SPC MD 1727
[html]MD 1727 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF CENTRAL SOUTH DAKOTA
Mesoscale Discussion 1727
NWS Storm Prediction Center Norman OK
1152 PM CDT Fri Aug 26 2022
Areas affected...portions of central South Dakota
Concerning...Severe potential...Watch unlikely
Valid 270452Z - 270545Z
Probability of Watch Issuance...5 percent
SUMMARY...A marginally severe wind gust or two may acco*pany the
apex of a weakening bow-echo MCS. However, the presence of a stable
boundary layer should keep the severe gusts quite isolated, so a WW
issuance is not expected.
DISCUSSION...A well-defined but gradually weakening bow-echo
leading-line/trailing-precipitation MCS is underway across central
SD, which is traversing a surface-925 mb baroclinic zone and is
preceded by 20-35 kt LLJ (per 04Z mesoanalysis). On the warm side of
the baroclinic zone, temperatures are in the upper 60s/low 70s F
with near 70 F dewpoints, especially in eastern SD. RAP forecast
soundings suggest that the surface stable layer in this airmass
should allow for some of the stronger downbursts to reach the
surface, perhaps to 50 kts on a very isolated basis should some of
this air mix northward. As such, the severe wind threat is confined
to the apex of the bow echo over the next hour or so. Since the MCS
is confined roughly to the cool side of the boundary, the sparse
nature of the severe threat suggests that a WW issuance appears
unlikely.
..Squitieri/Grams.. 08/27/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...ABR...UNR...
LAT...LON 44610141 44769918 44839780 44569777 44249781 43939809
43739918 43730003 43780075 43850109 44610141
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Source: SPC MD 1727 (http://ht**://www.spc.noaa.gov/products/md/md1727.html)