ZCZC SPCSWOMCD ALL
ACUS11 KWNS 132010 
SPC MCD 132010 
MNZ000-SDZ000-NDZ000-132115-

Mesoscale Discussion 1854
NWS Storm Prediction Center Norman OK
0310 PM CDT Wed Oct 13 2021

Areas affected...Portions of North and South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 132010Z - 132115Z

Probability of Watch Issuance...5 percent

SUMMARY...A low-end risk for a tornado will be be possible this
afternoon. Given the nature of the threat a watch is unlikely.

DISCUSSION...As of 1955 UTC, regional WV imagery showed a deep
vertically stacked low was located across western SD. To the north
and east of the low, satellite imagery showed clearing taking place
across the ND/SD border. Diurnal heating is supporting weak
destabilization within the narrow zone ahead of the surface
cold/occluded front. Towering cumulus should evolve into an arc of
low topped thunderstorms this afternoon. Model soundings show steep
low-level lapse rate with 0-3 km MLCAPE in excess of 100 J/kg. With
abundant vertical vorticity close to the low center, a few weakly
rotating storms may have the potential to produce a brief weak
tornado. Given the small spatial and temporal severe risk, a watch
is unlikely.

..Lyons/Mosier.. 10/13/2021

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

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   45229675 45319717 45599762 45599817 45519860 45329903
            45289924 45339949 45599968 45969974 46209968 46589913
            46679836 46559756 45889679 45749677 45379672 45229675 

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