MD 2183 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR EASTERN SD INTO SOUTHWEST MN AND EXTREME NORTHWEST IA
Mesoscale Discussion 2183
NWS Storm Prediction Center Norman OK
0210 PM CDT Sat Sep 23 2023
Areas affected…Eastern SD into southwest MN and extreme northwest
IA
Concerning…Severe potential…Watch possible
Valid 231910Z – 232145Z
Probability of Watch Issuance…60 percent
SUMMARY…Storm evolution remains uncertain this afternoon, but
there is some threat for eventual supercell development, with an
attendant risk of hail and a couple tornadoes. Eventual watch
issuance is possible for portions of the region.
DISCUSSION…A surface low is deepening this afternoon near the
southeast SD/northeast NE border, in advance of a mid/upper-level
low moving across west-central SD. A leading shortwave trough has
recently ejected northeastward in advance of this mid/upper-level
low, and is helping to sustain storm clusters across northeast SD
and northwest/north-central IA. Midlevel drying in the immediate
wake of this shortwave has resulted in some clearing across eastern
SD into southwest MN, and additional modest heating/destabilization
will be possible through the afternoon.
As the primary mid/upper-level low approaches later this afternoon,
renewed thunderstorm development will be possible from eastern SD
into southwest MN, though outflow from the Iowa storm cluster may
constrain the eastward extent of favorable destabilization to some
extent. Deep-layer shear will remain favorable for organized
convection, and most guidance suggests a notable strengthening of
the low-level jet with time, especially across southwest into
south-central MN. Depending on the magnitude of destabilization
across the region, a few supercells may evolve with time later this
afternoon, with a threat of a couple tornadoes and at least isolated
hail. Eventual watch issuance is possible in order to address these
threats.
..Dean/Guyer.. 09/23/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…MPX…FSD…ABR…
LAT…LON 42849696 43359762 44599749 45039720 45399665 45569633
45569493 45199405 44539398 43949424 43729453 43509502
42979593 42889640 42849696
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