Current Mesoscale Discussions

Mesoscale Discussion 0315

   NWS Storm Prediction Center Norman OK
   0450 AM CDT Sat Apr 13 2019

   Areas affected...portions of west-central Texas southward toward the
   Rio Grande

   Concerning...Tornado Watch 49...

   Valid 130950Z - 131045Z

   The severe weather threat for Tornado Watch 49 continues.

   SUMMARY...The severe threat continues across WW 49.

   DISCUSSION...Convection has generally struggled to deepen across the
   WW area this morning, although one cell recently crossed the Rio
   Grande near DFX.  This storm is surviving despite weak inhibition,
   and has a threat of all modes of severe as long as it can persist.

   Uncertainty persists with regard to the extent of convection across
   the region. However, it appears that severe convection will remain
   possible through the entirety of the valid WW period as the region
   remains under the grazing influence of ascent from a mid-level wave
   over New Mexico/northern Mexico.  It is also possible that
   convection moving eastward from Terrell County may interact
   favorably with the warm frontal zone near that region and pose a
   severe threat as well.  PFCs/profiles remain supportive of organized
   convection favoring all modes of severe - thus the severe threat
   across WW 49 continues.

   ..Cook.. 04/13/201Mesoscale Discussion 0314

   NWS Storm Prediction Center Norman OK
   0435 AM CDT Sat Apr 13 2019

   Areas affected...west-central into north-central Texas

   Concerning...Severe Thunderstorm Watch 48...

   Valid 130935Z - 131030Z

   The severe weather threat for Severe Thunderstorm Watch 48
   continues.

   SUMMARY...The severe threat continues across WW 48 downstream of a
   complex of storms between San Angelo and Midland, TX.  Additional
   elevated convection may also pose a hail threat this morning.

   DISCUSSION...The severe threat continues across WW 48.  Convection
   has congealed into a mix of linear and cellular modes in west Texas,
   with one lone supercell continuing to exhibit occasionally strong
   velocity signatures and indications of 1-2" diameter hail potential
   in Irion County.  There storms are slightly elevated and just north
   of the warm frontal zone, which is probably mitigating any tornado
   threat.  Downstream of this activity, convection continues to deepen
   within a steep-lapse-rate environment, with effective shear
   supporting organization and updraft rotation.  These storms could
   also produce occasional 1" hailstones at times as they mature.

   Over time, high-resolution guidance suggests that the current linear
   complex and cells out ahead will continue to migrate east-northeast,
   with hail being the primary severe risk.  A new WW may be needed
   downstream of the current one pending 1) severity of the ongoing MCS
   and cells out ahead and 2) northward progress of the warm front on
   the southern periphery of the watch, which may increase the
   tornado/damaging-wind threat with storms that can become surface
   based.  A new MD will probably be issued to update on downstream
   watch potential later this morning.

   ..Cook.. 04/13/2019