SPC AC 090721

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0221 AM CDT Fri Sep 09 2022

   Valid 111200Z - 121200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   A few stronger thunderstorms are possible across the Ohio Valley as
   well as the Lower Colorado River Valley from Sunday afternoon into
   early Monday morning. Severe thunderstorm potential is low.

   ...Synopsis...
   Upper troughing is forecast to extend along the MS Valley early
   Sunday morning. This troughing is expected to be flanked by upper
   ridging, one centered off the Southeast coast and the other
   extending from northern Mexico into the Great Basin. A shortwave
   trough will likely be embedded within the large upper troughing,
   extending from the Upper MS Valley southwestward into the central
   Plains early in the period. This shortwave is then expected to
   progress eastward while maturing, evolving into a closed upper low
   centered over northern IL by early Monday morning.

   The remnants of Tropical Storm Kay will likely be centered off the
   southern CA coast, contributing to increased low- and mid-level
   moisture across the Southwest. Isolated to scattered thunderstorms
   are anticipated across the region, with the highest coverage across
   AZ. 

   ...Mid MS Valley into the Middle OH Valley... 
   Moderate mid-level flow will accompany the maturing shortwave
   mentioned in the synopsis, spreading across the Mid MS Valley during
   the afternoon and evening. An associated surface low and attendant
   cold front are expected to move from IL to OH. A moist air mass will
   be in place ahead of this front, but buoyancy will remain modest
   given the poor mid-level lapse rates in place. Even so, enough
   buoyancy should be in place for thunderstorms along and ahead of the
   front. However, the stronger mid-level flow should lag behind the
   front, displaced west of any storms. The modest buoyancy and shear
   should limit storm severity.

   ...Lower CO River Valley and vicinity...
   Some enhancement of the low- to mid-level flow is possible between
   the remnants of Kay and the upper ridging to its east, particularly
   if the remnants drift eastward throughout the day. This enhancement
   would support stronger shear and an increased potential for a few
   stronger storms. However, this strengthening of the low- to
   mid-level flow is most likely overnight and into early Monday. As a
   result, low-level nocturnal stabilization should temper the overall
   severe potential.

   ..Mosier.. 09/09/2022

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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