ACUS01 KWNS 181624
SPC AC 181622
Day 1 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
1022 AM CST Sat Nov 18 2017
Valid 181630Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
OHIO AND TENNESSEE VALLEYS...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE OHIO AND TENNESSEE VALLEYS...
Thunderstorms capable of severe wind gusts, marginal hail, or a
brief tornado will be possible this afternoon across parts of the
Ohio and Tennessee Valley regions.
...OH/TN Valley Region...
Water vapor imagery shows a vigorous upper trough moving rapidly
eastward across the Central Plains. Large scale forcing ahead of
this feature is overspreading the mid MS and lower OH valleys, and
should result in scattered afternoon thunderstorms. Storms will be
focused along a cold front - initially over central/southern IL and
southeast MO. This activity will spread eastward through the
evening hours into parts of IN/KY/TN. Wind fields are very strong,
and are supportive of organized storms with bowing and supercell
structures. However, low-level moisture and CAPE are quite limited
today with dewpoints only in the 50s to lower 60s, and MUCAPE values
below 1000 J/kg. Considerable cloud cover and slightly veered
low-level winds are also negatives for a more robust severe event.
Nevertheless, the initial storms over IL/MO and western KY/TN may
produce large hail, with the risk of damaging winds increasing
through the event farther east. A tornado or two is also possible
in early supercells, and along the QLCS later today.