ACUS11 KWNS 152256
SWOMCD
SPC MCD 152256
MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-160030-

Mesoscale Discussion 0455
NWS Storm Prediction Center Norman OK
0556 PM CDT Wed Apr 15 2026

Areas affected...South central Oklahoma into southwest Missouri

Concerning...Tornado Watch 121...

Valid 152256Z - 160030Z

The severe weather threat for Tornado Watch 121 continues.

SUMMARY...Occasional large hail will be the main threat, though an
isolated tornado or two remain possible.

DISCUSSION...Severe storms are ongoing from extreme northeast OK
into southwest MO, with new storm development occurring a couple of
counties to the south near the northwest corner of AR.  Farther
southwest, extensive anvil cirrus has overspread much of
southern/central OK east of the dryline, where mesonet observations
show surface temperature decreases of 3-6 F the past few hours.
Similarly, persistent clouds farther east have also limited surface
temperatures into the low-mid 70s, though forecast soundings suggest
the environment is not strongly capped.

Regional VWPs show sufficient deep-layer shear for supercells,
though hodographs remain relatively straight with only modest
low-level curvature.  A modest increase in low-level shear this
evening could still support an isolated tornado threat, but the
messy convective modes and sub-optimal distribution of clouds casts
doubt on the persistence and magnitude of the tornado threat.  A
small patch of surface heating in northern OK could support
additional storm development, with a more E-W orientation to that
part of the boundary suggesting a likelihood of storm interactions
and a cluster mode (if additional storms form).  Overall, if present
trends continue a sizable portion of the tornado watch could be
cancelled for central OK by 23-00z.

..Thompson.. 04/15/2026

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

ATTN...WFO...SGF...EAX...TSA...ICT...FWD...OUN...

LAT...LON   36559366 35799456 34679580 33969681 33939746 34149801
            34839797 36159758 36659698 37149576 38019453 38359363
            38429309 37589309 36559366

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN