A strong Pacific system moved through the area and over modified Arctic air. This resulted in widespread snow.
Every event with a place to put it; 12 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 strong Pacific system moved through the area and over modified Arctic air. This resulted in widespread snow.
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 13, 9:23 PM PST, 3 hours 37 minutes earlier.
Area Forecast Discussion...Updated
National Weather Service Pendleton OR
923 PM PST Tue Dec 13 2016
Updated Aviation Discussion
.UPDATE...The forecast scenario is coming into focus for a major
winter storm to impact most of the area beginning late tonight
through Wednesday evening. The latest 00Z NAM continues to be rather
aggressive in lifting the precipitation shield northward into
southern Washington and cutting off the snow in portions of Grant
and Crook Counties in Oregon. If this proves correct it will temper
the current snow forecast a bit in the south and bolster it in the
north. Will wait for the 00Z GFS run to come in before adjusting
the QPF and snow amounts. Overall the forecast is in very good
shape. Much of the region will see significant snow and some areas
near the east slopes of the Oregon Cascades including the Bend/
Redmond area are likely to see very heavy snow with this system.
78
&&
.AVIATION...06Z TAFs...Expect MVFR/VFR cigs at KDLS, KPSC and KYKM
through tonight and VFR vsby expected at all TAF sites except KRDM
and KBDN through 18Z. Conditions deteriorate from 18Z to
21Z at KDLS, KYKM, KPSC, KPDT, KALW due to stratus cloud decks
coming way down to produce LIFR cigs and -SN/SN/+SN producing VLIFR
vsby. Northerly upslope flow will keep LIFR cigs at KRDM and KBDN
over the next 24 hours with snow developing at KRDM and KBDN by 12Z
Wednesday, which produces VLIFR vsby at KRDM and KBDN through
Wednesday afternoon. Winds will remain under 10 kts for the next 24
hours. 76
&&
.PREV DISCUSSION... /issued 450 PM PST Tue Dec 13 2016/
SHORT TERM...Tonight through Wednesday night...The strong and wet
Pacific system is still on track to move into the region late
tonight. The surface low with this system looks to track relatively
quickly across southern Oregon to central Idaho Wednesday and
Wednesday night. Precip will spread over most of the area Wednesday
and Wednesday evening. The air mass over the region will be quite
cold and snow will be the main precip type. Many locations should
see snow accumulation ratios of 14 to 1 or higher. Precip amounts
will be highest over central Oregon where northeast to east low
level flow will result in upslope affects that will enhance precip
development. Thus this area should see significant snows between 10
and 20 inches before precip decreases late Wednesday evening. And
warnings will be issued for this area. A good portion of the rest of
the area will see good snow accumulation with the system's warm
front Wednesday and Wednesday evening. As such a number of warnings
and a few advisories will be issued. Will go with warnings for the
Washington Lower Basin and Foothills zones, as snow amounts look to
be in the 3-6 inch range at this time. There is the potential that
snow amounts in these two zones could be lighter if the system
speeds up beyond the current timing. The area that should see the
least amount of snow is Kittitas county in central Washington where
only an inch or two is expected. At this time will not issue any
highlights for the Kittitas Valley. Snow levels could rise briefly
to between 4000 and 5000 feet Wednesday evening over southern
portions of Crook and Grant counties. As a result some valleys may
see a brief mix of rain or freezing rain. Accumulations of freezing
rain will be light. 90
LONG TERM...Thursday through Saturday night. The NAM12 and the
ECMWF are faster than the GFS at sliding the frontal band into
southeast Oregon Thursday evening...but the current forecast has
about 20-40 percent PoPs for our far eastern zones during that time
and will keep these PoPs to be on the safe side. From 09Z-18Z
Friday...only scattered light snow showers are expected in the
eastern mountains. There may be flurries or light snow along the
Blue Mtn Foothills Friday morning as well due to weak low level
upslope. Skies will clear out Friday under a N-NW flow aloft...and a
northerly surface gradient will tighten in eastern Washington. Areas
from the Tri-Cities to Connell and in the Yakima Valley could have
wind chills in the single digits where north winds will be 10-20
mph. Radiational cooling Friday night will cause temperatures to
plummet below 0F in many snow-covered areas...and Bear Valley and
Ukiah could reach near -13F. A dry forecast is in store Friday night
and Saturday...but the cold air mass will remain entrenched and
afternoon temperatures on Saturday will only be in the teens and
20s. Almost all of the forecast area will remain dry and cold
Saturday night with the exception of the east slopes of the WA
Cascades where a slight chance of snow is forecast due to a warm
front bringing precipitation over western Washington may spill over
to the east side. Wister
Sunday through Tuesday night...An upper level ridge of high pressure
will be offshore Sunday/Sunday night with a weak mid/upper level
disturbance moving south on the eastern flank of the ridge and
through the forecast area for a chance of snow Sunday and Sunday
night in the Blue Mountains, the Wallowa Mountains and along the
east slopes of the WA/OR Cascades and a slight chance of snow at
lower elevations through the day on Sunday. Monday the
aforementioned ridge moves inland and brings sinking air and dry
conditions to the forecast area. Monday night through Tuesday night
there are differences appearing in the 12z GFS and ECMWF model runs
in terms of the strength and speed of movement of the next upstream
mid/upper level shortwave moving east toward the Pacific Northwest./
I split the difference and kept chance of mountain snow and a slight
chance of valley and Columbia Basin snow for Monday night. Tuesday
looks to be the best day for snow likely in the Blue Mountains, the
Elkhorn Mountains and the Wallowa Mountains as well as along the
east slopes of the WA/OR Cascades. Snow levels will remain at the
floor of the Lower Columbia Basin from daybreak on Sunday to
daybreak on Wednesday. High temperatures on Sunday will be in the
mid to upper 20s, in the upper teens to lower 20s in the mountains.
