Storm Prediction Center Day 2 Severe Weather Outlook

All data from the SPC

Day 3 Graphical Outlook

Definition: The probability values represent the chance of severe weather occurring within 25 miles of any point, which is approximately the size of a major metropolitan area.

Day 1 & 2: The outlook contains individual severe probabilities for tornadoes, wind, and hail.
Day 3: Due to greater uncertainty, the outlook only forecasts the combined probability of all three types of severe weather.

Context: Probabilities for severe thunderstorm wind and hail are typically higher than for tornadoes because they are more common. A 15% probability for a tornado means significantly above normal odds of a tornado nearby, which should be taken seriously, even though the number seems low.

Note: The peak daily tornado probabilities in the most tornado prone portions of the country (Plains and Southeast) are slightly above 2%. Therefore, most days with any tornado probabilities are well above climatology.


SPC Category Descriptions (Click image to enlarge)



Issue Times

Day 2 Outlook - Day 4-8 Outlook

Day 3 Outlook Discussion

SPC AC 131925

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0225 PM CDT Sun Sep 13 2026

   Valid 151200Z - 161200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
   PLAINS TO THE GREAT LAKES...

   ...SUMMARY...
   Scattered strong thunderstorms may impact a corridor south to
   southwest of the Great Lakes through the lower Missouri Valley
   Tuesday afternoon and evening, accompanied by at least some risk for
   locally damaging wind gusts.

   ...Discussion...
   A mid-level trough will move into Ontario on Tuesday with the
   mid-level ridge building in its wake across the Midwest and into the
   Upper Midwest. Beneath this ridge, a cold front will move slowly
   southeastward from southern Iowa and northern Kansas at the
   beginning of the period, to northern Oklahoma to central Missouri by
   the end of the period. Dewpoints will increase into the low to mid
   70s south of the front with weak to moderate instability
   anticipated. Forcing will be somewhat nebulous given the rising
   heights aloft and weak convergence along the slow-moving, decaying
   front. 

   Nonetheless, moderate to potentially strong instability and an
   uncapped airmass should support some thunderstorms capable of severe
   wind gusts. Some lingering 30 to 40 knot mid-level flow is forecast
   to remain across portions of the warm sector Friday afternoon
   (particularly across northern Illinois/Indiana) which may aid in
   storm organization, but warm air aloft and a lack of clear supercell
   mode should limit the overall hail threat.

   ..Bentley.. 09/13/2026

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   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z