Valid 310100Z – 311200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE HIGH PLAINS AND MID MISSISSIPPI VALLEY…
…SUMMARY…
Marginally severe thunderstorms with hail and strong wind gusts will
be possible this evening across parts of the High Plains. A few
storms with strong wind gusts will also be possible in the mid
Mississippi Valley.
…High Plains…
The latest water vapor imagery shows a west to northwest mid-level
flow pattern over the central U.S. with a subtle shortwave trough
moving through the central High Plains. Thunderstorms have developed
just ahead of the trough along a corridor of moderate instability
from the western Texas Panhandle into eastern Colorado and western
Nebraska. MLCAPE values across this area estimated by the RAP to be
in the 1000 to 2000 J/kg range. This combined with 0-6 km shear of
40 to 50 kt, evident on regional WSR-88D VWPs and steep low to
mid-level lapse rates should be enough for a marginal severe threat
this evening. The stronger storms could produce hail and isolated
wind gusts approaching severe limits.
…Mid Mississippi Valley…
The latest water vapor imagery shows an upper-level trough over the
Ozarks. Ahead of the trough, a cold front is located from southern
Missouri into southern Illinois. Thunderstorms have developed along
the front on the northwestern edge of a moist airmass with surface
dewpoints from the mid 60s to lower 70s F. This is contributing to a
corridor of moderate instability across southern Illinois into
southern Indiana. As the MCV associated with the convective complex
moves eastward, a marginal severe threat will likely continue along
this corridor of instability. A few strong wind gusts are expected
to be the primary hazard.
..Broyles.. 08/31/2019
$$