Mesoscale Discussion 0390
   NWS Storm Prediction Center Norman OK
   0312 PM CDT Thu Apr 18 2019

   Areas affected...Portions of western/central Alabama...Western
   Florida Panhandle

   Concerning...Severe potential...Tornado Watch likely 

   Valid 182012Z - 182215Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Storms will move into the discussion area late this
   afternoon and early evening. Observational and numerical model
   trends both suggest and increase in the potential for damaging winds
   and tornadoes. A tornado watch will likely be issued by 4 PM CDT.

   DISCUSSION...Afternoon boundary-layer mixing has reduced dewpoints
   across the discussion area by 1-3 F. Still, modifying the 18Z BMX
   sounding with surface observations across the region suggests that
   capping is eroding across southern Alabama and vicinity with
   destabilization perhaps a few more hours away in central Alabama.
   Latest surface analysis shows a deepening area of surface pressure
   in Louisiana into western Mississippi. With the continued approach
   of an upper-level trough, continued deepening of the surface low is
   anticipated through the overnight period. This mass response will
   increase theta-e advection into the western Florida Panhandle and
   Alabama helping to boost MLCAPE values 500-1500 J/kg by early
   evening.

   Observational trends in KDGX and KLIX VAD profiles have shown a
   large increase in low level hodograph curvature and SRH. These
   trends should continue as the trough shifts eastward. Guidance has
   suggested a marked increase in the low-level jet across much of
   Alabama during the 7-11 PM CDT time period. Given these expected
   favorable low-level shear parameters along with effective deep-layer
   shear of around 60 kts, organized convection with mid and low-level
   rotation appears likely. A tornado watch will be needed for this
   area. Aside from the tornado threat, strong winds fields will
   support a threat for damaging wind gusts as well.

   ..Wendt/Grams.. 04/18/2019

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

   ATTN...WFO...TAE...BMX...MOB...

   LAT...LON   33458820 33858751 33728641 33438590 31778575 30788608
               30278627 30168771 30188816 31658831 32638831 33458820