- Day Three
acus03 kwns 200730
Storm Prediction Center ac 200729
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0229 am CDT Tue Aug 20 2019
Valid 221200z - 231200z
..there is a marginal risk of severe thunderstorms from southern
Kansas and Missouri into northern Oklahoma and Arkansas...and over
the northern High Plains...
At least isolated severe storms are possible Thursday from parts of
Kansas and Oklahoma eastward across Missouri and Arkansas, and from
eastern Montana into the western Dakotas.
Strong west/southwest winds aloft will remain over the northeast as
an upper low moves slowly east across Quebec, and a cold front moves
rapidly east across New England providing drying. To the west, a
progressive shortwave trough will move across Montana and ND, providing
cooling aloft and lift.
At the surface, a westward continuation of the New England cold
front will remain quasi-stationary from the Ohio Valley into the
central/Southern Plains, with ample moisture and instability for
..southern Kansas and MO into northern OK and Arkansas...
Areas of storms are likely to be ongoing Thursday morning along the
primary east-west front, most likely across KS, MO, and Illinois. Heating
will occur south of this activity and attendant outflow boundaries,
mainly over OK and AR, removing convective inhibition. Weakly
veering low-level winds with height beneath 20 kt mean midlevel
westerlies will favor southeastward-moving clusters of storms, with
a marginal wind threat.
..northern High Plains...
A cold front will move into eastern Montana and Wyoming Thursday afternoon,
providing convergence as southeast winds ahead of it maintain mid to
upper 50s f dewpoints. Steep lapse rates through a deep layer as
well as modest 30 kt deep-layer shear will likely favor mixed storm
Mode with at least isolated severe hail or wind. Storms will likely
weaken and/or become elevated overnight as they continue into the
western Dakotas where capping will exist.