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Mesoscale Discussion 801
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MD 801 graphic

   Mesoscale Discussion 0801
   NWS Storm Prediction Center Norman OK
   0212 PM CDT Sat May 20 2017

   Areas affected...Portions of LA...much of MS...and western/central

   Concerning...Severe potential...Watch unlikely 

   Valid 201912Z - 202045Z

   Probability of Watch Issuance...20 percent

   SUMMARY...An isolated strong/gusty wind threat will persist through
   the remainder of the afternoon. Watch issuance is unlikely.

   DISCUSSION...Latest visible satellite imagery shows an outflow
   boundary moving southeastward across western MS, and multiple
   clusters of convection have developed across eastern MS and
   western/central AL in a low-level warm air advection regime. Outflow
   from thunderstorms across eastern MS is moving westward, and
   additional convection along these converging outflow boundaries will
   likely occur over the next several hours across much of central MS.
   A moist low-level airmass and diurnal heating have resulted in
   MLCAPE generally ranging from 1500-2500 J/kg across the discussion
   area, even though mid-level lapse rates remain modest (5.5-6.5 C/km
   in the 700-500 mb layer).

   With the primary upper trough/low located across the central Plains
   and far to the northwest, large-scale forcing for ascent and
   stronger mid-level winds will be mostly displaced to north of this
   region. Still, some veering of winds with height present on recent
   DGX/GWX VWPs are supporting around 30 kt of effective bulk shear,
   and isolated instances of strong to locally damaging winds may occur
   with the strongest cores through the remainder of the afternoon.
   Current expectations are for thunderstorms to remain mostly
   disorganized, and the overall severe weather threat will likely
   remain too isolated/marginal to warrant watch issuance.

   ..Gleason/Weiss.. 05/20/2017

   ...Please see for graphic product...


   LAT...LON   34958817 34948740 34898664 33218655 32568696 31528792
               30698973 30379075 30359116 30859206 32519135 33389036
               34208985 34888874 34958817 

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