U.S. Severe Weather Forecast for Tomorrow
Upcoming severe weather outlook.
acus02 kwns 231727
Storm Prediction Center ac 231726
Day 2 convective outlook
National Weather Service Storm Prediction Center Norman OK
1226 PM CDT Wednesday Apr 23 2014
Valid 241200z - 251200z
..there is a slight risk of severe thunderstorms across southeast MO...Much of
Arkansas and into western Tennessee...and into northwestern MS and northern la...
Scattered strong to severe storms are expected to form along a
corridor from northern Louisiana into southeast Missouri...and then
spread east toward western Tennessee and northwest Mississippi into
the evening Thursday. Locally damaging winds and hail will be the
primary threats with this activity.
A strong middle- and upper-level trough -- comprised of phased pieces
of northern- and southern-stream energy -- will cross the central U.S. This
period. The southern feature within this trough in particular will be a
focus with respect to the convective/severe forecast for the day 2
period...as it shifts out of the plains and crosses the lower MO/middle
MS valley region through the afternoon and evening hours.
At the surface...low pressure is forecast to shift eastward across the
Iowa/MO region through the afternoon...and then the Midwest states
during the evening and overnight. As this occurs...a trailing cold
front will move eastward across the lower MO/middle MS valleys and southeastward
across Arkansas/TX/la through sunset. This boundary will focus a zone of
showers and thunderstorms -- with intensity/severe risk peaking
diurnally across Arkansas and vicinity.
..sern MO/western Tennessee southwestward into northern la...
A moistening airmass is prognosticated ahead of the advancing cold
front...as southerly boundary-layer winds advect low 60s dewpoints across
Arkansas and into southeastern MO. However...diurnal heating is forecast to be
hindered by ongoing precipitation and associated cloud cover...which
should be spreading eastward toward/into the slight risk area early in
the period. As a result...only marginal destabilization is forecast
-- particularly into central and northern Arkansas and adjacent southeastern MO where
strongest flow aloft /on the southern fringe of the upper vorticity maximum/ is
prognosticated to exist.
That being said...the strength of the system and associated
strong/compact jet streak is suggestive of severe risk despite the
anticipated marginal thermodynamic environment. Though shear would
support rotating storms...it appears that a linear Mode will be
favored and thus damaging winds should be the primary severe risk.
A tornado or two...however...cannot be ruled out -- either within
the broader convective line or with any isolated storm ahead of the
line. Severe-sized hail would appear to be most likely across the
southern half of the outlook...where somewhat greater destabilization
potential is evident.
Given the marginal thermodynamics anticipated...storms should show a
fairly strong diurnal peak in intensity...with weakening convection
and thus diminishing severe risk likely by evening as the front
moves east of the MS valley.