ZCZC SPCSWOMCD ALL
ACUS11 KWNS 312356
SPC MCD 312356
MNZ000-IAZ000-SDZ000-010200-
Mesoscale Discussion 1776
NWS Storm Prediction Center Norman OK
0656 PM CDT Wed Jul 31 2024
Areas affected...Southeast South Dakota...Far Southwest Minnesota
Concerning...Severe potential...Watch possible
Valid 312356Z - 010200Z
Probability of Watch Issuance...60 percent
SUMMARY...A severe threat may develop over part of southeastern
South Dakota over the next couple of hours. The severe threat may
also impact far southwest Minnesota later this evening. Large hail,
damaging wind gusts and an isolated tornado threat will be possible
with the stronger storms.
DISCUSSION...Over the last hour, mosaic radar imagery shows the
development of isolated strong storms about 50 to 60 statute miles
to the southwest of Sioux Falls. The storms are located to the
southwest of a pocket of extreme instability, where the RAP is
analyzing MLCAPE in the 4000 to 5500 J/kg range. In addition to the
instability, the storms are being supported by large-scale ascent
associated with a northern Plains shortwave trough, evident on water
vapor imagery. Short-term model forecasts including the HRRR,
suggest that the storms will grow upscale into a larger convective
cluster, moving into southwestern Minnesota later this evening. The
instability, combined with moderate deep-layer shear and steep
mid-level lapse rates (shown by the RAP), suggest that supercell
formation will be possible. Supercells will likely be associated
with large hail and isolated severe wind gusts. Hailstones greater
than 2 inches in diameter will be possible. A transition to a more
linear structure will be possible as low-level flow increases,
especially if a cold pool can organize.
..Broyles/Smith.. 07/31/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FSD...ABR...
LAT...LON 43269577 43009676 42999757 43019841 43049881 43109909
43209921 43269929 43469936 43649931 43879910 44189864
44429798 44709677 44549553 43759509 43269577
NNNN