Highs on Monday will be a tad warmer, in the upper 20s to lower
30s,except 20 to 30 in the mountains. Tuesday will have highs in the
lower to mid 30s, except in the mid 20s to lower 30s mountains.
Polan
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 14 20 17 24 / 10 60 90 20
ALW 17 21 19 26 / 10 30 90 20
PSC 14 22 17 26 / 0 30 80 20
YKM 12 22 13 27 / 0 20 70 10
HRI 15 22 17 25 / 10 60 90 20
ELN 8 20 15 26 / 0 10 50 10
RDM 14 20 10 31 / 20 100 90 20
LGD 15 28 21 31 / 10 70 90 40
GCD 14 30 24 34 / 10 100 90 40
DLS 23 27 18 31 / 10 90 80 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Storm Warning from 1 AM Wednesday to 4 AM PST Thursday
for ORZ509.
Winter Storm Warning from 10 AM Wednesday to 4 AM PST Thursday
for ORZ044-049-050-503-507.
Winter Weather Advisory from 10 AM Wednesday to 4 AM PST
Thursday for ORZ502.
Winter Storm Warning from 4 AM to 11 PM PST Wednesday for ORZ505-
506-510-511.
Winter Storm Warning from 10 AM to 11 PM PST Wednesday for
ORZ041-508.
WA...Winter Weather Advisory from 10 AM Wednesday to 4 AM PST
Thursday for WAZ030-520.
Winter Weather Advisory from 1 PM to 11 PM PST Wednesday for
WAZ027.
Winter Storm Warning from 1 PM Wednesday to 4 AM PST Thursday
for WAZ028-029.
Winter Storm Warning from 10 AM to 11 PM PST Wednesday for
WAZ024-521.
&&
78The national radar mosaic for the moment the first event began.
12 heavy snow. Local standard time, as filed.
Measured heavy snow accumulation of 21 inches since early morning, 5 miles north of La Pine. Includes 7 inches of new snow in last 3 hours.
Measured heavy snow accumulation of 14 inches, 3 miles east-northeast of Bend.
Estimated heavy snow accumulation of 10 inches in the Ochoco mountains, 15 miles west-southwest of Mitchell. Also measured heavy snow of 7 inches, 3 miles southeast of Post.
Measured heavy snow accumulation of 6 inches, 9 west-southwest of Service Creek in Wheeler county.
Measured heavy snow accumulation of 6 inches, 2 miles south-southwest of Grass Valley in Sherman county.
Measured heavy snow accumulation of 6 inches at the Lucky Strike Snotel, 6 miles west-southwest of Starkey in Union county. A 12 hour accumulation.
Measured heavy snow accumulation of 7 inches at Lexington.
Measured heavy snow accumulation of 4 inches, 5 miles south-southwest of Chenoweth. Another report of around 4 inches in Arlington.
Estimated heavy snow accumulation of 6 inches at Pilot Rock. Also measured heavy snow of 4 inches at Athena.
Measured heavy snow accumulation of 6 inches, 2 miles north of Hermiston.
Measured heavy snow accumulation of 6.5 inches since the evening of the 14th, 5 miles north-northeast of La Grande.
Estimated heavy snow accumulation of 5 inches at Lostine.
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: 665629, 665631, 665640, 665639, 665633, 665643, 665641, 665637, 665644, 665648, 665649, 665650.