102
ACUS11 KWNS 220339
SWOMCD
SPC MCD 220339
TNZ000-ARZ000-MSZ000-OKZ000-220545-

Mesoscale Discussion 0884
NWS Storm Prediction Center Norman OK
1039 PM CDT Tue May 21 2024

Areas affected...east central Oklahoma into central Arkansas

Concerning...Tornado Watch 283...

Valid 220339Z - 220545Z

The severe weather threat for Tornado Watch 283 continues.

SUMMARY...Isolated supercell thunderstorm development persists and
may continue to spread eastward across and east the Mississippi
River through 06-07Z.  These may pose a risk for severe hail and
locally strong gusts.  The potential for tornadoes may now be low
enough that a new severe weather watch does not appear needed, but
trends will continue to be monitored.

DISCUSSION...Ahead of a cold front advancing southeastward across
the Ozark Plateau, isolated supercell development is being
maintained near the southern periphery of broad mid-level troughing
still slowly progressing to the east of the southern Rockies.
Forcing for ascent is being aided by weak low-level warm advection
near the nose of an increasingly suppressed plume of elevated
mixed-layer air, where steep lapse rates are contributing to CAPE up
to around 3000 J/kg.  Deep-layer mean flow on the order of 40-50 kt
remains strongly sheared as it has taken on an increasingly westerly
component in the wake of the primary short wave trough shifting
through the Upper Midwest.  It is possible pre-frontal low-level
moistening and destabilization could support the continued eastward
spread of ongoing storms into/through portions of the Mid South by
06-07Z.

..Kerr.. 05/22/2024

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

ATTN...WFO...MEG...LZK...TSA...

LAT...LON   35599490 35449278 35628960 34529050 34549385 34769543
            35599490