South Dakota Mesoscale Discussion

Areas affected…southeast ND…eastern SD and extreme southwest MN

Concerning…Severe potential…Severe Thunderstorm Watch likely

Valid 151818Z – 151945Z

Probability of Watch Issuance…80 percent

SUMMARY…Large hail and damaging wind gusts will be possible this
afternoon and evening across parts of southeast North Dakota into
eastern South Dakota and perhaps southwest Minnesota.

DISCUSSION…Modest heating to the east of a surface cold
front/trough across southeast ND into eastern SD will continue this
afternoon. Weak to moderate instability is currently present across
the region, aided by low 60s surface dewpoints beneath midlevel
lapse rates around 6.5-7.5 C/km. A shortwave impulse will continue
eastward across the Dakotas this afternoon, providing greater
forcing for ascent and helping to erode remaining MLCINH. This
should result in increasing convective coverage and intensity along
the surface boundary over the next few hours. High-based cells may
initially develop, supported by 40 kt effective shear. An attendant
threat of large hail and damaging downburst winds is possible with
these initial storms. As linear ascent increases, upscale growth
into one or more bowing segments is expected, increasing damaging
wind potential into this evening with eastward extent. A severe
thunderstorm watch will likely be needed for portions of the region
by 20z.

..Leitman/Grams.. 08/15/2019

…Please see for graphic product…


LAT…LON 46559740 45429632 44549613 43759621 43119715 43019815
43029881 43240007 43990083 44570074 45659996 46399930
46539894 46669824 46559740

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