Mesoscale Discussion 0874
NWS Storm Prediction Center Norman OK
0215 PM CDT Tue May 21 2024
Areas affected...Eastern KS...Western MO...Northeast OK...Far
Northwest AR
Concerning...Severe potential...Watch likely
Valid 211915Z - 212115Z
Probability of Watch Issuance...80 percent
SUMMARY...Severe thunderstorm development is anticipated this
afternoon from eastern Kansas into western Missouri, northeast
Oklahoma, and far northwest Arkansas. All severe hazards are
possible and a watch will likely be needed soon.
DISCUSSION...Visible satellite imagery shows increasingly agitated
cumulus ahead of a surface trough extending arcing southeastward
into northeast KS and then back southwestward from east-central KS
through north-central OK. The airmass preceding this boundary is
characterized by temperatures in the mid to upper 80s, dewpoints in
the upper 60s/low 70s, and strong buoyancy. Recent mesoanalysis
estimates MLCAPE around 2500 J/kg is currently in place, with the
18Z TOP sounding sampling 3100 J/kg. This same sounding revealed
that much of the convective inhibition has been eroded, although the
warm-layer between 800-700 mb could still result in updrafts
struggling to mature. The general expectation is that additional
heating should help diminish the effect of that warm layer even
more, with both increasing large-scale ascent and convergence along
the boundary providing the lift needed for convective initiation.
This initiation will likely begin in the northeast KS/Kansas City
vicinity before expanding southward/southwestward over time.
Deep-layer shear is strong enough to support organized
updrafts/supercells, with all severe hazards possible. Given the
strong buoyancy, most prominent hazard appears to be large to very
large hail. Strong downdrafts appear possible as well. Low-level
flow is a bit weaker in this region that areas farther south,
resulting in a modest weakness in the hodograph, which could act to
inhibit tornadogenesis. However, given the likely organized
character to the storms, there is still some tornado potential with
any discrete storm. A watch will likely be needed soon to address
these hazards.
..Mosier/Guyer.. 05/21/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SGF...EAX...TSA...TOP...ICT...
LAT...LON 39999502 40479441 40339322 38629301 36579381 35999517
36259658 37979582 39999502