A Pacific system brought heavy snow to the Washington Cascade east slopes, the Blue mountains, Wallowa county and the Grande Ronde Valley.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PDT wrote it up.
A Pacific system brought heavy snow to the Washington Cascade east slopes, the Blue mountains, Wallowa county and the Grande Ronde Valley.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Pendleton, OR wrote its last area forecast discussion before the first event at Dec 26, 1:18 PM PST, 4 hours 42 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
118 PM PST Mon Dec 26 2016
.SHORT TERM...Tonight through Wednesday night. Winter Storm Warnings
for heavy snow were posted early this morning for the East Slopes of
the Cascades (WA/OR), the Blue Mountains (WA/OR), the Grande Ronde
Valley and Wallowa County. These are in effect this evening through
late Tuesday night. No additional winter highlights will be issued
during the afternoon forecast package. A warm front with weak warm
air advection (WAA) but strong upper level support has approached
the Washington Coast and will make its way to the Cascade Range
around sunset this evening then the remainder of the forecast area
tonight. The NWS offices in Seattle and Portland have warnings out
for 1 to 3 feet of snow along the west side of the Cascades...and
snow will spill over to the east slopes where 10 to 20 inches are
expected. The northern Blue Mountains will get hit hard as well with
10 to 18 inches of new snow. Snowfall rates of 1 inch per hour can
be expected at times in these areas. In addition...gusty winds will
cause blowing and drifting of snow. In the Grande Ronde
Valley...near white-out conditions may occur tonight. Although the
Wallowa Valley and Imnaha Valley may only get advisory amounts of
snow due to precipitation shadowing off the Blue Mtns...other areas
of Wallowa County will observe heavy snow.
Models are hinting at mountain wave activity along the central
Oregon Cascades late tonight and Tuesday. Cross sections of high
resolution models do not indicate the mountain wave accelerating to
the surface. However...sudden gusts to 35 mph are possible and will
include this in the wind gusts overnight in portions of Central
Oregon.
Another weather concern with the approaching system will be the
precipitation type late tonight and Tuesday morning. Due to the weak
WAA but increasing winds...believe any transition from snow to rain
will be quick enough that any freezing rain will be limited...or
none at all. Snow levels will rise to 2000 feet in South Central WA
and 3500 feet in Central Oregon on Tuesday. Will keep the slight
chance of freezing rain for the Columbia Basin and surrounding
valleys down to Central OR with the best chance from Midnight to 10
AM Tuesday.
An upper level ridge will build over the Pacific NW Wednesday with
precipitation tapering off during the day. Most of the forecast
area will be dry Wednesday afternoon and Wednesday night with the
exception of the East Slopes of the WA Cascades north of Naches that
will have a chance of light snow associated with a warm front over
western WA. Wister
.LONG TERM...Thursday through Monday. Mostly dry conditions will
continue into Thursday with northerly flow ahead of a low pressure
system that is expected to drop south along the coast with a band of
moisture pushed south over the region on Friday. That low will move
into southern California with a break over the area on Saturday with
another low dropping through the flow for Sunday and then moving
east on Monday followed by a drier northeast flow. The models have
come into much better agreement on this feature and thus have
increased the chance of mainly snow on Sunday and then cooler
temperatures for Monday. 93
&&
.AVIATION...00Z Tafs. Mid and high clouds will continue to
overspread the region with light snow with MVFR VSBYs reaching KDLS
at by 03z and other sites by 06z and continue through 18z Tuesday
with the showers becoming scattered after 18z. winds will be under
10kt through 06z, and become S to SW 10-20kts after 6Z and continue
through 18z. 93
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 28 40 30 38 / 80 40 20 10
ALW 31 42 32 39 / 80 40 30 10
PSC 31 42 31 39 / 70 20 10 0
YKM 23 41 25 39 / 70 20 20 0
HRI 28 40 31 38 / 70 20 10 0
ELN 22 37 26 36 / 90 30 20 10
RDM 23 41 23 35 / 50 30 30 10
LGD 19 34 25 32 / 90 70 50 30
GCD 23 37 22 33 / 80 50 50 30
DLS 32 42 32 38 / 80 50 50 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Storm Warning from 10 PM this evening to 4 AM PST
Wednesday for ORZ049-050-502-503.
Winter Storm Warning from 7 PM this evening to 4 AM PST
Wednesday for ORZ509.
WA...Winter Storm Warning from 10 PM this evening to 4 AM PST
Wednesday for WAZ030.
Winter Storm Warning until 4 AM PST Wednesday for WAZ520.
&&
85/93/93The national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
Measured heavy snow accumulation of 12 inches, 7 miles north-northwest of Easton in Kittitas county. This is in the northern portion of the zone.
Measured heavy snow accumulation of 6.9 inches, 1 mile south-southwest of Trout Lake in Klickitat county. This in the southern portion of the zone.
Measured heavy snow accumulation of 12 inches overnight, 1 west-southwest of Ski Bluewood in Columbia county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2016Every state in 2016This day in weather historyWarnings in Washington, December 2016
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 665656, 665657, 665658.