South Dakota Mesoscale Discussion

Areas affected…southeast Montana…northeast Wyoming and western
South Dakota

Concerning…Severe potential…Watch unlikely

Valid 150214Z – 150345Z

Probability of Watch Issuance…20 percent

SUMMARY…Isolated storms may continue developing southeast through
northeast Wyoming and western South Dakota this evening, posing a
risk for isolated large hail and downburst winds. At this time it
appears storm coverage will probably remain too sparse for a WW, but
trends will continue to be monitored.

DISCUSSION…As of mid evening a few storms persist over southeast
MT, with the strongest storm having supercell characteristics
approaching the northeast WY border. The downstream atmosphere is
moderately unstable with 1500-2000 J/kg MUCAPE. A modest increase in
convective inhibition is occurring with respect to surface-based
parcels with onset of nocturnal cooling. However, a few storms may
persist with slightly elevated updrafts having inflow rooted just
above the surface. Thus isolated storms could persist into a portion
of western SD and extreme northeast WY and pose a threat for large
hail and downburst winds this evening. Stronger forcing accompanying
a shortwave trough moving through eastern MT should remain north of
this region. This along with the absence of a substantial low-level
jet suggest storm coverage will probably remain very isolated.

..Dial/Goss.. 08/15/2019

…Please see for graphic product…


LAT…LON 43360396 44120500 44760594 45560411 44640295 43530271

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