MD 0856 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PARTS OF SOUTH CENTRAL AND SOUTHEASTERN NEBRASKA
Mesoscale Discussion 0856
NWS Storm Prediction Center Norman OK
0606 PM CDT Mon May 20 2024
Areas affected…parts of south central and southeastern Nebraska
Concerning…Severe potential…Watch possible
Valid 202306Z – 210100Z
Probability of Watch Issuance…60 percent
SUMMARY…Scattered strong thunderstorm development is initiating
across the region and probably will persist into mid/late evening.
A few supercells are possible, primarily posing a risk for large
hail.
DISCUSSION…Deepening convective development is underway where
boundary-layer destabilization has become maximized in a corridor
from near the Hastings/Kearney vicinity into the Greater Omaha area.
This is in advance of a slowly southeastward advancing cold front,
where lower/mid-tropospheric warming across much of the central
Great Plains may be offsetting weakening of inhibition associated
with insolation. Still, roughly to the north of the Kansas/Nebraska
border, temperatures in the 700-500 mb layer remain cooler relative
to areas to south, and it appears inhibition is weak enough to allow
for intensifying thunderstorm development during the next few hours.
Mid/upper support for upward vertical motion remains uncertain, but
strong southwesterly flow in mid/upper levels is contributing to
sufficient deep-layer shear for supercell development. With
mixed-layer CAPE in excess of 2000 J/kg beneath steep mid-level
lapse rates, stronger storms may pose an initial risk for severe
hail.
Although boundary-layer cooling will contribute to increasing
inhibition into and after sunset, modest strengthening of southerly
850 mb flow and associated warm advection may maintain stronger
cells into mid/late evening.
..Kerr.. 05/20/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…OAX…GID…
LAT…LON 40829950 41519778 41609607 40759563 40129661 39959878
40219958 40829950