SPC AC 210655

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0155 AM CDT Thu Mar 21 2019

   Valid 231200Z - 241200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Scattered showers and thunderstorms are expected across the central
   and southern Plains and also across portions of Oregon, northern
   California, and northwestern Nevada on Saturday.  Any appreciable
   severe threat should remain low.

   ...Synopsis...
   The overall synoptic pattern should deamplify throughout the
   forecast period as a central U.S. trough weakens and lifts northward
   and a longwave trough across the East reaches the Atlantic.  Broad,
   quasi-zonal flow will become established across the Desert Southwest
   and southern Rockies, while a shortwave trough migrates
   northeastward across Oregon and northwestern Nevada.

   At the surface, a weak low/trough over western Kansas will move
   slowly eastward during the day, while a high initially centered over
   the Ohio River Valley shifts eastward toward the central
   Appalachians.  Between these two synoptic systems, a second day of
   moist advection will continue along an axis from south Texas to
   central Kansas, and a dryline will remain in place on the western
   edge of the moist airmass from southwestern Kansas
   south-southwestward toward the Big Bend area of Texas.  

   Showers and isolated thunderstorms ongoing at the beginning of the
   period from Kansas to north Texas should move northeastward toward
   the Missouri Ozarks and vicinity over the course of the forecast
   period, leaving a lull in precipitation in the afternoon across much
   of the southern Plains.  Along the dryline, surface heating and weak
   convergence may be enough for isolated convection to form late in
   the afternoon, although weak forcing for ascent, weak buoyancy, and
   capping should limit the extent of any development.  

   Lastly, lift associated with the northwestern U.S. shortwave and
   very cold -28 to -30C 500 hPa temperatures should support occasional
   lightning strikes in that area throughout the forecast period.

   ..Cook.. 03/21/2019

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