MD 0991 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF SOUTH-CENTRAL TEXAS AND THE TEXAS HILL COUNTRY
Mesoscale Discussion 0991
NWS Storm Prediction Center Norman OK
0203 PM CDT Mon May 26 2025
Areas affected...portions of south-central Texas and the Texas Hill
Country
Concerning...Severe potential...Watch likely
Valid 261903Z - 262030Z
Probability of Watch Issuance...80 percent
SUMMARY...Supercells are expected to develop early this afternoon
along a rapidly modifying remnant outflow across south-central TX.
Large to very large hail, damaging gusts and some tornado risk are
likely. A WW is likely this afternoon.
DISCUSSION...Across portions of south-central TX and the western
Hill Country, early afternoon observations showed strong diurnal
heating was allowing for rapid air mass recovery along and north of
a remnant outflow boundary. A wavy dryline was also analyzed from
the TX Big Bend region northwestward into southeastern NM and should
continue to slowly mix eastward through the early afternoon. As
broad scale ascent from a southern stream shortwave trough
overspreads these surface features, a combination of low-level
convergence and near convective temperatures should result in
scattered thunderstorm development this afternoon.
As surface temperatures near 90 degrees, initial incipient
convective attempts were evident from visible imagery along the
boundary. The warm temperatures with low 70-s F dewpoints beneath
8-9 C/km mid-level lapse rates are allowing for large buoyancy with
3000+ J/kg of MLCAPE. Supercell wind profiles are in place and
should continue to strengthen into this evening with the approach of
the shortwave trough. With supercells expected in moderate shear and
strong buoyancy, large to very large hail (2.5-3.5 in) is likely
with a few intense storms. Some tornado risk may also develop with
backed low-level flow near the outflow, and any supercells able to
persist near the boundary. Damaging wind potential may increase as
storms begin to cluster.
Severe potential should increase rapidly early this afternoon as
storms develop along the dryline and near the modified outflow.
Storms moving northeastward will mainly pose a hail risk as they
move deeper into the cooler surface air mass, with surface-based
storms likely farther south and west. A weather watch will likely be
needed.
..Lyons/Guyer.. 05/26/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...EWX...SJT...MAF...
LAT...LON 29260084 29630147 30110157 30650163 31410237 31460236
32250181 31900010 31189855 30479818 29379823 28859868
28790029 29120052 29260084
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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