ZCZC SPCSWOMCD ALL ACUS11 KWNS 181825 SPC MCD 181825 TXZ000-NMZ000-182100- Mesoscale Discussion 1117 NWS Storm Prediction Center Norman OK 0125 PM CDT Tue Jun 18 2019 Areas affected...eastern New Mexico and far West Texas into the Transpecos/South Plains Concerning...Severe potential...Watch possible Valid 181825Z - 182100Z Probability of Watch Issuance...40 percent SUMMARY...Isolated storms may develop over the next 1-2 hours, with more widespread development expected later. While eventual WW issuance may be needed eastward across western and central Texas, need for a watch in the shorter term, westward into far West Texas and eastern New Mexico, remains uncertain. DISCUSSION...Latest visible satellite imagery shows some deeper cumulus increasing over the higher terrain of central/south-central New Mexico, and southward across portions of the Davis Mountains. This convection is on the western fringe of the instability gradient, and is evolving in line with various CAM runs which show isolated storm initiation in the 19Z to 20Z time frame across this region. Weak short-wave ridging -- and associated weak subsidence -- is expected to maintain a largely capped boundary layer, such that development should remain initially isolated. With that said, steep lapse rates aloft/moderate CAPE combined with enough veering and increase of the flow with height to yield modest shear, would support severe potential with any sustained storm. Still, current expectations are that any storms development over the next couple of hours within the discussion area should remain isolated enough so as to preclude the need for WW issuance. We will continue to monitor cumulus/convective development across this region, for any signs that coverage could become greater in the short term than is currently anticipated. Late this afternoon into early evening, as convection progresses eastward across the South Plains/Transpecos region, increased development/upscale growth -- in conjunction with initial low-level jet development -- will result in more widespread potential for severe weather, and attendant need for WW issuance. ..Goss/Guyer.. 06/18/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EWX...SJT...LUB...AMA...MAF...ABQ...EPZ... LAT...LON 30410478 33360511 34500518 35170372 34780215 32090162 30580095 29860165 29770267 28920322 29560444 30410478 NNNN