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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



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