Valid 101200Z – 111200Z
…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN PLAINS TO THE OZARKS…
…SUMMARY…
Severe thunderstorms are possible this afternoon and evening across
portions of north Texas, central and eastern Oklahoma, northwest
Arkansas, southwest Missouri and far southeast Kansas. Large hail,
damaging wind gusts and a couple of tornadoes are all possible.
…Southern Plains Vicinity to central MO…
A mid/upper low over WY this morning will pivot eastward across the
northern Plains, while the associated trough shifts eastward across
the southern Rockies toward the southern/central Plains by Friday
morning. A surface low over KS will develop east/northeast toward
the upper MS Valley by tonight. A cold front attendant to the low
will sweep east/southeast across the central/southern Plains and
lower MO Valley by 00z, and from northeast MN to the mid-MS Valley
and central TX by Friday morning.
Thunderstorms are expected to be ongoing across parts of southern IA
into northern MO this morning in strong warm advection regime ahead
of the surface low and front. Steep midlevel lapse rates and strong
deep layer shear will promote the potential for mainly small hail
from elevated convection. As the surface low and cold front approach
late morning/early afternoon, some additional convection could
develop near the triple point, but convective debris/cloud cover is
expected to limit destabilization across much of the lower MO
Valley.
Further south, stronger heating from west-central/southwest MO into
eastern OK/far north TX is expected. Aided by widespread dewpoints
in the mid to upper 60s, MLCAPE approaching 2000 J/kg is forecast
ahead of the front, and thunderstorms are expected to develop from
far western MO/southeast KS into central OK and north TX by 21z.
Shear profiles will support semi-discrete cells initially, but an
increasing south/southwesterly LLJ generally parallel to the cold
front will lead to outflow interactions and upscale growing into
clusters/line segments. Nevertheless, backed low level winds will
support tornado potential in semi-discrete initial convection as
well as through mesovortex processes in line segments. Additionally,
steepening midlevel lapse rates will support a large hail threat,
especially where storm mode maintains semi-discrete characteristics.
Damaging winds also will be a concern throughout the afternoon and
evening, especially if forward-propagating/bowing line segments
develop as the cold front surges east/southeast across the Ozark
Plateau.
..Leitman/Nauslar.. 10/10/2019
$$