MD 0180 CONCERNING HEAVY SNOW FOR PORTIONS OF THE SIERRA IN NORTHERN CALIFORNIA
Mesoscale Discussion 0180
NWS Storm Prediction Center Norman OK
0651 PM CST Thu Feb 29 2024
Areas affected…Portions of the Sierra in northern California
Concerning…Heavy snow
Valid 010051Z – 010445Z
SUMMARY…Snowfall rates are expected to increase to near 2-3 inches
per hour with localized blizzard conditions across portions of the
Sierra in northern California in the 01-06Z time frame.
DISCUSSION…Within the base of a deep midlevel cyclone centered off
the British Columbia coast, the exit region of a robust
mid/upper-level jet streak will impinge on the northern Sierra
during the next few hours, while a related cold front moves
southeastward across the region. The associated increase in
large-scale ascent/frontal forcing, augmented by strengthening
upslope flow, will continue to favor an increase in precipitation
rates into tonight. This increasing ascent is already becoming
evident in low/mid-level water-vapor loops and regional radar data.
Given the overlap of strengthening ascent and influx of Pacific
moisture (including a relatively deep and saturated dendritic growth
zone), snowfall rates are expected to increase to near 2-3 inches
per hour over portions of the northern Sierra (with locally higher
rates possible). Current thinking is that these heavier rates will
become more persistent in the 01-06Z time frame as the cold front
continues southeastward (supported by the latest high-resolution
guidance), with heavy snow persisting into the overnight hours. The
highest rates will likely occur at elevations above 5000-6000 feet.
In addition, strengthening low-level flow accompanying the
mid/upper-level speed maximum and cold front will likely support
localized blizzard/whiteout conditions, given the potential for 50+
mph gusts and the heavy snowfall rates.
..Weinman.. 03/01/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…REV…HNX…STO…
LAT…LON 38221950 38021972 38242005 38922046 39492080 39712112
39912108 40022080 39652042 38681989 38221950
