761
ACUS48 KWNS 030818
SWOD48
SPC AC 030817

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0317 AM CDT Wed Sep 03 2025

Valid 061200Z - 111200Z

...DISCUSSION...
The western North American midlevel ridge of the previous days will
slowly move east into the central continent by the end of the
forecast period and in its place an amplified longwave trough will
take hold across the western US.

... Saturday/Day-4 ...
Before this transition happens, a seasonably strong cold front will
push east into the Atlantic and south into the northern Gulf states
as an expansive surface high will move into the central US on
Saturday/Day-4. Guidance disagrees to the degree instability will
materialize along and ahead of the front from the Mid-Atlantic
region into New England. However, pattern recognition would support
scattered strong thunderstorms along the front across this region.
Midlevel flow will be sufficiently strong to support at least some
damaging wind potential should thunderstorms develop.

... Sunday/Day-5 through Wednesday/Day-8 ...

A seasonably cool, dry continental airmass will be in place across
much of the eastern two-thirds of the contiguous US, resulting in
low potential of organized severe thunderstorms on Sunday/Day-5.
That said, as the western trough takes hold, lee troughing will
develop across the High Plains. This will result in return flow
drawing low-level northward by early next week. Weak shortwave
troughs/vorticity maxima embedded in the increasingly southwesterly
flow may yield thunderstorms across the High Plains during the late
afternoon into the overnight hours. Depending on the quality of the
resulting low-level moisture return and the strength of any of these
shortwave troughs, the potential for organized severe thunderstorms
may develop, especially later in the forecast period. However,
predictability of these features at this time scale is too low to
warrant unconditional probabilities at this time.

..Marsh.. 09/03/2025