Mesoscale Discussion 1548
   NWS Storm Prediction Center Norman OK
   0344 PM CDT Sat Jul 20 2019

   Areas affected...Portions of central and southern Lower Michigan

   Concerning...Severe Thunderstorm Watch 531...

   Valid 202044Z - 202245Z

   The severe weather threat for Severe Thunderstorm Watch 531
   continues.

   SUMMARY...Threat for isolated strong/damaging wind gusts will
   continue in WW 531. Greatest likelihood for these gusts will be in
   east-central Lower Michigan. Another round of convection may move
   through later this evening, but a thoroughly overturned airmass
   ahead of it leads to uncertainty with regard to how severe the
   secondary line will be.

   DISCUSSION...An ongoing line of convection continues to move
   southeastward into central and southern Lower Michigan. This line
   has become less organized in the last few hours with velocities
   behind the leading convection trending downward as well as outflow
   moving ahead of the convection per KGRR radar imagery. Ahead of this
   activity, upper 70s dewpoints have advected into a narrow corridor
   of southwestern/south-central Michigan. Here, 2500-3500 MLCAPE may
   support a few isolated strong updrafts with potential for damaging
   wind gusts. Farther north, in east-central Michigan, the convective
   line has shown better intensity on radar. A small area of
   east-central Michigan still contains modestly buoyant air (1000-2000
   J/kg MLCAPE) and slightly higher deep layer shear (25-35 kts) where
   isolated damaging wind gusts will remain possible.

   A convective line now moving east through southern Wisconsin will
   likely move into southern Lower Michigan later this evening.
   However, given the amount of convective overturning that has
   occurred in that region, the intensity of this line in a few hours
   is highly in question. Should it encounter undisturbed warm sector
   air, most likely along the southern Michigan border, strong/damaging
   wind gusts would be possible.

   ..Wendt.. 07/20/2019

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...DTX...APX...IWX...GRR...

   LAT...LON   42268640 42568631 42928574 43308525 43868481 44348429
               44368344 44018253 43208239 42308315 41868380 41878629
               41948653 42268640