ACUS02 KWNS 200600
SWODY2
SPC AC 200559

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Sat Sep 20 2025

Valid 211200Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE OHIO VALLEY AND GREAT LAKES...

...SUMMARY...
A few strong to severe thunderstorms are possible across parts of
the Ohio Valley and Great Lakes on Sunday.

...Synopsis...
A mid-level trough will exist across the Upper Midwest on Sunday
with multiple mid-level shortwave troughs extending within mostly
zonal flow from the Mid-Atlantic to the central Rockies. A split
flow pattern will exist along the West Coast with a trough across
the Pacific Northwest and off the southern California coast. A
surface low will exist off the East Coast. Otherwise, the surface
pattern will be nebulous with weak lee troughing along the central
and northern Plains. A weak surface low may be present across the
western Great Lakes, ahead of the mid-level shortwave trough.

...Ohio Valley into the Great Lakes...
Weak to moderate instability is forecast across the Ohio Valley and
into the Great Lakes where mid 60s dewpoints will be present.
Forecast soundings show minimal inhibition by mid afternoon with
weak height falls across the warm sector. CAM guidance consistently
shows scattered thunderstorm development Sunday afternoon/evening
across the Ohio Valley/Great Lakes associated with a fast-moving
mid-level shortwave trough. A belt of stronger mid-level flow (35 to
40 knots) is forecast to overspread the warm sector during the
afternoon/evening. This will lead to increasing deep-layer shear
which would aid in storm organization. A few strong to severe storms
capable of damaging wind gusts are possible Sunday
afternoon/evening.

...OK/KS Vicinity...
A cluster of storms will likely be ongoing at the beginning of the
period across Oklahoma. If sufficient destabilization can occur
ahead of this cluster, a few strong storms could develop Sunday
afternoon/evening. In addition, a weak mid-level shortwave trough
(convectively enhanced by Day 1 convection across the central
Rockies) may move across Kansas Sunday afternoon. However, given the
low-amplitude nature of this wave and its dependence on Day 1
convection, considerable uncertainty in the amplitude and timing of
this mid-level shortwave trough exists. This precludes the addition
of severe weather probabilities at this time, despite a somewhat
favorable thermodynamic environment and potentially favorable shear
if mid-level flow enhancement overspreads the same area.

..Bentley.. 09/20/2025

$$
--- SBBSecho 3.28-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)