619
ACUS48 KWNS 100915
SWOD48
SPC AC 100914

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0314 AM CST Wed Dec 10 2025

Valid 131200Z - 181200Z

...DISCUSSION...
Based on the latest medium-range model output, a vigorous digging
short wave trough is likely to contribute to substantive mid-level
trough amplification once again across the Upper Midwest/Great Lakes
and Ohio Valley, into and across the Mid Atlantic Seaboard this
coming weekend.  It appears that this may provide support for
significant cyclogenesis along a frontal zone across the
northwestern Atlantic, while a strongly confluent mid-level regime
in its wake supports the southeastward development of a large cold
surface ridge across most areas east of the Rockies, including the
offshore Atlantic and Gulf Basin by early next week.

Thereafter, into the middle of next week, mid-level flow may trend a
bit more zonal, at least across the northern mid-latitudes of North
America.  However, there is notable spread evident within and among
the various model output concerning short waves emerging from the
upstream blocking pattern, before progressing inland within
splitting branches of westerlies across and east of the Rockies.
After an initial suppression of Gulf boundary-layer moistening early
next week, a developing southerly return flow with moistening that
may lead to increasing convective potential appears possible across
and northeast of the northwestern Gulf coast/lower Mississippi
Valley vicinity.  The extent to which this could include a risk for
severe storms remains unclear, but currently still appears generally
low through at least this period.

..Kerr.. 12/10/2025