ZCZC SPCSWOMCD ALL
ACUS11 KWNS 191346 
SPC MCD 191346 
TXZ000-191515-

Mesoscale Discussion 0686
NWS Storm Prediction Center Norman OK
0846 AM CDT Wed May 19 2021

Areas affected...Portions of deep south TX

Concerning...Severe Thunderstorm Watch 191...

Valid 191346Z - 191515Z

The severe weather threat for Severe Thunderstorm Watch 191
continues.

SUMMARY...Damaging winds should remain the primary threat with a
line of storms moving eastward this morning.

DISCUSSION...A small, organized bow is present across parts of deep
south TX this morning, moving eastward around 35-40 kt. Based on its
current speed, this line of storms should approach the coast within
the next 1 to 1.5 hours (by 15Z/10 AM CDT). A very deep, moist
low-level airmass was observed on the 12Z BRO sounding, with a mean
mixing ratio of 19.1 g/kg. The presence of modestly steepened
mid-level lapse rates across this region is also contributing to
MLCAPE of 2500-3000 J/kg downstream of the ongoing convection. The
mid-level flow downstream from an upper low centered over the
southern/central High Plains is not overly strong this morning, but
around 30-35 kt of effective bulk shear should be enough to support
continued storm organization. Given the linear nature of the ongoing
convection and rather favorable thermodynamic environment, damaging
wind gusts will likely be the primary severe threat. Around 100
m2/s2 of 0-1 km SRH also suggests that a brief QLCS tornado embedded
within the line remains a possibility.

..Gleason.. 05/19/2021

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

ATTN...WFO...CRP...BRO...

LAT...LON   26219855 26799825 27369855 27399773 27239728 26879730
            26469717 25999710 25889753 26029782 25999803 26089840
            26219855 

NNNN