505 
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


File: /opt/ldm/var/data/BY_SOURCE/KWNS/ACUS48/20240428T0901.txt