ZCZC SPCSWOMCD ALL ACUS11 KWNS 242001 SPC MCD 242001 NMZ000-COZ000-UTZ000-AZZ000-NVZ000-242200- Mesoscale Discussion 1342 NWS Storm Prediction Center Norman OK 0301 PM CDT Sat Jul 24 2021 Areas affected...Four Corners into southern Nevada Concerning...Severe potential...Watch unlikely Valid 242001Z - 242200Z Probability of Watch Issuance...20 percent SUMMARY...Several clusters of thunderstorms across northern New Mexico and southern Utah have recently shown signs of intensification. These storms and additional development may pose a risk for damaging winds or small hail this afternoon and evening. DISCUSSION...Within a monsoonal flow regime beneath a weak upper low, strong diurnal heating and weak ascent have allowed several clusters of thunderstorms to become established over portions of the Southwest in the last couple of hours. As heating and orographic ascent continue, additional thunderstorm development appears likely. Within the high PWAT airmass, SPC mesoanalysis indicates 500-1000 J/kg of MLCAPE has developed. While thermodynamics are favorable for robust updrafts, a blocking ridge of high pressure in the mid levels should limit flow aloft and resulting vertical shear to below 25 kts. A multicellular storm mode is expected with the stronger storms capable of damaging wind gusts and small hail. A locally greater risk of damaging wind gusts may develop if storm outflows are able to evolve into small clusters as suggested by some hi-res guidance. However, given the low predictability and expected limited severe threat, a watch is unlikely at this time. ..Lyons/Hart.. 07/24/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABQ...GJT...FGZ...SLC...VEF... LAT...LON 36521526 37381456 37601320 37611229 37571105 37230966 37010892 36630819 36250784 35800784 35230798 34800888 34740966 34721061 34851193 35021295 35191412 36521526 NNNN