SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Mon Mar 11 2019 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Severe thunderstorms capable of producing isolated damaging winds, large hail, and perhaps a tornado or two will be possible beginning mainly late Tuesday afternoon and continuing through the overnight hours across parts of the southern Plains. ...Synopsis... A closed upper low over the lower CO River Valley and adjacent Baja Peninsula will evolve into a negatively tilted shortwave trough as it ejects east-northeastward across the Southwest and southern Plains on Tuesday. Strong ascent preceding this shortwave trough will encourage surface cyclogenesis across the southern/central High Plains through the day, with a deep surface low eventually consolidating over southeastern CO. Low-level mass response will bring at least partially modified Gulf moisture westward and northward across the southern Plains. ...Southern Plains... Isolated to perhaps widely scattered elevated thunderstorms posing a marginal hail threat may be ongoing Tuesday morning across parts of eastern NM into west TX in a low-level warm air advection regime. This convection should spread northeastward across the TX/OK Panhandles and main body of OK through the afternoon. At least some diurnal heating should occur across the higher terrain of central/eastern NM into west TX in the wake of this morning activity. This heating combined with steep mid-level lapse rates emanating from the higher terrain of northern Mexico and surface dewpoints in the mid 50s to lower 60s should foster MLCAPE of 500-1000 J/kg across the southern High Plains through peak diurnal heating. Convective initiation appears likely by late Tuesday afternoon as a strong southwesterly mid-level jet attendant to the shortwave trough overspreads eastern NM and west TX. Effective bulk shear exceeding 50 kt will easily support supercells with mainly an isolated large hail threat. A Pacific cold front will eventually overtake this convection Tuesday evening, with upscale growth into squall line likely. Isolated damaging winds should be the primary threat with this linear convection as it moves quickly eastward across central/east TX overnight. A tornado or two also cannot be ruled out within the line due to the strong low-level shear that will be present owing to a 45-60+ kt southerly low-level jet. Eventually this squall line should weaken some as it encounters a less unstable airmass across east TX late in the period. There is still considerable uncertainty whether there will be sufficient low-level moisture return across western/central OK to support surface-based thunderstorms. Have therefore refrained from making any substantial changes to the Marginal and Slight risk delineations across this area. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 15% - Slight Hail: 15% - Slight ..Gleason.. 03/11/2019
from SPC Convective Outlooks http://bit.ly/1LHQZVW
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