East winds ahead of an approaching low pressure system brought temperatures down below freezing across the area ahead of the approaching precipitation. This lead to a mix of freezing rain, sleet, and snow across the area.
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 PQR wrote it up.
East winds ahead of an approaching low pressure system brought temperatures down below freezing across the area ahead of the approaching precipitation. This lead to a mix of freezing rain, sleet, and snow across the area. While areas farther north saw more of a snow/sleet mix before a changeover to freezing rain then rain, areas in Lane County saw freezing rain for most of this event, causing power outages, damage to trees, and many car accidents around Eugene and Springfield.
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 Portland, OR wrote its last area forecast discussion before the first event at Dec 13, 8:59 PM PST, 6 hours 1 minute earlier.
Area Forecast Discussion...Corrected
National Weather Service Portland Oregon
859 PM PST Tue Dec 13 2016
.SYNOPSIS...High pressure east of the Cascades will lead to
increasing east winds this afternoon with the strongest tonight and
Wednesday. This will set the stage for a winter mix of precipitation
to the valley floors as moisture from the next system spreads north
through the day Wednesday and continues through Wednesday
evening, moving east by Thursday morning. The wintry pattern will
remain through the weekend with the coldest air of the season and
snow chances each day.
&&
.SHORT TERM...Today through Thursday...Beautiful day today with
mostly sunny skies, and light winds, but this is just the calm before
the storm before the region is battered with another round of winter
weather. The TTD-DLS gradient is now 6.5 mb up from 3.5 mb earlier
this afternoon and winds have responded across the western Gorge
zones. The stronger offshore flow will pull arctic air from eastern
Washington/Oregon into the Willamette Valley and drop temperatures to
below freezing for the entire area by morning. This will lead to a
complicated precipitation type forecast for the southern Willamette
Valley when the precipitation arrives Wednesday
morning. Confidence is high that surface temperatures will be below
freezing, but temperatures aloft are a bit uncertain. This elongated
surface low, associated with a positive tilt trough aloft makes for
a complicated forecast. Storm-relative warm air advection is
sufficient for moderate precipitation along and north of the front,
but given the progressive nature of the surface low, the strongest
flow remains mostly parallel to the gradient. This may limit the
northward push of the warm nose aloft and the rain/snow line may
stay further south even than currently forecast. In addition, the
tropical connection on water vapor would suggest that moisture
should not be an issue with this system. However, the lack of strong
backed isentropic flow to transport moisture northwest of the
surface low is a mitigating factor to heavier snowfall amounts.
Also, there will be considerable dry air to overcome, and areas
outside of the better moisture transport may lose some of the
moisture while the column is being saturated. This will especially
be an issue in areas near the Gorge where the dry air transport will
be most prevalent.
In addition to the aforementioned concerns, a tight gradient between
moderate to heavy snow accumulations and light accumulations is a
cause for concern. A 25 to 50 mile difference in the track of the
surface low, or a slightly stronger/weaker shortwave aloft can make
the difference between a dusting or 3 to 5 inches for the Portland
metro area and could make the difference between all snow, ice, or
all rain for Eugene. 00Z models are in much better agreement than 24
hours ago and feel fairly confidenc in overall forecast. However
uncertainly whether the south Willamette valley and parts of the
central Willamette valley will get more ice than expected is still a
concern. NAM BUFR soundings show a period of freezing rain through
Wed afternoon which could bring greater impacts to those areas.
remainder of previous discussion follows.
Taking a look at cross sections through the cold sector, there is an
area of negative EPV above the frontogenesis during the afternoon to
early evening for areas between PDX and SLE. This area of CSI will
likely lead to snow bands which will lead to isolated areas of higher
snowfall accumulations. The lucky (or unlucky) souls underneath one
of these bands, could see snowfall totals an inch or two in excess of
areas surrounding them.
Finally, the timing of winter event could cause significant issues
for the Wednesday evening commute for the Portland/Vancouver metro
area. Snowfall accumulation will start light which may only lead to
wet roads, however, as soon as the sun begins to set (~4PM) at the
same time the heavier precipitation arrives, the roads may become
very treacherous. Regardless of how much snow has accumulated by this
time, the combination of refreezing roads with a layer of snow on
top, could lead to more dangerous roads than a snow packed few
inches. /Bentley
.LONG TERM...Thursday night through Tuesday...Upper level trough
associated with our midweek snow event hangs back across the Pac NW
Thu night and Fri, with a couple lingering flurries possible but
little to no accumulation expected. Otherwise...cold, modified
arctic high pressure will settle into the Pac NW, with the coldest
850 mb temps east of the Cascades as usual. Assuming some snow cover
left behind by Wednesday's event, low temps could get quite cold
Thursday and Friday nights...perhaps well down into the teens for
some of the colder Willamette Valley spots like Hillsboro and
McMinnville. With the 12z ECMWF showing 850 mb temps as low as -8 to
-10 deg C, temperatures will struggle to climb much above freezing
despite a good bit of sunshine. So...whatever snow does accumulate
Wednesday will probably stick around for a while, bringing up the
issue of a melt/re-freeze cycle which could keep roads locally slick
in the lowlands for a few days...especially night and morning.
