MD 2080 CONCERNING HEAVY SNOW FOR THE HIGHER TERRAIN OF THE SIERRA IN NORTHERN CALIFORNIA
Mesoscale Discussion 2080
NWS Storm Prediction Center Norman OK
1141 AM CST Sat Dec 31 2022
Areas affected...the higher terrain of the Sierra in northern
California
Concerning...Heavy snow
Valid 311741Z - 312345Z
SUMMARY...Heavy snow is expected to increase in coverage across the
higher terrain of the Sierra in northern California through the
afternoon into early evening.
DISCUSSION...A mid-level trough and accompanying stream of deep
moisture continues to impinge on the higher terrain of the Sierra in
northern CA. Strong deep-layer ascent along the windward side of the
Sierra should lift the deep moisture to a saturated dendritic growth
zone, favoring heavy snow production. The depth of the rich
moisture, the presence of weak buoyancy, and combined orographic and
dynamic lift of moist and buoyant air may foster snowfall rates up
to the 3-5 inch/hr range, at least on a localized basis and
particularly above 6000 ft elevations. Latest high-resolution
guidance consensus suggests that the heavier snowfall rates should
begin sometime between 18-20Z and become more widespread in the
higher elevations in the 21-01Z time frame.
..Squitieri.. 12/31/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...VEF...REV...HNX...STO...
LAT...LON 39692049 38941999 38391942 38141925 37741893 37481857
37191831 36961835 36991866 37421925 37921972 38642031
39062057 39332062 39682064 39692049
