SPC AC 230826

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0226 AM CST Mon Nov 23 2020

   Valid 251200Z - 261200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE LOWER/MID MISSISSIPPI VALLEY...TENNESSEE VALLEY...AND
   SOUTHEAST...

   ...SUMMARY...
   Isolated strong to severe thunderstorms may occur Wednesday across
   parts of the lower/mid Mississippi Valley into the Tennessee Valley
   and Southeast.

   ...Lower/Mid Mississippi Valley into the Tennessee Valley and
   Southeast...
   A closed upper low with associated southwesterly mid-level jet
   should continue to advance from the lower/mid MS Valley to the
   Mid-Atlantic vicinity on Wednesday. A surface low initially over
   northern MO is forecast to develop northeastward across the
   Midwest/OH Valley and lower Great Lakes while slowly filling through
   the period. A cold front extending southward from this low should
   progress generally eastward across parts of the lower/mid MS Valley,
   TN Valley, and Southeast through the day.

   A broken line of showers/storms may be ongoing at the start of the
   period across these regions along/ahead of the cold front with a
   isolated/marginal severe threat. Substantial low-level moisture
   return will probably make only a limited northward advance ahead of
   the front. Still, diurnal heating and cooling mid-level temperatures
   with the approach of the upper trough/low may promote weak
   instability through Wednesday evening across the narrow warm sector.
   Given strong flow aloft attendant to the previously mentioned
   mid-level jet, there should be more than enough deep-layer shear to
   support organized storms. Isolated strong to damaging winds appear
   to be the main threat with any storms that can either persist along
   the front or develop ahead of it. A brief tornado or two also cannot
   be ruled out mainly early in the period, before low-level winds veer
   more west-southwesterly as the primary low-level jet shifts north of
   the surface warm sector and into the OH Valley by Wednesday evening.
   Eventually, the cold front should outpace the modest low-level
   moisture return across the TN Valley and Southeast, with a gradual
   reduction in the already isolated/marginal severe threat by late
   Wednesday evening as the system occludes.

   ..Gleason.. 11/23/2020

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z