Mesoscale Discussion 786

Issued

May 28, 2021, 2:33 PM CDT (19:33 UTC)

Expired

May 28, 2021, 4:30 PM CDT

In force

117 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch likely

Chance of a watch

80%

The San Angelo radar (KSJT), 84 km from the middle of the area, began a volume at 19:36 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.

• Severe Thunderstorm Watch 219May 28, 2:45 PM CDT
• Severe Thunderstorm Watch 220May 28, 3:40 PM CDT
• Severe Thunderstorm Watch 221May 28, 6:20 PM CDT

371 
ACUS11 KWNS 281933
SWOMCD
SPC MCD 281933 
TXZ000-NMZ000-282130-

Mesoscale Discussion 0786
NWS Storm Prediction Center Norman OK
0233 PM CDT Fri May 28 2021

Areas affected...the Permian Basin region of western Texas into the
Concho Valley and Edwards Plateau

Concerning...Severe potential...Watch likely 

Valid 281933Z - 282130Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorms are forecast to evolve in the vicinity of
the cold front over the next 1-2 hours, spreading southeastward with
time.  Risk for very large hail and locally damaging winds will
likely require WW issuance.

DISCUSSION...Latest radar loop shows isolated ongoing/elevated
storms over the Texas South Plains vicinity an eastward into the Big
Country are gradually increasing in coverage, while low cloud cover
just south of this convection, and just to the cool side of the cold
front, continues to gradually erode.  

Meanwhile, strong destabilization is underway near and south of the
front, where daytime heating of a moist (mid 60s dewpoints) boundary
layer, beneath very steep lapse rates aloft, is now yielding
mixed-layer CAPE in excess of 3000 J/kg.  

Storm development is expected to occur in the vicinity of the front
over the next 1 to 2 hours, west of ongoing strong/severe storms
occurring within WW 218, as additional heating/destabilization
occurs.  With favorably veering/increasing flow with height, storms
will rapidly organize/become severe, with very large hail likely to
be the primary risk.  Locally damaging winds will also be possible,
particularly near any organizing bands of storms which may evolve. 
Given this gradually evolving risk, WW issuance will likely be
required.

..Goss/Hart.. 05/28/2021

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

ATTN...WFO...FWD...EWX...SJT...LUB...MAF...

LAT...LON   32350335 33270258 33090137 31979888 30359890 29049990
            29300069 29900183 31110280 32350335

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

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.