739
ACUS02 KWNS 241745
SWODY2
SPC AC 241743

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1243 PM CDT Fri May 24 2024

Valid 251200Z - 261200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF
KANSAS...OKLAHOMA...AND INTO FAR WESTERN MISSOURI...

...SUMMARY...
Several strong to violent tornadoes, extreme hail, and corridors of
widespread wind damage are forecast over parts of the central and
southern Plains from late Saturday afternoon into the night.

...Synopsis...
A fast-moving shortwave trough will move from the Four Corners
states into the central Plains on Saturday, with a deepening surface
low into western KS by 00Z. A warm front will extend from northwest
TX into AR Saturday morning, and will rapidly return north across
OK, southern KS, and southwest MO through 00Z.

South of the warm front, a very moist and unstable air mass will
develop, with mid 70s F dewpoints from TX into OK. The deeper
southerly flow through 850 mb will rapidly increase late in the day,
accelerating theta-e advection into the central Plains. A dryline
will remain in place for much of the period from southwest KS into
western OK/northwest TX.

The end result will be a rare combination of instability and shear
across the Moderate Risk area, with potential for particularly
strong tornadoes, wind, and extreme hail.

...Central and Southern Plains...
Much of the day will be void of storms as the warm sector develops.
Rapid changes in the environment are expected during the late
afternoon and evening, as the approaching upper wave interacts with
the uncapped air mass. Storms are likely to form first across
western NE into western KS near the developing cold front and
surface low, an beneath the strongest cooling aloft. Strengthening
southwest flow behind the dryline and deep mixed layers should
easily support development after 21Z in this area. Very large hail
is likely initially, with increasing tornado threat with long-lived
supercells as they evolve eastward through the evening. Long-tracked
and violent tornadoes will be possible as the low-level jet
increases during the evening, while maintaining a very moist and
unstable boundary layer. Extreme hail over 4.00 inches is expected
with such strong instability and impressive mid to upper level wind
speeds.

With time, storms are expected to merge into a severe MCS, possibly
with corridors of extreme wind damage, as it proceeds into eastern
KS and far western MO late.

Farther south along the dryline and within the open warm sector
across OK and into TX, overall large-scale lift will be less than
points north. However, at least isolated, very large supercells
capable of destructive tornadoes and extreme hail will be possible
with storms that form late in the day and evening and move across
western and central OK and pars of northern TX.

Aside from the steeper lapse rate environment near the dryline,
mesoscale conditions will need to be closely monitored for low-level
confluence lines within the deepening moist sector east of the
dryline. The cap will not be particularly strong or high off the
ground (low LFC). Given mid 70s F dewpoints and expected late
initiation, this may be a plausible scenario from northwest TX into
central OK. Only reduced confidence in total storm coverage is
precluding a High Risk at this time.

Farther south, cells should be more isolated along the dryline into
central TX, however, the environment will remain quite favorable for
late day significant hail, and perhaps a tornado.

..Jewell.. 05/24/2024

$$