610
ACUS02 KWNS 031652
SWODY2
SPC AC 031650

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1150 AM CDT Fri Oct 03 2025

Valid 041200Z - 051200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
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 tomorrow (Saturday).

...Synopsis...
Broad upper troughing will take place across the western and central
U.S., while upper riding perseveres over the eastern CONUS tomorrow
(Saturday). A pronounced embedded mid-level impulse will eject into
the northern Plains, supporting the deepening of a surface low over
SD by afternoon, with a second surface low likely developing over
western WY. Low-level moisture will advect northward ahead of the SD
surface low as a cold front approaches from the central/northern
High Plains. An unstable but capped airmass will characterize the
warm sector, with thunderstorm development most likely along and
behind the cold front by tomorrow evening. Given adequate vertical
wind shear, a few of these storms may be severe across the central
Rockies into the northern Plains.

...Central Rockies into the central High Plains...
Thunderstorms are expected to develop by afternoon in association
with the western (WY) surface low, atop a mixed boundary layer.
Instability will be marginal over the central Rockies toward the
central High Plains (e.g. less than 500 J/kg MLCAPE). However,
rapidly strengthening winds with height will support strong speed
shear. As such, multicells with an isolated severe wind/hail threat
will exist across the central Rockies into the central High Plains
during the afternoon hours.

...Northern High Plains...
By afternoon peak heating, ahead of the cold front, surface
temperatures will likely reach into the upper 80s F, amid low 60s F
dewpoints across the northern Plains. Across the warm sector,
1000-2500 J/kg MLCAPE is expected, with the higher values of MLCAPE
constrained to the eastern Dakotas and MN, where richer low-level
moisture will be. Deep-layer forcing for ascent, needed to support
thunderstorm development against appreciable MLCINH, will be
displaced to the west, closer to and behind the surface cold front.
As forcing gradually overspreads the northern Plains/cold front
during the evening, thunderstorms should develop along/immediately
behind the cold front. Given strong speed shear parallel to the
front, the stronger linear segments will be capable of isolated
severe gusts and perhaps an instance of hail Saturday evening and
overnight.

..Squitieri.. 10/03/2025

$$