SPC MD 1441


MD 1441 Image

Mesoscale Discussion 1441
NWS Storm Prediction Center Norman OK
1005 AM CDT Fri Jul 12 2019

Areas affected...portions of eastern SD and central/southern MN

Concerning...Severe potential...Watch unlikely 

Valid 121505Z - 121630Z

Probability of Watch Issuance...5 percent

SUMMARY...Strong storms may produce near-1 inch hail through midday.

DISCUSSION...Widely scattered thunderstorms have developed
along/just ahead of a surface front from central NE into eastern SD.
Additional development is possible along the boundary to the
northeast across central/southern MN as well where a deepening,
agitated CU field was noted in satellite imagery. This convective
development is likely being aided by a weak impulse/remnant MCV
ejecting eastward across SD per water vapor imagery, in addition to
warm advection atop an EML above 850mb noted in 12z regional RAOBs.
Despite being elevated, these storms are developing within a plume
of steep midlevel lapse rates of 7-8 C/km stretching across the
central Plains to the Upper Midwest and a moderately unstable
airmass with MUCAPE around 1500-2500 J/kg. Hi-res guidance is doing
a poor job in depicting this convection, with the 13z HRRR not
indicating any storms over the region until later this
afternoon/evening. While this does lead to some uncertainty in the
longevity of these strong morning storms, expect some
isolated/marginal hail threat for a few hours before convection
encounters drier air and less favorable shear with eastward extent.
While additional convection is still possible later this afternoon,
current storms are not expected to pose a widespread organized
severe threat in the short term, and a watch is not anticipated at
this time.

..Leitman/Grams.. 07/12/2019

...Please see www.spc.noaa.gov for graphic product...


LAT...LON   46499234 46689282 46649363 46249509 45669636 44939790
            43929916 43279903 42989841 42949719 43449595 44939374
            45749233 45999214 46329216 46499234 

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