Storm Prediction Center Mesoscale Discussion 856

   Mesoscale Discussion 0856
   NWS Storm Prediction Center Norman OK
   0954 AM CDT Sun May 18 2025

   Areas affected...parts of northern Mississippi into much of central
   Alabama

   Concerning...Severe potential...Watch possible 

   Valid 181454Z - 181730Z

   Probability of Watch Issuance...60 percent

   SUMMARY...An isolated severe risk over northern Mississippi may
   increase in coverage and spread into northern and central Alabama by
   early afternoon. Damaging winds would be the main risk.

   DISCUSSION...A small MCS is currently moving across northern MS,
   with periodic strengthening. Outflow extends southwestward from this
   system toward the AR/LA border, with only shallow showers there.

   A moist and unstable air mass exist along and south of the current 
   MCS/cell track. Southwest low-level winds will aid advection out of
   the southwest during the day as heating occurs, though speeds will
   not be very strong and as such the instability gradient may not move
   much. However, strong westerlies aloft are evident on the 12Z
   soundings, and midlevel lapse rates will support strong/uncapped
   instability with minimal heating. As such, an increasing severe
   storm threat is expected from MS into AL, and a watch may eventually
   be needed.

   ..Jewell/Hart.. 05/18/2025

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

   ATTN...WFO...BMX...HUN...MEG...JAN...

   LAT...LON   33998974 34148958 33918671 33458630 32808618 32188657
               32438849 33068994 33519023 33998974 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN