ZCZC SPCSWOMCD ALL ACUS11 KWNS 011607 SPC MCD 011607 AZZ000-012200- Mesoscale Discussion 0001 NWS Storm Prediction Center Norman OK 1007 AM CST Sun Jan 01 2023 Areas affected...higher terrain areas of the Mogollon Rim in central into east-central Arizona Concerning...Heavy snow Valid 011607Z - 012200Z SUMMARY...Heavy snow is expected across the higher terrain areas of the Mogollon Rim through the afternoon, especially above 6000 ft. 2-3 inch/hr rates are possible and brief bouts of locally heavier rates cannot be ruled out. DISCUSSION...A coupled upper trough and surface-850 mb low are promoting deep-layer southwesterly flow across AZ, with a conveyor belt of deep moisture supporting widespread moderate to heavy precipitation to the region. Sub-freezing vertical profiles above 6000 ft should support mainly snow across the higher-terrain areas of the Mogollon Rim. Strong 850-700 mb warm-air advection should provide ample moisture and lift within the -12 to -17C dendritic growth zone to support 2-3 inch/hr snowfall rates at times. By mid to late afternoon, a strongly forced line of low-topped convection is expected to develop across portions of central into southern AZ. It is possible that weak slantwise convection could develop later this afternoon to the rear of the convective line if weak, elevated instability can extend far enough north toward the Mogollon Rim. As such, a brief instance or two of snowfall rates over 3 inches/hr could occur. The heavier snow rates may begin as early as 17Z across the far south-central Coconino County area in association with the preceding conveyor belt of precipitation (per latest high-resolution guidance). Heavier snow should develop southeastward to southern Apache County (near the NM border) from roughly 20Z-00Z in tandem with the post-squall line environment. ..Squitieri.. 01/01/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ... LAT...LON 34941172 34251001 34010926 33650918 33470949 33781025 34231101 34481149 34821178 34941172 NNNN