257
ACUS01 KWNS 011213
SWODY1
SPC AC 011212

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0712 AM CDT Tue Sep 01 2026

Valid 011300Z - 021200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
OVER PARTS OF THE NORTHEAST STATES...AND THIS EVENING OVER THE
CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST....

...SUMMARY...
Scattered strong to severe storms are possible over the central
Plains and Midwest, as well as parts of New York, Pennsylvania and
New Jersey.

...Northeast...
A broad upper ridge remains in place over the Mid MS/TN Valleys,
with northwest flow aloft affecting the northeast US and
Mid-Atlantic states.  The main baroclinic zone in this region
currently extends from central NY into southern New England, with
dewpoints in the mid-upper 60s along and south of the boundary. This
air mass is expected to destabilize through the day as temperatures
warm through the 80s, leading to a zone of strong instability
(MLCAPE of 2500+ J/kg) over parts of PA/NY/NJ.  Ongoing convection
may delay daytime heating, but eventually strong storms are expected
to form in this region, spreading southeastward through the late
afternoon and evening.  Damaging winds are the primary concern,
although some hail and a tornado or two cannot be ruled out.  A lack
of a more obvious upper feature to aid in large-scale forcing may
limit the overall coverage of severe storms.

...SD/NE/MN/IA...
A shortwave trough currently over western CO will track quickly
northeastward and affect the central Plains by late afternoon.
Strong heating and a moist air mass will yield moderate CAPE over
parts of SD/NE.  Low-level warm advection and diurnal heating will
lead to scattered thunderstorm development over central SD by late
afternoon.  Initial supercell storms are expected, capable of
damaging winds, large hail, and perhaps a tornado.  Storms are
expected to become more numerous during the evening and grow upscale
into bowing structures, with a damaging wind risk tracking eastward
into parts of southern MN and perhaps northern IA.  Some guidance
suggests storms will maintain some damaging wind risk into central
WI overnight.

...Southwest LA/Southeast TX...
Tropical Storm Eduardo is expected to strengthen today off the
immediate LA/TX coast and move inland this afternoon and evening.
Models continue to show limited discrete convection in the northeast
quadrant of the system, suggested a rather low tornado risk today.
Nevertheless, given the potential for rapid strengthening around the
time of landfall, have opted for a small 2% tornado risk area for a
few hours this evening.

..Hart/Dean.. 09/01/2026

$$