SPC AC 260719

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0219 AM CDT Tue May 26 2020

   Valid 281200Z - 291200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST
   TEXAS INTO DEEP SOUTH TEXAS AND FROM THE SOUTHEAST INTO THE MIDDLE
   OHIO VALLEY...

   ...SUMMARY...
   Isolated severe thunderstorms are possible from southwest Texas into
   deep south Texas Thursday afternoon through Thursday evening.
   Isolated severe storms are also possible across portions of the
   Tennessee and Middle Ohio Valleys.

   ...Southern Plains...
   Upper cyclone is forecast to be centered over the Ozark Plateau
   early Thursday. This cyclone is expected to move northeastward
   throughout the day, leaving northwesterly to westerly flow aloft
   over the southern Plains in its wake. Surface pattern is expected to
   feature a weak low over central OK with a front extending
   southwestward back into the TX Permian Basin. This boundary will
   likely surge southeastward throughout the day, interacting with the
   moist air mass downstream covering much of TX. Warm temperatures
   aloft may preclude widespread thunderstorm development but the
   environment will support for strong to severe storms with any
   initiation that does occur.  

   ...Southeast into the Middle OH Valley...
   Widespread showers and thunderstorms are expected from the
   lower/middle MS Valley eastward into the OH/TN Valleys as the upper
   cyclone initially over the Ozarks progresses northeastward. Enhanced
   low to mid-level flow throughout the eastern periphery of the upper
   cyclone will spread eastward/northeastward from the Southeast
   through the TN Valley into the middle OH Valley. This will result in
   enough vertical shear to support a few stronger, more organized
   updrafts capable of damaging wind gusts. Modest instability is
   currently expected to limit a more widespread or intense severe
   threat.

   ...Upper Midwest...
   A shortwave trough is expected to move from the Canadian Prairie
   Provinces through western Ontario and the Upper Midwest on Thursday.
   An associated surface low is forecast to move through western
   Ontario while an attendant cold front moves through the Upper
   Midwest. Guidance varies on the amount of destabilization that
   precedes the front across central/southern WI and adjacent portions
   of northwest IA and northern IL, but thunderstorms are probable.
   Weak vertical shear will limit overall severe potential but
   instability will likely be high enough to support a few stronger
   storms.

   ..Mosier.. 05/26/2020

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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