MD 0954 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR WESTERN SOUTH DAKOTA AND OTHER PORTIONS OF THE NORTHERN HIGH PLAINS
Mesoscale Discussion 0954
NWS Storm Prediction Center Norman OK
0205 PM CDT Sun Jun 21 2020
Areas affected...western South Dakota and other portions of the
northern High Plains
Concerning...Severe potential...Watch unlikely
Valid 211905Z - 212130Z
Probability of Watch Issuance...20 percent
SUMMARY...Scattered thunderstorms are expected to develop across
western South Dakota and surrounding areas this afternoon. As these
storms move southeast, damaging winds and large hail are possible.
Given the likely marginal and isolated nature of the severe threat,
a watch issuance is unlikely.
DISCUSSION...West-northwest upper-level flow is overspread the
northern Rockies and Plains with multiple low-amplitude shortwave
troughs embedded within it per water vapor imagery. Sporadic
lightning has been observed across portions of eastern Idaho and
northern Wyoming this morning into early afternoon with a few
observed lightning flashes in western South Dakota during the last
hour with struggling convection. Given the moisture and forcing for
ascent aloft, cloud cover has mitigated insolation across much of
the northern high Plains/vicinity. This along with diffuse surface
convergence have delayed and limited convective initiation. However,
deeper cumulus clouds and higher cloud tops have been observed
recently indicating potential destabilization.
As surface temperatures warm into the 70s to low 80s F storm
coverage will likely increase. Storms are expected to develop during
the afternoon and into the evening and move generally to the
southeast across the area. The overall storm environment represents
a marginally severe threat for large hail and damaging winds with
coverage of severe storms likely relatively limited.
..Nauslar/Guyer.. 06/21/2020
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...BIS...LBF...UNR...CYS...BYZ...
LAT...LON 42150121 42760445 44790559 45470535 46490424 46320300
45510075 44910012 43970021 42150121
from SPC Mesoscale Discussions https://bit.ly/37NgIv7
Be First to Comment