927
ACUS02 KWNS 301736
SWODY2
SPC AC 301734

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 PM CDT Tue Apr 30 2024

Valid 011200Z - 021200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN A PART OF
SOUTHWEST KS TO NORTHWEST OK...

...SUMMARY...
Scattered severe thunderstorms are possible across parts of the
central and southern Great Plains from Wednesday afternoon into
Wednesday night. A few tornadoes, very large hail, and damaging
winds are anticipated.

...Synopsis...
In the wake of a vigorous shortwave trough moving across the Upper
Great Lakes to the Saint Lawrence Valley, an upstream shortwave
impulse will gradually shift east from the northern Rockies to the
northern High Plains. The initial cold front on D1 over the central
Great Plains will stall and advance north as a warm front Wednesday
night. Convective outflows from residual D1/early D2 convection
should exist south of this boundary in parts of OK.

...Central Great Plains...
Consensus of guidance continues to trend south with the placement of
the quasi-stationary front expected to be lying across southern KS
at 12Z Wednesday. A pronounced low-level jet should restrengthen
during the day, which will probably yield a swath of elevated
convection spreading northeast across the Mid-MO Valley with perhaps
a marginal severe hail threat. How far north the front will advance
during the day is uncertain with above-average spread across
guidance, but near its intersection with the surface dryline in the
southwest to west-central KS vicinity should be the most favorable
combination of the thermodynamic/kinematic environment. With
near-neutral mid-level height change through early evening,
convergence along the dryline will be necessary for late afternoon
thunderstorm development. Guidance largely suggests convective
coverage will remain isolated at most. But within a highly favorable
environment for supercells, tornadoes and very large hail will be
possible.

On Wednesday evening into the night, the plume of returning
low-level moisture coupled with increasing large-scale ascent
downstream of the northern Rockies to High Plains should lead to
largely elevated storms developing in the CO/NE/KS border vicinity.
Much of this convection should remain north-northwest of the surface
warm front and likely remain elevated until very late in the period.
But with very steep lapse rates aloft, a strong low-level jet and
strong forcing for ascent, an elevated MCS capable of producing both
large hail and severe surface wind gusts remains possible.

...Southern Great Plains...
Strong heating will occur near the dryline, where an uncapped and
very unstable air mass will develop with MLCAPE of 3000-3500 J/kg.
Bulk of guidance suggests appreciable convective development will
occur in west TX, where a minor mid-level impulse may emerge within
the modest southern-stream flow regime. More isolated dryline storms
should form farther north, perhaps intersecting with residual
outflows from remnant convection in OK on Wednesday morning.

Deep-layer shear compared to early May climo will be relatively
modest, but the ample buoyancy coupled with numerous storms should
yield a mixed cluster and transient/slow-moving supercell mode.
Large to significant severe hail and sporadic severe wind gusts will
be possible. Potential will exist for upscale growth into
slow-moving clusters that move east into central parts of TX during
the evening and likely linger overnight, with a gradually subsiding
severe threat during these time frames.

..Grams.. 04/30/2024

$$