Mesoscale Discussion 0040
   NWS Storm Prediction Center Norman OK
   0115 PM CST Sat Jan 11 2020

   Areas affected...Portions of central into northeastern AL

   Concerning...Tornado Watch 13...15...

   Valid 111915Z - 112045Z

   The severe weather threat for Tornado Watch 13, 15 continues.

   SUMMARY...Damaging straight-line wind and isolated tornado potential
   should be maximized across parts of central into northeastern AL
   over the next couple of hours.

   DISCUSSION...A mature squall line that has a history of producing
   damaging straight-line winds and embedded tornadoes is moving
   east-northeastward around 40-50 kt across central into northeastern
   AL. Although diurnal heating has been stunted by widespread cloud
   cover, surface temperatures have warmed into the low to mid 70s
   across this area, with surface dewpoints generally in the low to mid
   60s. An 18Z special sounding from KBMX just ahead of the line shows
   the temperature inversion around 700 mb has almost completely
   eroded, with about 340 J/kg of MLCAPE present. The observed wind
   profile also shows very favorable low to mid-level shear that will
   help maintain storm organization for at least the next couple of
   hours. Effective SRH around 450-600 m2/s2 will likely foster
   continued low-level circulations embedded within the line, with
   isolated tornado potential. Otherwise, straight-line winds of 50-70
   mph along the length of the squall line will continue to produce
   damage through the afternoon. Portions of the line that are oriented
   more orthogonal to the southwesterly mid-level flow will likely have
   the greatest strong to severe wind potential (such as the bowing
   segment moving from Jefferson, St. Clair, and Blount counties into
   northeastern AL).

   ..Gleason.. 01/11/2020

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

   ATTN...WFO...BMX...HUN...

   LAT...LON   33928675 34478679 34758669 34908635 34918593 34768563
               34008545 33518574 32728661 32738701 33618670 33928675