South Dakota Mesoscale Discussion

Areas affected…southwestern North Dakota

Concerning…Severe potential…Watch unlikely

Valid 112219Z – 120015Z

Probability of Watch Issuance…20 percent

SUMMARY…Damaging wind gusts or an isolated tornado cannot be
completely ruled out with convection across the discussion area. A
WW issuance is not anticipated, though convective trends continue to
be monitored.

DISCUSSION…A cluster of strong to isolated severe storms continues
across southwestern North Dakota currently. These storms are in a
moderately unstable environment (1000-2000 J/kg MUCAPE) with
sufficient deep shear (35-40 kts) for updraft organization, and even
though low-level wind fields are relatively weak, easterly surface
winds veering to westerly with height are supporting weak updraft
rotation in the strongest cores. This is apparent with recently
severe-warned convection over Adams County, and with time other
storms may occasionally rotate given the shear profiles. Modest
increases in low-level flow after about 00-01Z or so will also
enhance shear profiles and further support rotation, though storms
will also encounter gradually stabilizing boundary layer
thermodynamic profiles in tandem with the strengthening shear. The
scenario may only support an isolated severe threat in a localized,
temporally brief nature that will not necessitate any WW issuance,
although convective trends will be monitored for any increase in the
threat beyond current expectations.

..Cook/Hart.. 08/11/2019

…Please see for graphic product…


LAT…LON 46890386 47010273 47050127 46730037 46259999 45940011
45780157 45910323 45970390 46200419 46660423 46890386

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