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ACUS02 KWNS 300551

SWODY2

SPC AC 300549



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1249 AM CDT Tue Apr 30 2024



Valid 011200Z - 021200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE

CENTRAL PLAINS...WITH SCATTERED SEVERE STORMS FROM WESTERN TEXAS

INTO SOUTHERN NEBRASKA...



...SUMMARY...

Scattered severe thunderstorms will be possible across parts of the

central and southern Plains on Wednesday. A few tornadoes (including

potential for a strong tornado), very large hail and damaging winds

are expected.



...Synopsis...

On Wednesday, an upper trough will extend from MT into the Great

Basin by late afternoon, with increasing west/southwest flow aloft

spreading into the central and northern Plains. Height falls with

this trough will occur mainly overnight and into Thursday morning

over the Plains, with 500 mb southwesterlies increasing all the

while. Farther south, modest midlevel westerlies will exist from

western TX into northern Mexico, the upper-level winds more

prominent at over 60 kt at 300 mb.



At the surface, low pressure will deepen over the central High

Plains in advance of the upper trough, with a warm front lifting

north across KS during the day. This front will reach into far

southern NE during the late evening and overnight, with 60s F

dewpoints possibly reaching I-80 into eastern NE by 12Z Thursday.

Backed surface winds north of the warm front will also lead to

rising dewpoints into western KS and far eastern CO toward the low,

while robust moisture builds east of the dryline from southwest KS

into western TX. 



Aiding both moisture advection and shear will be an increasing

low-level jet which will exceed 50 kt Wednesday evening, affecting

the majority of the central and southern Plains. Finally, a cold

front will move into western NE and KS by around 06Z, and surge east

toward the MO Valley into Thursday morning, augmented with

thunderstorm outflow.



...Central Plains...

Several possible severe-weather regimes may occur Wednesday into

Wednesday night, with initial activity expected along the warm front

during the day from south-central into eastern KS. This early

activity will begin elevated, but instability may be strong and

support occasional hail. With time, additional activity could

develop along any outflow boundaries as theta-e advection persists,

and a few surface-based cells may result by afternoon with hail or

tornado risk. 



Later in the day and coincident with peak heating, widely spaced

supercells are anticipated along the dryline from western KS into

northwest TX. Given that this area will be well ahead of the upper

trough, large-scale support will be minimal.  However, strong

heating and mid to upper 60s F dewpoints will still lead to at least

isolated supercells capable of very large hail, and tornado risk

within a relatively narrow zone. 



Farther north, the plume of backed moisture may lead to storms

developing over eastern CO into western KS.  This convection will

eventually interact with the cold front by late evening. Depending

on how uncapped the air mass is at that time, cells may congeal into

a line of storms, which will be limited on the northern end by

cooler air into NE, and on the southern end by possible capping.

However, with very steep lapse rates aloft, a strong low-level jet

and the frontal forcing, a few significant wind gusts cannot be

ruled out along the NE/KS border overnight. 



...Western TX...

Strong heating will occur near the dryline, where an uncapped and

very unstable air mass will develop. As dewpoints rise well into the

60s F, MLCAPE may exceed 4000 J/kg. Ample low-level convergence

along the boundary will lead to scattered afternoon storms, some of

which will be slow-moving supercells. Increasing and backing 850 mb

winds with time may support a few east/southeast cell motions, with

localized very large hail. In addition, hail-laden outflows may lead

to wind damage.



..Jewell.. 04/30/2024



$$