099
ACUS01 KWNS 040528
SWODY1
SPC AC 040527

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 AM CDT Sat Oct 04 2025

Valid 041200Z - 051200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
ROCKIES INTO THE NORTHERN PLAINS...

...SUMMARY...
Isolated severe wind gusts/hail may accompany the stronger
thunderstorms across the central Rockies into the northern High
Plains late this afternoon and evening.

...Central Rockies to northern Plains...

Upper low over southern NV will begin to eject northeast over the
next few hours, advancing into UT by 12z then open up as a
progressive short-wave trough over WY/CO by early evening. This
feature will move into the eastern Dakotas overnight as 500mb speed
max intensifies and translates toward the upper Red River Valley by
05/12z. At the surface, synoptic front is expected to move very
little, extending from southeast MB-eastern ND-southeast WY.

While strong boundary-layer heating is forecast across the high
Plains into southeast SD, instability should remain weak despite
steep 0-3km lapse rates. Isolated thunderstorms should develop ahead
of the short wave across southeast WY/NE Panhandle into western SD,
but forecast soundings suggest hail will struggle to be more than
marginally severe. Some gust potential exists where lapse rates are
steep. More concentrated robust updrafts are expected along the cool
side of the boundary from northern SD into eastern ND/northwest MN
during the latter half of the period. Forecast soundings suggest the
most buoyant parcels will be rooted near 850mb where MUCAPE could
exceed 1500 J/kg. This post-frontal convection will be aided by a
strengthening LLJ which should encourage some organization,
especially given the approaching short wave. This activity will be
focused mostly after sunset and hail could exceed 1 inch in the
strongest elevated updrafts.

..Darrow/Lyons.. 10/04/2025

$$