MD 2217 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR SOUTHWESTERN INTO CENTRAL NEBRASKA…WESTERN KANSAS
Mesoscale Discussion 2217
NWS Storm Prediction Center Norman OK
1204 PM CDT Tue Oct 03 2023
Areas affected…southwestern into central Nebraska…western Kansas
Concerning…Severe potential…Watch likely
Valid 031704Z – 031900Z
Probability of Watch Issuance…80 percent
SUMMARY…Increasing strong thunderstorm development is likely
within the next few hours, with the gradual evolution of an
intensifying and organizing squall line possible by 3-5 PM CDT
across south central Nebraska into western Kansas.
DISCUSSION…Stronger mid-level height falls have already overspread
much of the northern into central Great Plains. However, one
significant short wave perturbation, embedded within the large-scale
troughing emerging from the Intermountain West, is still in the
process of migrating across and northeast of the southern Colorado
Rockies, with a 50-60 kt southwesterly 500 mb jet streak now nosing
northeast of the Raton Mesa vicinity. Large-scale forcing for ascent
downstream of this perturbation may already be contributing to
ongoing increasing thunderstorm development, and latest model output
suggests that a substantive further increase in storms is likely by
20-22Z, if not a bit earlier.
Strongest boundary-layer destabilization is becoming focused
near/east of a weak low within lee surface troughing, across the
eastern Colorado border vicinity through western Kansas and
southwestern Nebraska. This is being supported by low-level
moisture advection and steepening lapse rates aided by insolation
beneath the leading edge of mid-level cooling. Mixed-layer CAPE
already appears to be increasing in excess of 1000 J/kg within this
corridor, and this could approach 2000 J/kg by late afternoon, as it
tends to advect northeastward and eastward through south central
Nebraska and western Kansas. This should provide support for the
greatest concentration of stronger thunderstorm development, which
may include the eventual evolution of an organizing squall line with
increasing potential to produce strong wind gusts, in addition to
severe hail. A few relatively brief tornadoes may also be possible.
..Kerr/Grams.. 10/03/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…ICT…GID…LBF…DDC…GLD…
LAT…LON 39940251 40910115 41590030 41179819 39819884 38339921
37060045 38840140 39940251
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