- Day Three
acus02 kwns 230623
Storm Prediction Center ac 230623
Day 2 convective outlook corr 1
National Weather Service Storm Prediction Center Norman OK
0123 am CDT Sat may 23 2015
Valid 241200z - 251200z
..there is a slight risk of severe thunderstorms across central and south
..there is a marginal risk of severe thunderstorms from the lower MS valley to the
Corrected probability graphic.
Scattered to numerous thunderstorms are expected across much of the
southern and Central Plains Sunday. The strongest convection will
likely develop across central and south Texas where large
hail...damaging winds...and perhaps a few tornadoes can be expected.
Elsewhere...isolated hail and wind may accompany strong convection
from portions of the lower Mississippi Valley into the Central
Broad but weak 12hr height falls will spread into the southern/Central
Plains Sunday ahead of low-latitude short-wave trough. Latest model
guidance is fairly consistent ejecting a short-wave trough into the
main body of Texas by 24/18z...then northeastward into the middle MS valley during
the overnight hours. Extremely high precipitable water values...ranging from 1.75-2
inches...will surge northward ahead of this feature from the western Gulf
basin...northward into eastern Kansas. Numerous showers/thunderstorms will develop ahead
of the short wave within modestly sheared but weak lapse rate
environment. Much of the convection will produce very heavy
rainfall and extensive clouds will limit boundary layer heating.
One exception will be near the dry line...but within Post short wave
regime. Latest forecast soundings suggest the greatest
shear/instability combination will be across central/southern Texas prior to
large scale forcing ejecting north into the middle MS valley. Greatest
severe risk will be across this region for thunderstorm activity that
evolves along southern fringe of stronger flow aloft within base of
ejecting trough. Isolated supercells could produce large
hail...damaging winds and perhaps a few tornadoes. It/S not clear
if organized deep convection will develop along the dry line during
the late afternoon hours and for this reason 5 percent severe probs
will be maintained.
Farther north across Nebraska...thunderstorms should develop within
southeasterly low-level flow beneath seasonally weak middle-level southerly 500mb
flow. A few slow-moving supercells could evolve across this region
that would pose a risk of large hail.