597
ACUS48 KWNS 180736
SWOD48
SPC AC 180734

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0234 AM CDT Fri Apr 18 2025

Valid 211200Z - 261200Z

...DISCUSSION...
An upper shortwave trough will weaken as it spreads east/northeast
from the Mid/Upper MS Valley to the Lower Great Lakes on Day 4/Mon.
The associated surface low will likewise shift northeast from
eastern IA/IL into Ontario, while a trailing cold front moves across
much of the Midwest. Modest boundary-layer moisture will aid in weak
destabilization and some low-end severe thunderstorm risk could
develop across parts of the Ohio Valley/Lower Great Lakes vicinity.
The southern extent of this front will stall across the Mid-South
and Sabine Valley. Richer low-level moisture ahead of the surface
boundary across parts of the South could support some thunderstorm
risk as well, but nebulous forcing and weak vertical shear will
limit severe potential.

On Days 5-8/Tue-Fri, a low-amplitude, weak flow pattern is forecast.
Southerly low-level flow across the Gulf and southern Plains will
allow for northward moisture transport across OK/TX and vicinity.
Diurnal thunderstorm activity could be possible each day given
modest west/southwest flow atop a moist warm sector. However, a
rather nondescript surface pattern amid weak large-scale forcing
will likely preclude widespread severe potential, though localized
areas of severe storms could still occur given favorable
moisture/instability, particularly along any dryline features.

..Leitman.. 04/18/2025