698
ACUS11 KWNS 190430
SWOMCD
SPC MCD 190430
MNZ000-IAZ000-NEZ000-SDZ000-190600-

Mesoscale Discussion 1716
NWS Storm Prediction Center Norman OK
1130 PM CDT Fri Jul 18 2025

Areas affected...North-central/northeast NE...southeast
SD...southern MN...northwest/north-central IA

Concerning...Severe Thunderstorm Watch 524...

Valid 190430Z - 190600Z

The severe weather threat for Severe Thunderstorm Watch 524
continues.

SUMMARY...Some severe threat may continue into the overnight hours.

DISCUSSION...Two clusters of storms are ongoing in and near WW 524
late this evening. A small southward-moving supercell cluster across
north-central NE has weakened somewhat compared to earlier this
evening, but still resides within a favorable environment for
organized convection, with MLCAPE greater than 2500 J/kg and
moderate deep-layer shear in place. Increasing MLCINH is decreasing
the window of opportunity for surface-based storms, but there
remains some potential for large hail, localized severe gusts, and
possibly a tornado for as long as these supercell structures
persist. The easternmost cell in this cluster has shown some
tendency for southeastward propagation, which could eventually
spread some severe threat into parts of eastern NE.

Buoyancy is somewhat weaker into southwest MN, but otherwise the
environment is similarly favorable for organized convection. A
localized threat for all severe hazards will remain possible in the
short term. A modest nocturnal low-level jet may support some
upscale growth in this area with time, which would tend to move
southeastward across IA overnight, potentially accompanied by a
threat for locally damaging wind and isolated hail. Eventual
downstream watch issuance is possible if short-term trends support
organized upscale growth.

Between these two ongoing clusters, some increase in storm coverage
remains possible within the conditionally favorable environment
across southeast SD late tonight, in conjunction with the nocturnal
low-level jet. At least an isolated severe threat could accompany
any robust development in this area into the early overnight hours.

..Dean/Hart.. 07/19/2025

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

ATTN...WFO...ARX...MPX...DMX...FSD...OAX...GID...LBF...UNR...

LAT...LON   41630142 42320147 43439905 43999783 44659591 44469390
            44079262 43279332 41779583 41249843 41320139 41630142

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN