 96 km from the middle of the area, began a volume at 19:52 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.

• Tornado Watch 20Mar 13, 2:25 PM CST

832 
ACUS11 KWNS 131953
SWOMCD
SPC MCD 131952 
OKZ000-TXZ000-132145-

Mesoscale Discussion 0165
NWS Storm Prediction Center Norman OK
0152 PM CST Sat Mar 13 2021

Areas affected...eastern portions of the TX Panhandle and TX South
Plains into far western OK

Concerning...Severe potential...Tornado Watch likely 

Valid 131952Z - 132145Z

Probability of Watch Issuance...95 percent

SUMMARY...The severe threat will continue to increase through
mid/late afternoon. Thunderstorms are expected to develop and move
into the discussion area around 22z. Supercells capable of producing
strong tornadoes, very large hail and damaging wind gusts are
expected and a watch will be issued in the next hour.

DISCUSSION...A thick cirrus shield oriented southwest to northeast
across the TX South Plains/Panhandle vicinity has limited stronger
surface heating somewhat this afternoon. Nevertheless, low level
moisture has continued to increase across the region on strong
southeasterly low level flow. Steep midlevel lapse rates of 8.0-8.5
C/km are already in place over the region and are contributing to
1000-1500 J/kg MLCAPE. Regional VWP data continues to show favorable
shear for supercell development. While low level hodographs remain
somewhat small, elongated profiles above 2-3 km indicate favorable
conditions for very large hail amid steep lapse rates, and hail
greater than 2 inches in diameter appears likely with the strongest
cells. Fast-moving cells and strong low level winds also will
support damaging wind gusts. 

A narrow corridor has developed from roughly Floyd County TX to
Wheeler County TX where thinner cirrus has allowed for stronger
heating. Surface temperatures are around 5-10 degrees warmer in this
corridor per West TX Mesonet data compared to points to the west.
Weaker inhibition is noted in 19z Mesoanalysis data, along with
slightly stronger low level lapse rates. This corridor may become
more favorable for longer-tracked supercells and strong tornadoes
later this afternoon. Nevertheless, strong low level shear and a
moist, unstable environment could support tornadogenesis in any
semi-discrete cells through early evening.

..Leitman/Grams.. 03/13/2021

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

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

LAT...LON   34859971 34459976 34159994 33890030 33800065 33730113
            33810138 33920148 34050154 34820165 35550162 35910155
            35970146 36080123 36150074 36150041 36030005 35879989
            35509973 34859971

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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.