South Dakota Mesoscale Discussion

Areas affected…Southwest ND…Western SD…Northeast WY

Concerning…Severe potential…Watch unlikely

Valid 032321Z – 040115Z

Probability of Watch Issuance…20 percent

SUMMARY…Isolated supercells capable of large hail and localized
severe wind gusts will remain possible into mid evening before
weakening. Watch issuance is unlikely due to limited coverage and
duration of the threat.

DISCUSSION…Widely scattered strong thunderstorms are ongoing
across portions of the northern High Plains at 2315Z, with the
strongest storm across southwest ND displaying supercell
characteristics. Moderate instability (MLCAPE of 1500-2000 J/kg) and
sufficient effective shear (40-50 kt) will support the potential for
supercell structures with ongoing convection in the short term,
though storms are expected to remain widely scattered given limited
large-scale ascent across the region. Large hail and locally severe
wind gusts will be the primary threats.

Increasing MLCINH with eastward extent will limit the potential for
supercells to spread very far downstream, though cells that develop
more rightward motion (like the cell in southwest ND) will have a
longer residence time within a weakly capped environment and have
greater potential to persist for another 1-2 hours across western
SD. An eventual weakening trend for any remaining cells is expected
later this evening in conjunction with diurnal
cooling/stabilization. Due to the limited coverage and duration of
the severe threat, watch issuance is unlikely.

..Dean/Thompson.. 08/03/2019

…Please see for graphic product…


LAT…LON 44070515 44950384 45910374 46750342 46700267 46150234
45180250 44360284 43860300 43610430 44070515

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