SPC AC 140729

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0229 AM CDT Tue Jul 14 2020

   Valid 161200Z - 171200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OZARKS
   NORTHEAST TO THE OHIO VALLEY AND WESTERN NEW YORK...AS WELL AS
   ACROSS THE CENTRAL HIGH PLAINS...

   ...SUMMARY...
   Strong to isolated severe storms are possible on Thursday from the
   Ozarks into the Ohio Valley and western New York. Additional strong
   storms are possible over the central High Plains.

   ...Ozarks into the Ohio Valley and Western New York...

   A series of shortwave impulses will migrate through an upper trough
   pivoting east/northeast across the Great Lakes on Thursday. This
   will result in areas of enhanced west/southwesterly flow streaming
   over the region. At the surface, a very moist and unstable air mass
   will be in place, with dewpoints in the mid 60s to low 70s F
   expected ahead of an east/southeastward progressing cold front
   across the Midwest. This is likely to be one or more MCVs migrating
   across the area as well, associated with expected MCSs in the Day 1
   and Day 2 period. Uncertainty in the location of the surface
   boundary and any mesoscale features will preclude higher severe
   probabilities at this time, but at least isolated severe storms
   appear possible. High PWs and modest vertical shear amid moderate to
   strong instability should favor mainly a locally damaging wind
   threat Thursday afternoon into Thursday evening.

   ...Central High Plains...

   Southeasterly low level flow will bring upper 50s to mid 60s F
   dewpoints northwestward into eastern CO/western NE. A surface trough
   will extend southward through the northern/central High Plains.
   West/northwest mid/upper flow will increase through the period as an
   upper trough spreads across the Pacific Northwest and Northern
   Rockies, shunting the western upper ridge eastward over the Plains
   by Friday morning. Northwesterly flow aloft atop southeasterly low
   level flow will result in moderate effective shear. High-based
   supercells are possible by late afternoon as a weak shortwave
   impulse ejects eastward ahead of the main upper trough. Isolated
   strong/severe storms capable of strong gusts and perhaps hail will
   be possible through the evening.

   ..Leitman.. 07/14/2020

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