SPC AC 080722

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0222 AM CDT Wed Jul 08 2020

   Valid 101200Z - 111200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER
   WESTERN/CENTRAL SOUTH DAKOTA AND NORTH-CENTRAL/NORTHEAST NEBRASKA...

   ...SUMMARY...
   Severe thunderstorms are expected across portions of the northern
   and central Plains Friday. Greatest severe weather risk is currently
   forecast over from western South Dakota into central Nebraska Friday
   evening/night.

   ...Synopsis...
   Upper ridging is forecast to remain centered over the Southwest on
   Friday, with some northward/eastward expansion anticipated. Belt of
   enhanced westerly flow aloft will persist north of this upper ridge,
   extending from northern CA/Pacific Northwest into the Mid/Upper MS
   Valley. Model guidance is good agreement that a low-amplitude
   shortwave trough will move eastward within this belt of stronger
   flow aloft, reaching the northern High Plains by Friday afternoon
   and the Upper Midwest by early Saturday morning. 

   ...Great Plains...
   A decaying convective line will likely be moving into the Ozark
   Plateau early Friday morning. Some severe risk is possible
   downstream as this line continues southeastward. However, 
   uncertainties regarding the strength and location of the line as
   well as the downstream environment limits predictability, precluding
   the introduction of any severe probabilities in this area. 

   Farther north, low-level moisture return into the northern and
   central High Plains will contribute to a moderately to strongly
   unstable environment ahead of the approaching shortwave trough.
   Initially discrete thunderstorms are expected to develop along the
   lee trough. Long, straight hodographs suggest splitting supercells
   capable of large hail (isolated very large) and strong wind gusts
   are possible. Eventual upscale growth into an organized convective
   line appear probable, with a risk for strong wind gusts then
   continuing downstream. Given the uncertainties at this forecast
   range, elected to introduce only 15% probabilities. However, higher
   severe probabilities may be needed in later outlooks if a corridor
   of greater severe potential becomes apparent.

   ..Mosier.. 07/08/2020

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