644
ACUS02 KWNS 171728
SWODY2
SPC AC 171727

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 PM CDT Mon Aug 17 2026

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
KANSAS...CENTRAL TO SOUTHEAST NEBRASKA...SOUTHWEST IOWA...AND
NORTHWEST MISSOURI...

...SUMMARY...
Severe thunderstorms capable of large hail and damaging wind gusts
are expected Tuesday afternoon/evening across parts of the central
Plains and toward the Lower Missouri/Mid-Mississippi Valley.

...Central Plains to Mid/Upper MS Valley...
The presence, or lack, of morning convection will have a significant
impact on the evolution of storms on Tuesday. From the 12Z HREF
cycle, a majority of the CAM members have a cluster of storms across
eastern Nebraska at 12Z. Given the environment in the region, this
cluster would at least have some marginal hail/wind threat. Most
guidance has this cluster dissipating as the low-level jet weakens.
Given a more stable environment east of this activity this seems
like the most likely scenario. If this cluster can persist until
late morning when the downstream airmass destabilizes to the south,
it could turn right and persist across Missouri, but evidence for
this is quite low.

Whatever boundaries any morning storms leave behind will likely be
the focus for diurnal storm development. Overall forcing is quite
low which may lead to isolated to widely scattered storm
development. However, 45 to 55 knots of mid-level flow from the
KS/NE border northward will provide ample shear for storm
organization, including supercells. In fact, some 2-3 inch hail
seems likely with any longer-lived supercells which may develop
within this most favorable environment.

Additional thunderstorms are expected during the overnight period
from northern Kansas to central Missouri, within a region of
isentropic ascent. The location of the 850mb front and the best
forcing still has some uncertainty, but thunderstorm activity will
be most likely from northeast Kansas to northwest Missouri. As
storms congeal and a cold pool forms, a wind-producing MCS may
develop out of this cluster. This is most prominently shown by the
WRF-NSSL and the WRF-ARW. Therefore, a CIG1 wind intensity has been
added across this region for this conditional 75+ mph wind threat
associated with a MCS in the forecast environment.

..Bentley.. 08/17/2026

$$