066
ACUS03 KWNS 120722
SWODY3
SPC AC 120721

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0221 AM CDT Mon May 12 2025

Valid 141200Z - 151200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE
CENTRAL AND NORTHERN PLAINS...

...SUMMARY...
Isolated severe thunderstorms are possible across parts of the
central to northern Plains Wednesday afternoon and evening.

...Synopsis...
A progressive upper trough is forecast to pivot from the
Intermountain West into the northern Plains through the day
Wednesday. Ahead of this wave, an elongated surface trough draped
across the Plains will undergo consolidation as a surface cyclone
begins to organize over the Dakotas through the forecast period. The
arrival of a cold front coincident with the ejection of the upper
trough will provide an impetus for thunderstorm development across
the central to northern Plains during the afternoon and evening
hours. Further east, a weakening upper wave over the Mid-Atlantic
will continue to slowly lift to the northeast. A combination of cold
temperatures aloft, moist low-level conditions, and modest
broad-scale ascent will promote widespread showers and weak
thunderstorms across the upper OH River Valley and Mid-Atlantic
region.

...Central/Northern Plains...
A somewhat expansive warm sector will become established across much
of the Plains through the day Wednesday; however, the eastward
advection of a strong EML will hinder convective development for
much of the southern and central Plains. Although moisture return
into the northern Plains will be somewhat modest compared to
locations further south (dewpoints only reaching the mid to upper
50s), strong deep-layer ascent ahead of the approaching wave and
within the left-exit region of the attendant mid-level jet will
sufficiently erode residual capping by late afternoon to promote
thunderstorm initiation along the cold front within an unstable air
mass. The favorable thermodynamic and kinematic environment should
promote a few strong/severe storms capable of severe hail/wind,
though deep-layer shear vectors and initial storm motions largely
parallel to the front will promote quick upscale growth into one or
more convective clusters/line segments that may limit the overall
duration and coverage of the severe threat. A more prolonged, but
isolated, severe threat may materialize late evening into the
overnight hours within the MO River Valley as isentropic ascent at
the terminus of the nocturnal jet increases and promotes additional
thunderstorm development - though model consensus regarding this
potential is limited at this range.

..Moore.. 05/12/2025

$$