003
ACUS48 KWNS 150859
SWOD48
SPC AC 150858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Thu May 15 2025

Valid 181200Z - 231200Z

...DISCUSSION...
Medium-range guidance indicates that the persistent, prominent
mid/upper ridging across the mid-latitude and subtropical eastern
Pacific will become suppressed late this coming weekend into early
next week, before breaking down through the remainder of this
period.  As it does, amplified downstream troughing is forecast to
emerge from the Intermountain West.  Sunday, this may commence
gradually, with one significant lead short wave perturbation
pivoting north-northeast of the southern Rockies, accompanied by
cyclogenesis across eastern Colorado, as an upstream perturbation
continues to dig toward the Four Corners region.  It appears that
this trailing perturbation will then pivot across the southern
Rockies through the central/southern Great Plains by late Monday,
perhaps accompanied by renewed cyclogenesis across the Texas
Panhandle into central Great Plains.

Both days, the dryline and warm front may provide focus for
organized severe convective development, including supercells, in
the presence of strong deep-layer shear and thermodynamic profiles
characterized by steep lapse rates and sizable CAPE.  It appears
that a substantive risk for strong to severe thunderstorms will
persist into at least Tuesday, within a broadening warm sector as
the cyclone and associated mid-level troughing shift a bit more
rapidly eastward across the middle Mississippi Valley.

Convective potential becomes more unclear Wednesday into Thursday as
the cyclone likely weakens and synoptic developments become more
uncertain across the East.

..Kerr.. 05/15/2025