171
ACUS48 KWNS 110901
SWOD48
SPC AC 110859

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Fri Sep 11 2026

Valid 141200Z - 191200Z

...DISCUSSION...
Medium-range guidance indicates that a remnant cyclonic circulation
and associated mid-level troughing, likely accelerating across the
northern U.S. Rockies and adjacent international border vicinity by
early Monday, may be accompanied by substantive surface cyclogenesis
across southern Manitoba through northwestern Ontario Monday through
Monday night, before continuing east-northeastward into the higher
latitudes.  It appears that this will occur coincident with the
transition to a more progressive regime across the northern
mid-latitude Pacific, including the gradual suppression of a
blocking high initially to the southeast of the Aleutians.  It also
appears likely to coincide with the redevelopment of rather
prominent mid/upper ridging becoming centered across the Tennessee
Valley/southern Appalachians vicinity, and increasingly influential
across much of the central and eastern U.S. into the middle to
latter portions of next week, before becoming suppressed and
retrograding west-southwestward.

In association with this regime, although there is some uncertainty
concerning low-level moisture return and destabilization, it still
appears that an evolving warm frontal zone could become a focus for
organized strong to severe thunderstorm development across parts of
the middle Missouri Valley toward Upper Midwest late Monday
afternoon into Monday night.  Thereafter, the potential for
organized severe thunderstorm development appears generally low,
though there may still be areas of strong storm development with
rather isolated or marginal severe weather potential.

..Kerr.. 09/11/2026