420 

ACUS02 KWNS 170526
SWODY2
SPC AC 170525

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1225 AM CDT Fri Apr 17 2026

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER OHIO RIVER VALLEY....

...SUMMARY...
Scattered strong to severe thunderstorms capable of damaging winds
and hail will be possible on Saturday across the upper Ohio Valley.

...Synopsis...
A mid-level trough will move from the Upper Midwest to the Great
Lakes on Friday. A surface cold front will move from the Great
Lakes/Ohio Valley to the Appalachians. In its wake, high pressure
will build into the Intermountain West and Plains.

Remnant showers/storms will likely be ongoing at the beginning of
the period ahead of the cold front. The extensive cloudcover and
potential outflow from Day 1 storms has resulted in considerable
uncertainty for the Saturday forecast. Most 00Z guidance shows
extensive outflow moving across Ohio during the morning. If this
occurs, additional storm development is not anticipated until
farther east across western Pennsylvania and southwest New York. If
these morning storms/outflow are less progressive, some moisture
advection ahead of the cold front is expected to bring somewhat
greater instability. This could result in some stronger storms, and
potentially sufficient instability for some transient supercell
structures.

Some 00Z CAM guidance (NAM/NSSL WRF) depicts low to mid 60s
dewpoints across eastern Ohio and western Pennsylvania on Saturday
afternoon. This seems to be the outlier, but if this does occur, a
more substantial severe weather threat, and a greater tornado threat
would exist across western Pennsylvania into southwest New York.
However, only weak instability seems most likely within this zone of
strong shear and therefore, expect damaging wind gusts as the
primary hazard.

..Bentley.. 04/17/2026

$$