ACUS48 KWNS 090901

SWOD48

SPC AC 090859



Day 4-8 Convective Outlook  

NWS Storm Prediction Center Norman OK

0359 AM CDT Fri May 09 2025



Valid 121200Z - 171200Z



...DISCUSSION...

Based on the latest medium-range guidance, it appears that

large-scale mid/upper troughing will continue digging inland of the

Pacific coast, before gradually turning eastward toward the Rockies

during the early portion of next week.  While this probably will be

accompanied by the development of modestly deep surface troughing

across the Great Plains, appreciable low-level moisture return, in

the wake of a mid-level low/trough slowly accelerating northeast of

the lower Mississippi Valley, through parts of the Mid South and

Ohio Valley, remains uncertain.



Even into mid-week, when it appears that the troughing may begin to

emerge from the Intermountain West/Rockies, while the downstream

troughing only slowly progresses across the Mid Atlantic, moisture

return (and destabilization) to the vicinity of the stronger forcing

for ascent may remain a potential limiting factor to severe

thunderstorm development.



Toward next Thursday/Friday, there does appear consensus that

stronger destabilization may begin to become better coupled with

large-scale forcing for ascent across the upper Mississippi

Valley/Midwest into Ohio Valley, as the mid-level troughing

progresses northeastward and eastward, around the periphery of

mid/upper ridging building north-northeast of the lower Mississippi

Valley.  This appears to include at least a conditional risk for

organized severe convection, including a few supercells.  Although

lingering uncertainties preclude introducing 15 percent or greater

severe probabilities at this time, this may change in later outlooks

for this period.



..Kerr.. 05/09/2025