815
ACUS48 KWNS 200804
SWOD48
SPC AC 200803

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0303 AM CDT Wed Aug 20 2025

Valid 231200Z - 281200Z

...DISCUSSION...
...D4/Saturday - D6/Monday...
On D4/Saturday, a seasonably strong cold front will move across
parts of the south-central Great Plains into the mid MS Valley and
southern Great Lakes region, as a deep mid/upper-level trough
becomes established over much of the central/eastern CONUS. Somewhat
favorable deep-layer flow/shear could support strong to locally
severe storms along the front, though generally modest instability
may tend to limit the magnitude of the severe threat. Strong storms
may also develop within a post-frontal regime across parts of the
central High Plains.

The cold front will make further south/east progress on D5/Sunday,
and locally strong storms may develop from parts of the Northeast
into the central/southern Appalachians. Generally weak instability
may tend to limit coverage of the organized severe threat. Strong
storms may also develop again within a post-frontal regime across
parts of the central/southern High Plains.

The cold front may tend to slow down by D6/Monday across parts of
the Mid Atlantic and Northeast, though guidance begins to diverge
regarding the evolution of the deep upper trough and potential for
surface low development off of the Mid Atlantic coast. Some
potential for strong storms could again evolve along the front, from
parts of New England into the Mid Atlantic.

...D7/Tuesday - D8/Wednesday...
While predictability continues to wane regarding the details,
extended-range guidance generally depicts persistence of the eastern
CONUS upper trough into the middle of next week, though it may begin
to shift eastward with time. In the wake of the cold frontal
passage, an expansive surface ridge is forecast to maintain
generally stable conditions for most areas east of the Rockies,
resulting in limited potential for organized severe storms.

..Dean.. 08/20/2025