Valid 120100Z – 121200Z
…THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL HIGH PLAINS…
…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS INTO PORTIONS OF SOUTHERN LOWER MI…
…SUMMARY…
Severe thunderstorms will continue tonight across the central Plains
while isolated strong-severe storms will linger from southern
Wisconsin to the upper Ohio Valley.
…01z Update…
Large-scale height falls are spreading across the central/northern
Plains ahead of a strong short-wave trough progressing across
WY/UT/CO. Substantial thunderstorm activity has evolved ahead of
this feature, primarily along a corridor from northeast CO into
central NE, along/north of a synoptic front draped across this
region. As large-scale forcing spreads east tonight, upward-evolving
convection is expected across NE as LLJ increases in response to
approaching short wave. Currently, several supercell structures are
noted across northeast CO into central NE, but storm mergers and
forcing should contribute to an expanding complex of storms over the
next few hours. Until an MCS emerges, some tornado threat, along
with large hail, can be expected with supercell structures. Damaging
winds may become more common if bowing structures ultimately develop
along leading edge of an intensifying cold pool. Robust convection
is expected to spread/develop downstream over the next few hours,
possibly reaching southwestern MN as an elevated severe threat.
Downstream across the Great Lakes/OH Valley, trailing influence of
ejecting short-wave trough lingers across southern lower MI where a
loosely organized MCS has evolved. This activity is beginning to
turn more southeast and should approach western Lake Erie over the
next few hours. Latest hail algorithm suggests the strongest
updrafts are producing hail generally less than 1″ and primary
severe threat the remainder of this evening will be locally damaging
winds.
..Darrow.. 09/12/2019
$$