SPC AC 180815

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0215 AM CST Sun Feb 18 2018

   Valid 201200Z - 211200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Thunderstorms are forecast to occur from the southern Plains
   northeast to the Great Lakes.  Showers -- and possibly a couple of
   lightning strikes -- may also occur over the Four Corners vicinity.

   ...Synopsis...
   A highly amplified flow field aloft will remain over the U.S. this
   period.  Long-wave troughing will remain established over the
   western half to two-thirds of the country, as one embedded
   short-wave trough ejects northeast across the Plains but a second
   digs southward across the northwestern states toward the Great Basin
   -- thus resulting in quasi-stationary persistence of the long-wave
   feature.

   At the surface, cold polar air will continue spreading east and
   southeast across western and central portions of the country.  A
   cold front at the leading edge of the cold surge will move east
   across the Great Lakes/Midwest, and southeast across the Ozarks and
   southern Plains through the period.

   While showers -- and possibly a few lightning strikes -- are
   expected over the Four Corners area, greater thunderstorm coverage
   will remain associated with the advancing cold front, within a zone
   from the southern Plains to the Great Lakes.

   ...Texas...
   Showers and elevated thunderstorms are expected across much of
   central and eastern Texas during the period.  Some convection may be
   ongoing early in the period, with more widespread precipitation
   spreading southeast with time as the front advances.  At this time,
   it appears that thunderstorms associated with the advance of the
   front across Texas during the second half of the period will be
   largely -- if not almost entirely -- confined to the cool side of
   the front.  Confluent flow aloft, and a lack of mid-level height
   falls, suggest that large-scale ascent should remain modest at best
   through the deeper troposphere atop the warm sector.  As such,
   generally weak convection in an anafrontal-type regime is currently
   expected, which should hinder appreciable severe risk.

   ..Goss.. 02/18/2018

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