Mesoscale Discussion 0613
   NWS Storm Prediction Center Norman OK
   0116 PM CDT Sat May 16 2020

   Areas affected...Portions of northern LA...southern/central
   AR...northeast TX...and far southeastern OK

   Concerning...Severe potential...Watch possible 

   Valid 161816Z - 162045Z

   Probability of Watch Issuance...40 percent

   SUMMARY...The potential for low-topped storms capable of producing
   isolated, generally brief tornadoes and strong/gusty straight-line
   winds may increase this afternoon. Watch issuance is possible.

   DISCUSSION...A well-defined MCV evident on both radar and visible
   satellite imagery is located over east TX at 1815Z. A convcetively
   enhanced mid-level trough is also centered over north TX early this
   afternoon. Modest diurnal heating to the east of both these features
   is occurring across the ArkLaTex region, with temperatures warming
   into the mid/upper 70s and low 80s. Rich low-level moisture combined
   with this heating will maintain 500-1000 J/kg of MLCAPE over this
   region through the afternoon. Both the MCV and mid-level trough are
   forecast to develop slowly east-northeastward across northeast TX. A
   30-40 kt south-southeasterly low-level jet will also persist over
   northern LA into southern/central AR and vicinity. Recent VWPs from
   KSHV show a strengthening/veering wind profile in the 0-3 km layer
   associated with this low-level jet. Per latest mesoanalysis
   estimates, 0-1 km shear has increased to 20-25 kt, with effective
   SRH around 100-200 m2/s2. This low-level shear should be sufficient
   for updraft rotation with any low-topped storms that can form and
   persist across the warm sector east/northeast of the MCV. Isolated
   tornadoes appear possible, but they should remain generally brief if
   they occur owing to marginal deep-layer shear needed for sustained
   supercells. Some strong/gusty straight-line winds may also occur if
   storms can form into loosely organized clusters. Watch issuance
   appears possible this afternoon, but will be highly dependent on
   convective trends/intensity.

   ..Gleason/Dial.. 05/16/2020

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

   ATTN...WFO...JAN...LZK...SHV...TSA...

   LAT...LON   33089527 33999518 34569476 34859382 34779275 34349194
               33219154 32209175 31849234 31939371 32739501 33089527