572
ACUS02 KWNS 271730
SWODY2
SPC AC 271728

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Sun Sep 27 2026

Valid 281200Z - 291200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorm probability remains low on Monday.

...Synopsis...
The broad western trough will evolve into an upper low over the
Lower Colorado Valley with a low-amplitude trough over the northern
Rockies on Monday. Low-level moisture will be maintained into the
northern Plains by persistent low-level southerly flow. A cold front
will eventually move southeast through parts of the Dakotas by
Tuesday morning.

...Northwest South Dakota Vicinity...
Precipitation associated with low-level jet warm advection will
likely be ongoing in the morning. Ahead of a low-amplitude trough in
the northern Rockies, a weak surface trough/broad cyclone is
expected to develop near the Wyoming/South Dakota border and move
east-northeast through the afternoon/early evening. Despite
increasing mid/high-level clouds, some filtered surface
heating/destabilization is possible. Some CAM guidance suggests a
narrow zone in time and space for storm development is possible
along the surface trough by late afternoon. While the environment
could conditionally support a strong to marginally severe storm or
two, development/coverage remains uncertain given the modest warming
aloft that will occur during much of the period as well as weak
low/mid-level forcing for ascent. It is more probable that
convection develops along the advancing cold front well after 00Z as
the low-level jet intensifies. By that time, the thermodynamic
environment will be less favorable for severe storms.

..Wendt.. 09/27/2026

$$