ACUS11 KWNS 261729
SWOMCD
SPC MCD 261728
TXZ000-261930-

Mesoscale Discussion 0861
NWS Storm Prediction Center Norman OK
1228 PM CDT Tue May 26 2026

Areas affected...Texas Hill Country

Concerning...Severe potential...Watch likely

Valid 261728Z - 261930Z

Probability of Watch Issuance...80 percent

SUMMARY...Large hail and severe gusts will become more probable into
the afternoon. Very-large hail and a tornado or two would be
possible with any sustained supercells. A watch will eventually be
needed for parts of the Hill Country.

DISCUSSION...A line of convection continues to move eastward out of
the Trans-Pecos/Big Bend regions. Morning sounding data from Del Rio
showed a low-level dry pocket. Dewpoints had initially mixed down
into the low 60s F with the onset of daytime heating, but richer
moisture continues to advect northwestward into the Hill Country.
The current expectation is for this convection to gradually increase
as surface heating continues and the low levels moisten through the
afternoon. The strongest activity will likely remain south of the
I-10 corridor given modestly drier outflow to the north and greater
buoyancy and effective shear closer to the Rio Grande. Steep
mid-level lapse rates will promote large to very large hail,
particularly with supercells. That said, shear is somewhat marginal
for supercells and linear modes will tend to dominate. The risk for
tornadoes is nonzero, but will depend on a supercell mode near the
Rio Grande Valley (reference the KDFX VAD). With time, a greater
severe wind threat should develop as convection grows upscale. A
watch will eventually be needed, but timing of a ramp up in storm
intensity remains the primary uncertainty.

..Wendt/Gleason.. 05/26/2026

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

ATTN...WFO...EWX...SJT...MAF...

LAT...LON   29450140 29500202 29580222 29830227 30220216 30760186
            30970152 30910094 30669970 30259946 29589975 28950074
            29030083 29450140

MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN