ZCZC SPCSWOMCD ALL
ACUS11 KWNS 281815 
SPC MCD 281815 
WAZ000-ORZ000-282145-

Mesoscale Discussion 0177
NWS Storm Prediction Center Norman OK
1215 PM CST Wed Feb 28 2024

Areas affected...the northern and central Cascades in Washington and
far northern Oregon.

Concerning...Heavy snow 

Valid 281815Z - 282145Z

SUMMARY...2 to 3 inch per hour snowfall rates are likely above 4000
feet this afternoon.

DISCUSSION...A plume of deep moisture (PWAT of 0.81" on the UIL 12Z
RAOB) continues to be transported into the Pacific Northwest by
strong low to mid-level flow ahead of an approaching mid-level
trough. Current snowfall levels are observed around 4000 feet which
should stay consistent through the afternoon. The 12Z UIL RAOB
sampled a 50 knot southwesterly low-level jet centered around 775mb.
RAP forecast soundings show winds veering slightly and increasing to
60 to 65 knots around 20-22Z. This should represent a maximum in
orographic ascent and snowfall rates during the afternoon. Snowfall
rates of 3 inches per hour are likely during that period with
locally higher rates, particularly at higher elevations. Heavy
snowfall rates will persist into the late afternoon before waning
after 00Z as low-level flow starts to weaken and PWAT values
decrease.

..Bentley.. 02/28/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PDT...SEW...PQR...

LAT...LON   46932225 47132198 47342189 47562176 47892181 48072193
            48442220 48552228 48822230 48942228 49022227 49072095
            48412119 47852119 47302129 45842145 45472147 45132168
            44912210 44862234 45102240 45292221 45542221 45682230
            45942245 46052258 46202263 46402255 46542248 46672251
            46762252 46862242 46932225 

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