ACUS11 KWNS 172234
SWOMCD
SPC MCD 172233=20
IAZ000-NEZ000-180000-

Mesoscale Discussion 0460
NWS Storm Prediction Center Norman OK
0533 PM CDT Thu Apr 17 2025

Areas affected...eastern Nebraska

Concerning...Tornado Watch 141...

Valid 172233Z - 180000Z

The severe weather threat for Tornado Watch 141 continues.

SUMMARY...The greatest large to very large (2 to 3.5 inch) hail and
severe wind threat will exist ahead of a supercell in east-central
Nebraska this evening, potentially impacting the Omaha metro area. A
tornado threat will also increase near sunset.

DISCUSSION...A supercell has developed slightly north of the cold
front in Hamilton County, Nebraska. An additional storm has
developed to its northeast along this frontal zone. One or 2
dominant supercells are expected to emerge out of this as they move
east this evening. Some slowing of the surface front, augmentation
of the boundary by the developing supercell, and eastward
acceleration of the storms should allow them to move along or
possibly even ahead of the front by later this evening. The
environment ahead of this activity is very favorable for supercell
maintenance and the potential for large to very large hail.
Modifying the OAX 20Z RAOB for the environment slightly ahead of
this storms (87/59F) shows an uncapped parcel with nearly 3000 J/kg
MLCAPE, ample buoyancy through the hail growth zone, and 50-60 knots
of effective shear. This, combined with expectation for a discrete
storm mode, will support very large hail (baseball to softball size)
with the strongest supercells.

The 21Z WoFs highlights the corridor of the greatest threat ahead of
the ongoing supercell into western Iowa by later this evening with
WoFS hailcast also indicating peak hail size around 2.75" this
evening. In addition, WoFs shows a peak STP around 2 to 3 around 00Z
near the Missouri River which will correspond well with peak
intensity and location of the ongoing supercell. Therefore, there
will be a favorable time window around 00Z to 01Z as the low-level
jet strengthens when the tornado threat will be maximized.

..Bentley.. 04/17/2025

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8R1p0r9Ez-8YakjEzGlDBC53YQBSO_WEOGM6ODXZnahBwAEcvnYh554EM8Q8lK3HeyiCRpI_i= ZFaxCIS9yLCrtdDtm0$ for graphic product...

ATTN...WFO...OAX...GID...

LAT...LON 40729789 40809808 40989816 41139813 41579740 41739635
41669555 41409529 41089531 40909635 40799755 40729789=20

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


=3D =3D =3D
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