Valid 221200Z – 231200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS…OZARKS…MID MISSISSIPPI VALLEY AND SOUTHERN
GREAT LAKES…
…SUMMARY…
Scattered storms capable of marginally severe wind gusts and hail
will be possible from the southern Plains northeastward into the
southern Great Lakes region this afternoon.
…Southern Plains/Ozarks/Mid Mississippi Valley/Southern Great
Lakes…
A southwest mid-level flow pattern will be in place today from the
Great Plains into the Great Lakes as an upper-level trough moves
across the High Plains. A cold front will advance southeastward into
the southern Plains, Ozarks and mid Missississippi Valley. Ahead of
the front, surface dewpoints in the mid to upper 60s F will
contribute to some destabilization. This combined with large-scale
ascent associated with the High Plains upper-level trough will
result in scattered convective initiation along the moist corridor
by afternoon. A low-level jet oriented southwest-to-northeast ahead
of the front will also provide support for convective development.
In addition to the moist airmass, moderate deep-layer shear is
forecast to be in place along the front. The shear along with
steepening low-level lapse rates will support a marginal wind damage
threat during the mid to late afternoon. Hail will also accompany
the stronger updrafts. At this point, instability is forecast to be
the greatest in the southern Plains where the chance of a marginal
severe threat appears to be slightly greater than in areas further
to the northeast.
..Broyles/Elliott.. 09/22/2019
$$