Mesoscale Discussion 2085
   NWS Storm Prediction Center Norman OK
   1034 AM CST Thu Dec 30 2021

   Areas affected...portions of western Alabama into central Georgia

   Concerning...Severe potential...Watch possible 

   Valid 301634Z - 301830Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A gradual uptick in severe potential is possible into the
   early afternoon hours. Damaging gusts would be the primary severe
   threat, though a tornado or two is also possible. A WW issuance may
   eventually be needed over the next couple of hours.

   DISCUSSION...Multiple discrete/semi-discrete west-east progressing
   storms have been moving roughly parallel to a southward-sagging
   surface cold front over the past couple of hours. In the past hour,
   some of these storms have deviated to the right slightly, with KBMX
   and MRMS mosaic radar showing modest low and mid-level rotation with
   storms in central AL. Surface temperatures ahead of these storms are
   at least in the mid 70s F, with near 70 F dewpoints, contributing to
   1000 J/kg MLCAPE given 6-6.5 C/km mid-level lapse rates (per 16Z
   mesoanalysis). Though parallel to the surface cold front, 50 kts of
   effective bulk shear suggests that potential exists for the more
   intense, sustained updrafts to become or remain organized.  

   While overall deep-layer ascent is weak, ample diurnal heating ahead
   of these storms may foster enough lift and buoyancy to pose a severe
   threat. Given veered low-level wind profiles (evident via recent MXX
   and JGX VWPs), damaging gusts are anticipated to be the primary
   threat, though a tornado also cannot be ruled out given nearly 150
   m2/s2 0-1 km SRH. The main question is when the bulk of the severe
   threat will occur. A sparse severe threat exists at present.
   However, since the uptick in severe may be gradual, a WW may not be
   needed for at least a few more hours. Convective trends will
   continue to be monitored for the need of a WW issuance.

   ..Squitieri/Goss/Hart.. 12/30/2021

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

   ATTN...WFO...CAE...FFC...BMX...MOB...

   LAT...LON   32348836 33118602 33458405 33538258 33468252 33078234
               32768234 32428243 32388258 32188317 32108368 31948609
               32038744 32058816 32348836