712
ACUS01 KWNS 111614
SWODY1
SPC AC 111612

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 AM CDT Mon Aug 11 2025

Valid 111630Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER
MIDWEST...

...SUMMARY...
Isolated strong to severe thunderstorms are possible across parts of
the southern Plains, lower Missouri Valley, and the Upper Midwest,
mainly this afternoon and evening.

...Lower MO Valley...
Visible satellite/radar composite shows an MCV moving
east-northeastward over northeast KS late this morning.  Regional
WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in
the 2-6 km layer) associated with this disturbance.  Surface
analysis places a surface low over the Flint Hills with backed
easterly flow across eastern KS into northwest MO.  Considerable
mid- to high-level cloud debris from early morning convection will
be slow to dissipate, but gradual filtering of sunlight and the
initial signs of a stratocumulus field over the Flint Hills
indicates destabilization is beginning to occur.  Models vary
considerably (understandably so) regarding the development/evolution
of a few potential stronger thunderstorms across the lower MO Valley
later this afternoon into the early evening.  Some forecast
soundings show modest enlargement of the low-level portion of the
hodograph, which may support updraft rotation if vigorous updraft
development occurs.  Given the low probability for severe and
potentially supportive environment, have introduced low-severe
probabilities this outlook update.

...Southern Plains...
Morning analysis shows an outflow reinforced front has advanced
southward across the southern High Plains, but has stalled near the
I-44 corridor in OK southwestward into the northern periphery of the
Permian Basin.  Water-vapor imagery shows a mid-level impulse moving
across southern CO and embedded within larger-scale troughing from
CO/NM into the Upper Midwest.  This mid-level trough will gradually
pivot eastward over the southern High Plains through the evening.
Heating of an adequately moist boundary layer (dewpoints ranging
from the lower 70s in central OK to the mid 50s in east-central NM)
will yield moderate buoyancy near/north of the diffuse boundary.
Weak low-level winds will gradually veer to west-northwesterly and
modestly strengthen with height through mid/upper levels, supporting
modest deep-layer shear and some updraft organization.

Isolated severe hail may occur with initially more cellular
development across the southern High Plains, before some clustering
potentially occurs late this afternoon/evening farther east into the
TX Panhandle and northwest TX with more of a wind threat.  While
deep-layer shear will likely remain weak farther east across OK, the
front/outflow boundary should aid in at least scattered
thunderstorms.  Isolated large hail and severe gusts are the primary
hazards with the stronger thunderstorms.

...North Dakota into Northern Minnesota...
No change in thinking from the previous forecast.  A mid-level
shortwave trough and related surface cold front are forecast to move
east-southeastward over ND and northern MN through the period.
Modest low-level moisture characterized by mid 50s to perhaps low
60s surface dewpoints should be present ahead of the front across
these areas. Diurnal heating and modestly steepened lapse rates
aloft should aid in the development of weak instability this
afternoon.  Thunderstorms should gradually increase in coverage
along/ahead of the front this afternoon/evening as they spread
eastward over parts of ND into northern MN. The stronger cells may
produce marginally severe hail, with sufficient deep-layer shear
present for some convective organization. With time, some
clustering/upscale growth along the front appears probable, with
isolated strong to severe gusts possible. The lack of stronger
instability should tend to temper the overall severe threat.

..Smith/Squitieri.. 08/11/2025

$$