000
ACUS02 KWNS 241732
SWODY2
SPC AC 241730

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Wed Apr 24 2024

Valid 251200Z - 261200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM WESTERN
KANSAS SOUTHWARD THROUGH THE EASTERN TEXAS PANHANDLE/WESTERN
OKLAHOMA INTO NORTHWEST TEXAS...

...SUMMARY...
Scattered severe thunderstorms are expected from late Thursday
afternoon into Thursday night across parts of the central and
southern Great Plains. Very large hail, severe wind gusts, and a
couple strong tornadoes will all be possible.

...Synopsis...
A shortwave trough is forecast to begin the day extended from
central NV into far northwest Mexico before then quickly moving
eastward across the Southwest and into the southern/central High
Plains, becoming increasingly negatively tilted with time. Strong
mid-level flow will accompany this shortwave, spreading
eastward/northeastward into the central and southern Plains ahead of
the parent shortwave.

At the surface, cyclogenesis is anticipated ahead of the shortwave
trough across the central High Plains, with the resulting low then
gradually moving northeastward from eastern CO into western
KS/southwest NE late Thursday night/early Friday morning. A
sharpening dryline will extend southward from this low throughout
most of the period. A warm front will extend east-southeastward
from this low as well, extending into northeast OK Thursday morning.
This warm front is forecast to move northward throughout the day,
moving through much of KS by early Friday morning. A moist and
buoyant warm sector will exist south of this front, and strong to
severe thunderstorms are anticipated the shortwave interacts with
it.

...Southern/Central Plains...
Numerous showers and thunderstorms will likely be ongoing Thursday
morning from north-central/eastern KS into western MO and
northeastern OK, supported by strong warm-air advection across the
warm front.  Given that at least moderately low-level southerly flow
is expected to persist throughout the period, expectation is that
this activity will persist as well, while perhaps gradually shifting
southeastward with time. Overall buoyancy and vertical shear will be
modest, but a few stronger cores capable isolated hail are possible.
Overall evolution of this early morning activity could lead to
either a sharpening of the warm front from the central KS vicinity
southeastward through northeast OK into western AR or potentially
southward/southwestward slow-moving outflow boundary. This sharp
boundary is expected to limit to eastern/northeastern extent of the
greater severe potential.

Farther west, persistent moisture advection is anticipated amid
moderate low-level southerly flow ahead of the approaching shortwave
trough. This is expected to result in mid 60s dewpoints by the
mid-afternoon across much of the eastern TX/OK Panhandle and OK,
with low 60s dewpoints reaching into south-central KS. Mid 60s
dewpoints are expected into western and south-central KS by early
evening. Steep mid-level lapse rates will exist a top this low-level
moisture, supporting moderate to strong buoyancy, with the
strengthening mid-level flow supporting robust deep-layer vertical
shear as well.

Some capping is anticipated along the dryline, but the combination
of strong diurnal heating (in the wake of morning clouds),
increasing large-scale ascent, and low-level convergence is expected
to result in convective initiation during the late afternoon. Widely
scattered to scattered thunderstorm coverage appears probable, with
storms quickly becoming severe after initiation. Large to very large
hail will be the primary threat with the initial development. The
tornado threat will also increase with any supercell that persists
into the evening, with low-level shear/SRH expected to increase with
time and eastward extent. As such any longer-lived supercells could
pose a strong tornado threat, particularly across
west-central/southwest KS where surface flow will be backed given
closer proximity of the surface low.

Additional thunderstorms are anticipated farther south Thursday
night as the Pacific front surges eastward. Highest storm coverage
currently appears most likely from southwest OK into northwest TX.
Initial development could produce large to very large hail before
then transitioning to a more linear mode. Some downstream severe
threat into north-central TX and south-central/central OK appears
likely, although uncertainty remains regarding overall intensity,
largely as a result of low-level nocturnal stability. However,
kinematic fields are quite strong and could maintain organized storm
structures capable of all severe hazards eastward into north-central
TX and south-central/central OK. This area will be assessed for
increased severe probabilities in later outlooks.

...Central High Plains into Nebraska...
Numerous thunderstorms are expected to develop from northeast CO/NE
Panhandle northeastward into NE Thursday night as large-scale ascent
spreads across the region. Most of this activity will be elevated,
but the presence of steep mid-level lapse rates and moderate
vertical shear suggests large hail is possible with these storms,
with perhaps even some very large hail (i.e. 2 to 2.5" in diameter)
in the CO/NE/KS border vicinity where surface-based parcels are
possible.

...Eastern WY into Southwest SD...
Moderate buoyancy will support scattered diurnal thunderstorm
development into the Black Hills vicinity. Deep-layer shear will be
weaker in this area than areas farther south, but may still be
sufficient for modestly organized storms capable of large hail.

..Mosier.. 04/24/2024

$$