ZCZC SPCSWOMCD ALL
ACUS11 KWNS 271629 
SPC MCD 271629 
ARZ000-OKZ000-KSZ000-TXZ000-271730-

Mesoscale Discussion 0764
NWS Storm Prediction Center Norman OK
1129 AM CDT Thu May 27 2021

Areas affected...eastern Texas Panhandle...Oklahoma. far southern
Kansas and northwest Arkansas

Concerning...Severe potential...Watch likely 

Valid 271629Z - 271730Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorms are expected to develop across western
through central Oklahoma by early afternoon and gradually spread
east. Supercells with isolated large hail will be the initial main
threat, but isolated damaging wind and a few tornadoes are also
possible.

DISCUSSION...Latest objective analysis show the atmosphere to be
moderately to strongly unstable (2500-3000 J/kg MLCAPE) across
western through central OK supported by steep mid-level lapse rates
above rich low-level moisture with surface dewpoints in the low 70s
F. Latest trends in radar show a few showers developing within a
modest warm advection regime in the pre-frontal warm sector across
western OK. While some remnant capping may still exist, convective
inhibition should gradually weaken as temperatures rise into the low
80s F. Rap analysis data show a mid-level jet approaching this
region from the west, and effective bulk shear profiles will
gradually increase to between 40 and 50 kt through the afternoon.
This environment should support discrete supercells as the initial
storm mode with large to very large hail likely. While low-level
hodographs are not particularly large with 0-1 km storm relative
helicity between 100-150 m2/s2 isolated tornadoes cannot be ruled
out given degree of instability and a very moist boundary layer with
relatively low LCLS. Additional storms may develop along the cold
front by late afternoon across southern KS into northern OK and
these will also likely become severe.

..Dial/Hart.. 05/27/2021

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

ATTN...WFO...TSA...ICT...OUN...DDC...AMA...

LAT...LON   35579377 34959538 34920033 36260026 37099842 36719549
            35579377 

NNNN