MD 1856 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF EASTERN WYOMING INTO SOUTHEAST MONTANA AND FAR WESTERN SOUTH DAKOTA
Mesoscale Discussion 1856
NWS Storm Prediction Center Norman OK
0434 PM CDT Sun Oct 02 2022
Areas affected...portions of eastern Wyoming into southeast Montana
and far western South Dakota
Concerning...Severe potential...Watch unlikely
Valid 022134Z - 022330Z
Probability of Watch Issuance...20 percent
SUMMARY...A few instances of severe wind or hail may accompany the
stronger storms into early evening. The severe threat is expected to
remain isolated and a WW issuance is not currently anticipated.
DISCUSSION...Thunderstorms have gradually been increasing in
coverage and intensity over the past few hours across the northern
High Plains in advance of a weak surface cold front. Ahead of the
storms, low to mid 50s surface dewpoints are overspread by 8-9 C/km
low-level lapse rates and 7 C/km mid-level lapse rates, contributing
up to 1000 J/kg MLCAPE (per 21Z mesoanalysis). 40+ kts of
southwesterly 500 mb flow are overspreading weak south-southwesterly
surface winds over the central Rockies, contributing to 35 kts of
effective bulk shear. RAP forecast soundings depict elongated
hodographs, suggesting most of the effective bulk shear is
speed-driven. As such, any storms that manage to mature and become
sustained may become multicellular or short line segments, the
strongest of which may produce isolated severe gusts/hail. Given the
expected isolated nature of the severe threat, a WW issuance appears
unlikely.
..Squitieri/Grams.. 10/02/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BIS...UNR...CYS...BYZ...GGW...RIW...
LAT...LON 41950440 41680533 41810627 42140676 43310556 44330501
45340520 45940582 46520617 46950587 47110457 46970374
46420273 45240210 43640267 42620356 41950440
