SPC AC 070731

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0231 AM CDT Tue Jul 07 2020

   Valid 091200Z - 101200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER
   MIDWEST INTO THE CENTRAL PLAINS AND OZARK PLATEAU...

   ...SUMMARY...
   Isolated severe thunderstorms are possible from the Upper Midwest
   into the Central Plains and Ozark Plateau on Thursday.

   ...Upper Midwest into the Central Plains/Ozarks...
   Location of the greatest severe weather potential on Thursday will
   depend largely on the organization and longevity of antecedent
   thunderstorms. Model guidance is in good agreement that an organized
   convective line will be in its dissipation stage over the Lower MO
   Valley early Thursday. Outflow boundary associated with this system
   will then serve as the primary location for convective development
   Thursday afternoon and evening. Based on current model progs, this
   initiation would occur from central KS eastward into southern MO.
   However, mesoscale nature of this scenario introduces significant
   uncertainty at this forecast range, resulting in the introduction of
   only 5% severe probabilities.

   The overall pattern, with a ridge building across the Southwest and
   a belt of enhanced upper flow from the Great Basin through the Mid
   MS Valley, suggests the potential exists for a convective line to
   initiate over the central High Plains and then move
   eastward/southeastward overnight. However, as with the threat
   discussed in the previous paragraph, predictability is limited by
   the numerous mesoscale factors involved in the development of such a
   convective line. This limited predictability is evidenced by the
   wide run-to-run and model-to-model variability in the development
   and location of the line. Given all of these factors, elected to
   include a broad 5% probability with the expectation increased
   probabilities will likely be needed in subsequent outlooks as the
   predictability improves.

   Lastly, a weak cold front is expected over the Upper Midwest,
   contributing to scattered thunderstorm development Thursday
   afternoon. Vertical shear will be weak but moderate to strong
   instability is still expected to result in a few stronger storms.

   ...Carolinas/VA Tidewater...
   A surface low is forecast to be just off the Carolina coast early
   Thursday morning. Showers and thunderstorms are expected across the
   Carolinas and into portions of southeast VA during the day.
   Strengthen/maturing of this low will result in enhanced low to
   mid-level flow throughout its eastern periphery. However, all the
   guidance currently keeps this region offshore, limiting the severe
   potential over land areas.

   ..Mosier.. 07/07/2020

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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