South Dakota Mesoscale Discussion

Areas affected…Portions of the Northern High Plains

Concerning…Severe potential…Watch unlikely

Valid 032022Z – 032245Z

Probability of Watch Issuance…20 percent

SUMMARY…Initial thunderstorm development is underway over the
higher terrain and along/near the surface pressure trough across the
northern High Plains. Storms will be capable of producing severe
hail and gusty winds, but a watch is unlikely, owing to
limited/isolated coverage of severe thunderstorms.

DISCUSSION…Strong insolation across the region has resulted in
destabilization and reduction/removal of convective inhibition for
mixed-layer parcels. As a result, thunderstorms are developing over
the Laramie Mountains, Black Hills, and along the surface pressure
trough near the Montana-North Dakota border. Given mesoanalysis
estimates of 30-40 knots of effective-layer bulk shear (with
relatively straight hodographs) and 1000-1500 J/kg of MLCAPE,
multicellular and brief, splitting supercell modes will be possible.
As a result, the strongest updrafts will initially pose a severe
hail threat along with gusty winds, especially given the deep,
well-mixed boundary layers across the region, with the severe threat
ending shortly after sunset.

In the wake of a shortwave passage earlier today, upper-level
ascent/support is neutral/negligible for more widespread
thunderstorm development. As a result, severe thunderstorm coverage
across the region is expected to be too low to warrant a severe
thunderstorm watch, but convective trends will continue to be

..Jirak/Goss.. 08/03/2019

…Please see for graphic product…


LAT…LON 42400568 44130532 45800501 48680399 48780354 48760319
48730280 47810277 47020285 45040319 43680335 42750343
42230356 42220452 42220499 42400568

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