Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0712 AM CDT Thu Sep 03 2026

Valid 031300Z - 041200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY THROUGH
TONIGHT ACROSS PARTS OF THE SOUTHERN GREAT LAKES INTO MID ATLANTIC
AND PARTS OF THE NORTHERN GREAT PLAINS...

...SUMMARY...
Scattered strong thunderstorm development is likely today through
tonight, perhaps including a few organizing clusters, posing a risk
for severe wind and hail across parts of the southern Great Lakes
into Mid Atlantic and portions of the northern Great Plains into
Upper Midwest.

...PA to Delmarva...
A broad upper ridge remains over the TN Valley, with fast zonal flow
stretching across the Great Lakes into the Mid-Atlantic region. 
Multiple clusters of thunderstorms are ongoing this morning over
western PA and northern MD.  These storms will progress
southeastward today across an air mass affected by storms last
evening, where there is uncertainty how much destabilization can
occur.  Damaging winds will be possible in those areas where
sufficient heating can occur, especially by early afternoon. 

...WI to PA...
A common scenario in recent CAM solutions is that a mid-level speed
max associated with convection over MN/IA will track across WI and
into Lower MI by mid/late afternoon.  Morning convection will result
in an outflow boundary from southeast WI into southern Lower MI,
likely providing the focus for rapid afternoon thunderstorm
development.  Ample low-level moisture/CAPE and favorable westerly
flow aloft suggest an initial risk of supercells, but increasing
linear organization with time.  Storms will track into northern
IN/OH by late afternoon, and eventually into western NY/PA this
evening.  Damaging wind gusts are the primary concern with this
activity.

...ND/MN...
Morning water vapor imagery suggests a strong shortwave trough
lifting northeastward across WY.  This feature will move into the
Dakotas today, aiding the development of intense thunderstorms over
eastern ND by mid-afternoon.  Initial supercells will be capable of
large hail and a tornado or two.  Activity will likely persist
through much of the evening, tracking eastward across parts of
northern/central MN and perhaps into northern WI.  Damaging winds
and hail would be the main concerns during that period.

..Hart/Dean.. 09/03/2026