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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



$$