226
ACUS01 KWNS 011241
SWODY1
SPC AC 011240

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 AM CDT Sat Jun 01 2024

Valid 011300Z - 021200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FROM WESTERN NE TO WEST TX...

...SUMMARY...
Scattered severe storms, including a few supercells, are expected to
develop across the central and southern High Plains region,
including portions of the Big Bend of Texas, this afternoon. This
activity should evolve into organized clusters while spreading into
the adjacent Great Plains later in the evening. Severe wind, hail,
and perhaps a couple of brief tornadoes are the expected risks.

...Central and southern High Plains through tonight...
Several clusters of thunderstorms are ongoing this morning across
western NE, near the KS/OK border, and along the NM/TX border.  Weak
low-level warm advection and/or remnant MCVs appear to be driving
this convection, though each of the clusters are likely to weaken
later this morning.  In the wake of this morning convection, a
surface front will persist across western NE, with weak lee
troughing farther to the south across eastern CO/NM in response to
modest westerly midlevel flow.  Scattered thunderstorms are expected
to form by mid afternoon along the surface boundaries and
immediately east of the higher terrain, and then move
eastward/southeastward onto the Plains through tonight.

The environment across southwest TX will favor splitting supercells
immediately east of the mountains, where long/straight hodographs
(with effective bulk shear 40-50 kt), steep midlevel lapse rates and
MLCAPE near 3000 J/kg will support very large hail of baseball size
(2.75 inches) or larger.  Isolated severe outflow gusts will also be
possible.  Farther north, a few supercells may also form across
eastern CO into western NE, where large hail up to 2-2.5 inches in
diameter will be possible.  Upscale growth into a storm cluster or
two is also expected later this evening into tonight from southwest
NE into western KS and the TX Panhandle, in response to a nocturnal
low-level jet and a related increase in low-level warm advection.
Large hail will be possible with the initial storms, but the threat
should evolve more to severe outflow winds of 60-75 mph with the
upscale growth.

...South central/southeast TX into southwest LA this afternoon...
Scattered thunderstorm development is expected today along a stalled
front extending from south central TX into southwest LA.  Regional
12z soundings revealed strong buoyancy along and south of the
boundary, with moderately strong westerly flow above the 500 mb
pressure level.  A mix of multicell clusters and, perhaps, some weak
supercell structures will be possible, with the potential to produce
isolated large hail and wind damage.  This area may need to be
monitored for a little higher wind/hail probabilities this
afternoon.

...MS/AL/TN area today...
A midlevel trough over the middle and lower MS Valley will move
slowly eastward to the TN/OH Valleys through tonight.  A couple of
different storm clusters will be possible today near and just east
of the midlevel trough where the surface warm sector across
MS/AL/TN.  Deep-layer vertical shear is relatively weak per regional
VWPs, but there is some low-level hodograph curvature within a warm
advection regime.  Given weak-moderate buoyancy where boundary-layer
dewpoints are in the upper 60s or greater, and later pockets of
surface heating in cloud breaks, a few storm clusters may include
embedded, weakly rotating storms capable of producing a brief
tornado or two, along with isolated wind damage.

..Thompson/Grams.. 06/01/2024

$$