The 18z GFS is similar to the 12z ECMWF in bringing a clipper-like
system across WA and into the Rockies Sunday. This could bring a
brief dusting of snow to the lowlands Sat night/early Sun, before
flow turns onshore and causes the snow level to rise back into the
foothill elevations later Sunday. The 12z GEM drops a somewhat
stronger low down the coast early Sunday, which could result in more
accumulating lowland snow than what the GFS/ECMWF suggest. However
this appears to be an outlier and we largely disregarded this
solution for now. Models show decent agreement on gradual moderation
of our cold air early next week, with some potential for a modest
atmospheric river system to bring significant rain by Tuesday as the
flow pattern across the North Pacific turns increasingly progressive
and zonal. Weagle
&&
.AVIATION...The offshore gradient strengthens tonight for
primarily VFR conditions. There is the potential for IFR/LIFR to
re-form in the central and southern interior valleys after 06Z
Wed. Warm-frontal overrunning precipitation reaches Lane County
around sunrise, which will fall as snow except along the coast.
Expect IFR to MVFR conditions over the far south around 15Z, then
spreading north thereafter. Precipitation inland will be as snow,
with the potential for -FZRA south of KS12 in the afternoon.
Generally widespread IFR to MVFR across the area by afternoon,
except for SW Washington where precipitation will be less.
KPDX AND APPROACHES...East winds picking up this evening and
through the overnight hours. Gusts to 40 Kt likely from KPDX to
KTTD after 12Z Wed. Moisture advancing from the south expected to
reach the terminal around 20Z. Snow increases briefly around 00Z
Thursday, likely lowering flight conditions to at least MVFR.
Bowen
&&
.MARINE...Offshore flow pattern will prevail through Wed morning.
Wind speeds starting to come up over the northern waters this
evening with some gusts to around 20 kt. Small craft advisory for
wind continues for the north waters starting midnight tonight through
Wednesday afternoon. The advisory will be mainly for frequent
gusts instead of persistent sustained wind.
Models show a surface low moving into the North California waters
late tonight, then lifting northeast Wed. This will result in
backing wind, from E to NNE. Wind speeds begin to ease Wed
evening. In the longer term, wind speeds remain near or below 15
kt models through the weekend. Models diverge early next week, but
there is reasonable confidence that small craft advisory wind
speeds develops late Sun night or Mon morning, with some potential
for low-end gales.
Seas are forecast to remain well below 10 feet for the next
several days. Sea conditions will become more wind wave driven
and possibly quite choppy at times, however. Bowen/Weishaar
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Storm Warning from noon Wednesday to 2 AM PST Thursday
for Central Columbia River Gorge-Upper Hood River Valley-
Western Columbia River Gorge.
Winter Storm Warning from 8 AM Wednesday to 4 AM PST Thursday
for Northern Oregon Cascade Foothills-Northern Oregon
Cascades.
Winter Weather Advisory from 4 AM Wednesday to 2 AM PST
Thursday for Cascade Foothills in Lane County.
Winter Storm Warning from 4 AM Wednesday to 4 AM PST Thursday
for Cascades in Lane County.
Winter Weather Advisory from 11 AM Wednesday to midnight PST
Wednesday night for Greater Portland Metro Area.
Wind Advisory from midnight tonight to 8 PM PST Wednesday for
Greater Portland Metro Area.
Winter Weather Advisory from 6 AM Wednesday to midnight PST
Wednesday night for Central Coast Range of Western Oregon-
South Willamette Valley.
Winter Weather Advisory from 8 AM Wednesday to midnight PST
Wednesday night for Central Willamette Valley.
WA...Winter Storm Warning from noon Wednesday to 2 AM PST Thursday
for Central Columbia River Gorge-Western Columbia River
Gorge.
Winter Weather Advisory from 11 AM Wednesday to midnight PST
Wednesday night for Greater Vancouver Area.
Wind Advisory from midnight tonight to 8 PM PST Wednesday for
Greater Vancouver Area.
PZ...Small Craft Advisory for winds from midnight tonight to 4 PM
PST Wednesday for Coastal Waters from Cape Shoalwater WA
to Cascade Head OR out 60 nm.
&&
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.8 heavy snow, 4 winter storm. Local standard time, as filed.
The Cascade Summit SNOTEL reported 14 inches of snow and the McKenzie SNOTEL reported 11 inches of snow with this storm.
Snow followed by sleet and freezing rain. There were reports of 0.25 to 0.5 inches of ice and sleet reported near this area, with power outages.
Snow, followed by freezing rain. The freezing rain turned into a major ice storm occurred in Eugene and the vicinity with 0.5 to 1.0 inch of ice accumulation observed. There was significant damage to trees and power lines, and fairly widespread power outages across the region. 15,000 people were without power.
Snow followed by freezing rain. There were reports of 0.5 to 1.0 inches of ice accumulation in the, with 0.88 inch of ice accumulation reported by local media just east of Springfield. Many power outages across the area.
The Marion Forks SNOTEL reported 15 inches of snow, and the Smith Ridge SNOTEL reported 13 inches of snow. An avalanche caused by heavy snow also closed US 20 across Santiam Pass.
In Salem there were reports of 3 to 5 inches of snow. There were also numerous reports of vehicles that got stuck and huge traffic jams from the snow.
There was a report of 0.4 inch of ice accumulation near Sodaville.
Parkdale had 5 inches of snow.
There was a report of 6 inches of snow at Beacon Rock.
Hood River reported 3 to 6 inches of snow.
There were reports of 2 to 4 inches in and around the Portland Metro area, which brought traffic to a halt. Over 500 vehicles were left abandoned on area roads once they turned icy. This storm essentially shut down the city for the next two days, since weather remained cold and snow could not melt. 1200 kids were stuck at schools in Beaverton until 8pm. Other school buses were still stuck with kids on them at 8:30 pm that night.
Generally 4 inches of snow was reported from Warren in the Lower Columbia up the I-5 corridor to Castle Rock.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2016Every state in 2016This day in weather historyWarnings in Oregon, 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: 671054, 672260, 672262, 672263, 671053, 671085, 672249, 671071, 671075, 671076, 671109, 671110.