ACUS11 KWNS 190311
SWOMCD
SPC MCD 190310=20
OKZ000-190445-

Mesoscale Discussion 0781
NWS Storm Prediction Center Norman OK
1010 PM CDT Mon May 18 2026

Areas affected...portions of northern Oklahoma

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

Valid 190310Z - 190445Z

Probability of Watch Issuance...60 percent

SUMMARY...The severe threat may increase over northern OK over the
next few hours as storms back-build southwestward along a southward
drifting cold front. Severe gusts are the main threat, though an
instance or two of hail or a tornado are possible. Convective trends
are being monitored for the need of a WW issuance.

DISCUSSION...Robust multicellular convection, with a history of
measured severe gusts, has been steadily back-building
west-southwestward along and immediately behind a southward sagging
cold front. Despite weak upper support, strong low-level convergence
has been supporting persistent convective development, especially
given a 50 kt southerly low-level jet bisecting the cold front
nearly perpendicularly. Ahead of the front, upper 60s F surface
dewpoints beneath 8-9 C/km mid-level lapse rates are yielding 3000+
J/kg MLCAPE per the 00Z OUN/LMN soundings and 02Z mesoanalysis.
These same data sources also depict sizeable low-level hodographs
with 300 m2/s2 effective SRH and 40+ kts of effective bulk shear. As
such, the ambient environment clearly supports severe potential.

The primary uncertainty is how far southwest convection will
initiate along the southward-sagging front, and the timing for
storms to propagate into OK. The current thinking is that storms
capable of severe gusts will eventually propagate southward into
north-central and northeast OK. An instance or two of severe hail
could accompany the stronger storm cores, and a tornado cannot be
ruled out if a robust updraft can outpace the cold front. Convective
trends will continue to be monitored for convective propagation into
OK.

..Squitieri/Mosier.. 05/19/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!6IIaYJ_xwx7sFpAXlzpOG3-7WJAb9y1i5dXtVevvKec16gKX1THy7TL2D-MYe9J91buyyQVrw= BZn_8gKlKIJgKcnPyM$ for graphic product...

ATTN...WFO...TSA...OUN...

LAT...LON 36779919 36929821 36999709 36969623 36739582 36449572
36099589 35879664 35809745 35909809 36089856 36429904
36779919=20

MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


=3D =3D =3D
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