686
ACUS11 KWNS 170348
SWOMCD
SPC MCD 170347
KSZ000-NEZ000-170545-

Mesoscale Discussion 1324
NWS Storm Prediction Center Norman OK
1047 PM CDT Mon Jun 16 2025

Areas affected...western/central Nebraska southward into
western/central Kansas

Concerning...Severe Thunderstorm Watch 424...

Valid 170347Z - 170545Z

The severe weather threat for Severe Thunderstorm Watch 424
continues.

SUMMARY...Thunderstorms continue to develop and expand in coverage
across the Central Plains this evening. Strong instability and shear
will continue to support a severe threat into the overnight hours.
An extension in space/time of existing Severe Thunderstorm Watch
#424, a new Severe Thunderstorm Watch, or both will likely be
needed.

DISCUSSION...A complex thunderstorm evolution is underway across
much of central and southern Nebraska this evening. There have been
numerous reports of measured severe-magnitude winds -- some greater
than 75 mph -- across portions of Severe Thunderstorm Watch #424,
despite the coherent upscale growth into a linear MCS. Interrogation
of local observations and radar data indicates that some, but not
all, of these have been associated with heat bursts.

Repeated initiation across Hayes County has yielded a northward
expanding arc of additional thunderstorms, perhaps associated with
thunderstorm outflows. The result has been the development of
numerous thunderstorms across the region, without a coherent,
large-scale direction of movement. Despite the number of storms,
instability remains quite high across western, central, and southern
Nebraska, with most-unstable CAPE values still in excess of 3500
J/kg across much of the area. Couple this with deep-layer shear
values remain in excess of 40 knots an increasing low-level jet,
severe thunderstorms should continue across portions of Severe
Thunderstorm Watch #424 past the 05 UTC expiration.

Expectations continue to be that with time the modified surface
front/congealed cold pools should begin to move southward taking
with it the bulk of the severe threat. Recent radar trends suggest
this may be occurring as new thunderstorm updrafts are developing
across Thomas, Sheridan, and Graham Counties in northwest Kansas.

With the anticipated southward development in Kansas and the
repeated initiation across portions of western/central Nebraska some
combination of a new Severe Thunderstorm Watch and local extensions
in space/time of existing Severe Thunderstorm Watch #424 will be
needed across the Central Plains this evening. Coordination of these
details will be finalized in the next hour.

..Marsh.. 06/17/2025

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...OAX...TOP...ICT...GID...LBF...DDC...GLD...

LAT...LON   41710167 41469753 38149582 38210163 41710167

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN