SPC AC 050558

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1258 AM CDT Sun May 05 2019

   Valid 051200Z - 061200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS
   INTO THE MIDDLE MISSOURI VALLEY...AND OVER PARTS OF THE MID
   ATLANTIC...

   ...SUMMARY...
   Scattered severe storms capable of hail and wind are possible from
   west Texas into eastern Nebraska and southwest Iowa, and across
   parts of the Mid Atlantic.

   ...Synopsis...
   A broad zone of 40-60 kt midlevel cyclonic flow aloft will remain
   over the northern Plains as an upper low ejects northeast out of
   Ontario. Meanwhile, a cold front will sink southward to a WI to
   central NE line by late afternoon, providing convergence while 50s F
   dewpoints aid instability. 

   To the east, a low-amplitude shortwave trough will move across the
   Mid Atlantic region during the day, with 40-50 kt midlevel
   westerlies. Low pressure will move from western NC across southeast
   VA, enhancing lift before exiting the coast by evening. Dewpoints in
   the 60s F will exist near the low track, and southward across the
   Carolinas as surface winds veer.

   To the west, southerly winds across the Plains will maintain low 60s
   F dewpoints over much of TX, with a dryline just east of the NM/TX
   border by late afternoon. Height rises will occur throughout the
   period, but strong heating will likely result in storms.

   ...Southeast VA into northeast NC...
   Areas of showers or weak thunderstorms are possible in a weak warm
   advection regime early in the day, with southwesterly 850 mb winds
   around 35 kt. In the wake of this activity, heating will occur, and
   lift will increase as the low develops northeastward toward
   southeast VA. Lapse rates aloft will be poor, but enhanced shear and
   lift along the low track may favor a small corridor of severe wind
   or even a brief tornado. Other marginal hail or wind will be
   possible in the warm sector across the remainder of the Carolinas.

   ...Southeast NE into western IA...
   Heating will occur ahead of the cold front, resulting in steep lapse
   rates.  MUCAPE in excess of 2000 J/kg is forecast by peak heating,
   which will likely support a small MCS along the cold front. Initial
   development may contain hail, with an increasing wind threat with
   any linear structures that develop south toward the KS border during
   the evening. Marginally severe hail is possible as far northeast as
   IA, and perhaps southern WI if instability is greater than currently
   forecast.

   ...Much of west Texas...
   Strong heating along the dryline will fully erode CIN by late
   afternoon, with scattered strong to severe storms likely despite
   weak low-level convergence. Modest westerly flow aloft combined with
   weakly veering winds with height will support slow-moving cells or
   clusters, capable of severe hail and/or wind. Various model
   solutions suggest the greatest concentration of storms will be from
   the South Plains toward the Big Bend. Other widely scattered severe
   storms are possible farther north across the TX Panhandle and
   western KS.

   ...FL...
   A moist and unstable air mass with MUCAPE averaging around 2500 J/kg
   will develop over much of the Peninsula, with modest westerlies
   aloft related to the shortwave trough to the north. By late
   afternoon, weakly veering winds with height may support cellular
   activity capable of marginal hail or wind, most likely from the
   central Peninsula toward the east Coast. CAMS suggest some of the
   cells may propagate southeastward along the sea-breeze from Palm
   Beach into Broward counties.

   ..Jewell/Bentley.. 05/05/2019

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