Mesoscale Discussion 0016
   NWS Storm Prediction Center Norman OK
   0252 PM CST Fri Jan 10 2020

   Areas affected...Portions of central into south-central TX

   Concerning...Severe potential...Watch likely 

   Valid 102052Z - 102245Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe threat is increasing this afternoon. Scattered
   large hail and perhaps isolated giant hail will be possible, along
   with strong/damaging winds. A tornado or two may also occur. Watch
   issuance is likely in the next hour or so (by 22Z / 4 PM CST).

   DISCUSSION...Strong surface pressure falls around 2.5-3.5 mb in the
   past two hours are occurring across parts of central TX this
   afternoon. This is indicative of large-scale ascent associated with
   a strong mid/upper-level jet overspreading this region. Storms will
   likely erupt along a pre-frontal confluence zone in the next couple
   of hours as this pronounced ascent erodes a low-level cap. As this
   convection moves eastward over parts of central TX and vicinity
   through the remainder of the afternoon and this evening, it will
   encounter a moderately to strongly unstable airmass. MLCAPE of
   1500-2500 J/kg will likely persist as steep mid-level lapse rates
   overlie surface dewpoints generally in the lower to mid 60s F. RAP
   forecast soundings and recent VWPs from KGRK/KEWX show rapid
   strengthening of the low/mid-level winds, along with some veering.
   This is supporting 50-60 kt of effective bulk shear, which will be
   more than sufficient for supercells.

   Scattered large hail should be the primary severe threat with
   initial semi-discrete development. Some of this hail could become
   very large (2+ inches in diameter) given the degree of instability
   and shear present. Strong to damaging winds may become an increasing
   concern later this evening as storms eventually congeal into a
   cluster/line along an eastward-moving cold front. A tornado or two
   also appears possible, mainly with the initial supercells, although
   a strong low-level jet and related shear will tend to shift slowly
   northeastward and away from central TX through the evening. Watch
   issuance will likely be needed within the next hour or so as storm
   initiation becomes increasingly probable.

   ..Gleason/Hart.. 01/10/2020

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

   ATTN...WFO...CRP...EWX...

   LAT...LON   28829959 29139979 29679976 30119942 30489893 30909838
               30879784 30639739 30309701 29869687 29289698 28879733
               28599786 28559843 28599896 28829959