From Mike Powell@618:250/1 to All on Wed Apr 16 08:40:00 2025
ACUS48 KWNS 160853
SWOD48
SPC AC 160851
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0351 AM CDT Wed Apr 16 2025
Valid 191200Z - 241200Z
...DISCUSSION...
Severe potential remains apparent into the weekend, but
predictability wanes substantially by D5/Sunday.
...D4/Saturday...
The persistent longwave trough is expected to breakdown as an
embedded northern-stream shortwave impulse accelerates east across
ON/QC and the basal shortwave impulse moves more gradually east into
the southern High Plains. Through Saturday afternoon, an expansive
swath of strong mid-level flow will persist from the central
Appalachians southwestward into the southern Great Plains. The
nearly stalled baroclinic zone from TX/OK into the Lower OH Valley
will likely be modulated by ongoing convection on Saturday morning.
But with appreciable boundary-layer heating of a seasonably moist
air mass to the south-southeast, scattered severe storms are
plausible from the Upper OH Valley through central TX.
...D5/Sunday...
The 00Z GFS and related GEFS are substantially different relative to
24 hours ago with the evolution of the compact shortwave trough
ejecting across the southern Great Plains and the attendant synoptic
cyclone. Most other guidance has remained relatively consistent to
prior days with probable cyclogenesis from OK to the Lower MO
Valley. This would result in a confined belt of strong mid-level southwesterlies overlapping a broad warm sector with rich western
Gulf moisture. Potentially extensive convection in parts of OK/TX on
Sunday morning does complicate exactly how far north-northwest
appreciable destabilization may occur into the Ozarks/Lower MO
Valley and beyond. Overall setup outside of the GFS-based guidance
appears to support scattered severe storms across the South-Central
States on Sunday afternoon/evening.