MD 0001 CONCERNING HEAVY SNOW FOR HIGHER TERRAIN AREAS OF THE MOGOLLON RIM IN CENTRAL INTO EAST-CENTRAL ARIZONA
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
