####018002667####
ACUS48 KWNS 280901

SWOD48

SPC AC 280859



Day 4-8 Convective Outlook  

NWS Storm Prediction Center Norman OK

0359 AM CDT Sun Apr 28 2024



Valid 011200Z - 061200Z



...DISCUSSION...

...D4/Wednesday - Central and southern Plains...

Extended-range guidance generally depicts a broad upper-level trough

gradually moving eastward across the western CONUS on Wednesday,

though differences remain regarding the amplitude of this trough.

Downstream of the trough, a surface low is forecast to deepen across

the south-central High Plains, with rich low-level moisture

streaming northward along/east of a developing dryline and south of

a northward-moving warm front. Moderate to strong buoyancy may

develop across the warm sector Wednesday afternoon, and scattered

thunderstorm development will be possible along/east of the dryline

and also near the warm front. 



While mid/upper-level flow is currently forecast to remain rather

modest, deep-layer shear may be sufficient to support some organized

convection. With most extended-range guidance depicting scattered

thunderstorm development during the afternoon and evening within a

relatively favorable environment, a 15% area has been added for

parts of the central/southern Plains, where confidence in an

organized severe threat is currently highest.



Some guidance suggests the threat could extend into parts of

southwest and deep south TX, in advance of a low-amplitude

subtropical shortwave trough, though uncertainty remains rather high

regarding this potential.  



...D5/Thursday - Central and southern Plains into the MS Valley...

A continuation of severe potential is expected into Thursday across

parts of the central/southern Plains and potentially into the

mid/upper MS Valley, with moderate to locally strong instability

expected again during the afternoon across the warm sector of a

northeastward-moving cyclone. However, predictability begins to

decrease at this forecast range regarding timing of a cold front

that is forecast to move southeastward and potentially provide a

focus for thunderstorm development during the afternoon and evening.



...D6/Friday - D8/Sunday...

A notable increase in spread amongst extended-range guidance is

noted by D6/Friday into the weekend. In general, a cold front will

likely continue moving southeastward before stalling across parts of

southern Plains into the Southeast. Rich low-level moisture and

stronger instability may be maintained across parts of TX, but

organized severe potential in that area remains very uncertain at

this time.



..Dean.. 04/28/2024