Mesoscale Discussion 0267
   NWS Storm Prediction Center Norman OK
   0150 AM CDT Sun Mar 29 2020

   Areas affected...Northern AL...Middle TN...Far South-Central KY

   Concerning...Tornado Watch 74...75...

   Valid 290650Z - 290815Z

   The severe weather threat for Tornado Watch 74, 75 continues.

   SUMMARY...The threat for all severe hazards, include brief
   tornadoes, will continue across middle TN and northern AL for the
   next few hours. Less favorable downstream environment is expected to
   preclude new watch issuance but short-lived, local watch extensions
   may needed.

   DISCUSSION...Radar imagery of the ongoing cluster of storms over the
   southern portion of middle TN has shown an increase in forward speed
   over the past half hour or so. Echo tops have also increased during
   this time. These observations suggest a continued threat for severe
   will likely exist downstream of these storms for at least the next
   hour or so. Primary threat with this cluster is strong wind gusts,
   although an brief embedded tornado and/or hail also remain possible.
   Storm motion of this cluster was estimated to be northeast at 60 kt,
   taking it to the edge of Tornado Watch 74 around 0730Z. 

   This fast northeastward motion will take the cluster ahead of the
   ongoing moisture return into a thermodynamic environment
   characterized by strong MLCIN, which should lead to a diminishing of
   storm intensity. Isolated damaging wind gusts will still be possible
   and short-lived, local watch extensions may needed. However, the
   limited spatial and temporal severe threat will likely preclude new
   watch issuance downstream. 

   A few stronger cells have also been noted within the line over
   northwest AL. Estimated storm motion within these cells is
   northeastward at 50 kt, taking them to the central AL/TN border
   around 0700Z. Recent UAH SWIRLL soundings from Courtland AL and
   Huntsville AL both show a warm layer around 700 mb, which is likely
   leading to reduced updraft strength. Even so, the strong vertical
   shear will likely compensate for this reduced instability, leading
   to a continued severe threat for the next few hours.

   ..Mosier.. 03/29/2020

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

   ATTN...WFO...MRX...JKL...FFC...LMK...OHX...HUN...

   LAT...LON   35858663 36468598 36878469 36358421 35548438 34678560
               34478766 35858663