SPC AC 230732

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0132 AM CST Thu Dec 23 2021

   Valid 251200Z - 261200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Isolated thunderstorms will be possible along the Pacific Coast and
   in portions of the Ohio Valley on Saturday.

   ...Synopsis...
   An amplifying mid-level trough will move onshore on the West Coast
   on Saturday. Farther east, a mid-level trough will weaken as it
   moves through the Ohio Valley with mid-level ridging building across
   the central Plains.

   ...West Coast...
   A reinforcing shot of cold air aloft will arrive as the upper-level
   trough approaches. This colder air aloft, with relatively warm ocean
   waters at the surface, will provide enough instability for some
   isolated lightning with cellular activity over the water. While most
   activity should remain near the coast, some isolated lightning
   strikes may make it farther inland in the central California Valley.

   ...Ohio Valley...
   A weak mid-level trough will deamplify as it moves from the Midwest
   to the Ohio Valley during the day. While the upper-level feature
   will not be that apparent, the frontal circulation is expected to
   strengthen through the day which will lead to an increasing
   precipitation shield along and to the north of the front. Low-level
   moisture advection is expected to feed mid 50s dewpoints northward
   to near the front. This moisture is expected to be quite deep with
   850mb dewpoints in excess of 8C. Any instability in the region will
   likely be quite weak, but enough may exist for a few lightning
   flashes near the front.

   ..Bentley.. 12/23/2021

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