739
ACUS48 KWNS 230840
SWOD48
SPC AC 230838

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0338 AM CDT Sun Aug 23 2026

Valid 261200Z - 311200Z

...DISCUSSION...
...D4/Wednesday to D6/Friday...
A mid-level trough will amplify across the Great Lakes region while
the mid-level ridge maintains its amplitude across the Rockies.
Within this pattern, some severe weather potential may exist as a
cold front moves from the Great Lakes to the Northeast. However, the
signal is not that strong and thus, it is unclear if more than an
isolated threat will exist; but the evolution of this front and the
instability associated with it will be monitored.

...D7/Saturday to D8/Sunday...
There is still a fair amount of uncertainty with the evolution of
the pattern by next weekend, but a general trend toward flattening
of the upper-level ridge is apparent in the deterministic, AI, and
ensemble guidance next weekend. This includes moderate flow within
the zonal region across the central/northern Plains and into the
Upper Midwest. This period will need to be watched closely as strong
instability and moderate shear appear to overlap across a relatively
broad region, which should support diurnal thunderstorm activity
given the flattening of the ridge. The specific timing/location of
these threats will depend on evolution of the pattern and the
embedded shortwave troughs within the flow. However, it is worth
noting that the EC-AIFS and the AIGFS both have a signal for a more
consolidated mid-level shortwave trough moving across the northern
Plains on Sunday/D8, which has also been consistently shown by the
EC-AIFS for the past 4 runs. If this trend continues, there may be
opportunities for probabilities to be added in later outlooks.

..Bentley.. 08/23/2026