ZCZC SPCSWOMCD ALL ACUS11 KWNS 122010 SPC MCD 122010 TXZ000-NMZ000-122215- Mesoscale Discussion 0180 NWS Storm Prediction Center Norman OK 0310 PM CDT Tue Mar 12 2019 Areas affected...Southeast New Mexico into portions of West Texas Concerning...Severe potential...Tornado Watch likely Valid 122010Z - 122215Z Probability of Watch Issuance...80 percent SUMMARY...Isolated supercell development is possible in the next 1 to 2 hours. Any storms which develop will pose a threat for tornadoes and very large hail. DISCUSSION...Thick cloud cover and fog which has limited low-level heating for much of the day has started to dissipate over the last few hours everywhere except southeast New Mexico. These cloud breaks have allowed surface temperatures to increase into the mid 60s. In addition to surface heating, gulf moisture has advected northwestward through the day with surface dewpoints in the low 60s near the New Mexico border. This has led to MLCAPE around 1500 J/kg in southeast New Mexico extending southward toward Big Bend National Park. A bit more surface heating may be possible before storm initiation, but low-to-mid level ascent has already started to arrive and storm initiation is likely soon. The 18Z MAF sounding showed a favorable wind profile with deep layer shear around 50 knots and effective SRH around 275 m2/s2. This wind profile is expected to become even more favorable into the early evening with 700mb flow strengthening from 35 knots to near 60 knots after 00Z and effective SRH increasing above 500 m2/s2. The biggest question will be whether isolated supercells can develop ahead of the Pacific front this afternoon. The HRRR continues to develop a few isolated storms in southeast New Mexico this afternoon with surface temperatures near 70 degrees. If isolated supercells do develop in this environment, the thermodynamic and kinematic environment will be extremely favorable for tornadoes. However, quick storm motion may quickly take storms out of the better instability which may limit the opportunity for low-level mesocyclone organization within this favorable environment. Farther south into the Trans Pecos (where GOES16 visible imagery shows a thickening cumulus field), if any storms can develop they will remain in better instability for a longer period after initiation, making the threat for tornadoes more likely. However, the threat for isolated storms ahead of the Pacific front in this area appears less likely as the better forcing remains farther north. Independent of earlier storm development, numerous storms are expected to develop along the Pacific front this evening and quickly become linear. The primary threat from these later storms will be wind, especially given the strength of the lower tropospheric flow. A tornado watch is likely at some point, but it remains unclear whether it will be needed for earlier supercell development this afternoon or frontal development this evening. ..Bentley/Thompson.. 03/12/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EWX...SJT...LUB...MAF...ABQ...EPZ... LAT...LON 30370488 31170492 31930497 32490494 32980485 33680430 33910383 33920330 33780295 32940262 32250233 31190186 29970169 29690185 29670241 29400275 29040290 28860318 29190396 29440442 29800472 30370488 NNNN