ACUS11 KWNS 151522
SWOMCD
SPC MCD 151522=20
IAZ000-NEZ000-151745-

Mesoscale Discussion 0445
NWS Storm Prediction Center Norman OK
1022 AM CDT Wed Apr 15 2026

Areas affected...Eastern Nebraska into much of Iowa

Concerning...Severe potential...Watch possible=20

Valid 151522Z - 151745Z

Probability of Watch Issuance...40 percent

SUMMARY...The severe risk will gradually increase and spread
eastward into this afternoon. A few instances of severe hail is the
main concern for the next few hours. While timing is uncertain, a
watch may eventually be needed for parts of the area.

DISCUSSION...Water-vapor imagery indicates a midlevel trough moving
eastward across the central Plains, preceded by around 50 kt of
southwesterly midlevel flow (per regional VWP data). An accompanying
surface low, currently analyzed over southeast NE, will track
eastward along a composite outflow/stationary front draped across
southern IA into this afternoon. Isolated elevated thunderstorms are
already evolving to the northeast of the surface low and to the
north of the boundary in eastern NE, which will pose a risk of
isolated severe hail in the near term. This activity will generally spread/develop eastward along/north of the surface boundary in
tandem with the surface low and deep-layer ascent accompanying the
midlevel trough into this afternoon. Despite the expected elevated
nature of these storms for the next several hours,
elongated/straight hodographs (40-50 kt of effective shear) and
steep midlevel lapse rates/modest buoyancy atop the boundary layer
will support transient elevated supercell structures capable of
producing severe hail.

With time, the low-level mass response accompanying the midlevel
trough and surface low will draw lower/middle 60s dewpoints
northward into central IA in the wake of ongoing convection.
Depending on the degree of diurnal heating in cloud breaks, this may
support a transition to surface-based storms into the afternoon,
with an associated risk for damaging wind gusts and large hail with
organized clusters and supercells. It is unclear if the
ongoing/morning and early-afternoon elevated storms will warrant a
watch, though current thinking is that a watch may eventually be
needed for parts of the area.

..Weinman/Gleason.. 04/15/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4RPemON4Xe7jfU0ufQMZr0babE3BgjOqk-dvfafk0veH4mg9egz00fxJ0fMnWJDSNPV2aIDy5= ep_vkmYVlLQmJujLC4$ for graphic product...

ATTN...WFO...DVN...ARX...DMX...FSD...OAX...

LAT...LON 40829616 41109669 41539692 42079675 42439631 42739541
43059318 43079208 42849135 42369096 41799105 41349153
41089232 40909421 40829616=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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