ACUS11 KWNS 131938
SWOMCD
SPC MCD 131938=20
OKZ000-TXZ000-132145-

Mesoscale Discussion 0399
NWS Storm Prediction Center Norman OK
0238 PM CDT Mon Apr 13 2026

Areas affected...portions of northwest Texas into central Oklahoma

Concerning...Severe potential...Watch possible=20

Valid 131938Z - 132145Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated to widely scattered thunderstorm development is
possible along a dryline this afternoon. Any sustained storms that
are able to develop will bring the potential for all severe hazards,
with the primary threat large to very large hail.

DISCUSSION...Latest surface observations depict a dryline extending south-southwestward across western Oklahoma and northwest Texas. An
area of deepening cumulus is noted in recent visible satellite
imagery across portions of the Texas Rolling Plains where convective temperatures are beginning to be reached amid strong diurnal heating
and deep boundary layer mixing behind the dryline. Within the warm
sector, mid-80s temperatures amid mid/upper 60s F dewpoints and
steep mid-level lapse rates (per 18Z LMN special sounding) are
contributing to 2000-3000 J/kg MLCAPE.=20

While upper-level forcing is forecast to remain modest at best,
30-40 kts of effective bulk shear amid a belt of enhanced mid-level
flow (40+ kts at 4-5 km AGL per regional VWPs) will support
supercells capable of all hazards. The primary threat with any
storms that do develop is expected to be large to very large hail to
2-3+ inches in diameter, which is supported by recent mesoanalysis
that indicates ample buoyancy within the hail growth zone and SHIP
values of 2+. The tornado threat remains somewhat more conditional
on a storm persisting into the evening hours when a strengthening of
the nocturnal low-level jet will yield increasing low-level SRH and
clockwise hodograph curvature.

While the timing of potential convective initiation and subsequent
storm coverage remain somewhat uncertain, a watch will likely be
needed should initiation appear imminent given the conditionally
favorable warm sector environment.

..Chalmers/Hart.. 04/13/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5Ao1ekW08VJo2yu-z8qWfNS6AhU84_hlHQQsl7BSx5H-JAaHO6JP27un18VuUyOcVNg9q7XJf= oAT0tDroLtJclC6QqE$ for graphic product...

ATTN...WFO...TSA...FWD...OUN...SJT...

LAT...LON 31590023 31890044 32320043 32949998 33669938 34289902
35339860 35939814 36329749 36409705 36339669 36019643
35239632 34189672 33509717 32699779 32109849 31679918
31549972 31590023=20

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


=3D =3D =3D
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