A strong trough of low pressure moved through eastern Oregon producing areas of heavy snow and gusty winds.
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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 BOI wrote it up.
A strong trough of low pressure moved through eastern Oregon producing areas of heavy snow and gusty winds.
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 Boise, ID wrote its last area forecast discussion before the first event at Dec 20, 9:56 AM MST, 5 hours 4 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
956 AM MST Tue Dec 20 2016
.DISCUSSION...Update forecast for slower timing of ongoing Pacific
storm system today. Models in good agreement with the late
morning onset of precipitation across Treasure Valley. Warm air
aloft has been steadily moving in across SE Oregon with
temperatures in the mid 40s around 5000 feet. 12z Sounding showed
temperatures reaching 32 degrees around 800 mb /6000 feet/ and
expect the temperatures to continue to warm today ahead of the
cold front. The Treasure Valley will remain below freezing and
thus should see a mix of snow, freezing rain and sleet between 11
am and 5 PM. Precipitation will likely start out as Freezing rain
or sleet then switch to snow this afternoon with the heavier
precipitation band ahead of the cold front. Have already received
reports of freezing rain in the Treasure Valley. Western Magic
Valley will likely see less snow and more rain as the
precipitation arrives this afternoon when temperatures climb above
freezing. Lowered snow amounts to around 1-2 inches in the
Treasure Valley which is likely optimistic given the likely mixed
precipitation this afternoon. The Precipitation will end quickly
with passage of a cold front, between 19z-21z in SE Oregon and
21z-01z in SW Idaho. Update forecast will be out shortly.
&&
.AVIATION...Widespread MVFR and local IFR in -SN, -FZRA, and -RA
today, as a cold front approaches from the west. BOI will likely
start as -FZRA around 18Z, then transition to -SN this afternoon.
Mountains will be obscured. The cold front will move east across
Oregon this afternoon, reaching the Oregon/Idaho border around 00Z
and BOI around 01Z. The bulk of precipitation will fall ahead of the
front, with drier conditions overall this evening. Surface winds
will be 5 to 15 KTS /with gusts to 25 KTS/ out of the S-SW this
afternoon, trending W-NW with frontal passage. Westerly winds aloft
will average 35 KTS at 10K FT. Winds will generally subside after
midnight, supporting fog development throughout mountain valleys.
&&
.PREV DISCUSSION...
SHORT TERM...Today through Wednesday...Pacific system already
producing light snow in northern southeast Oregon as of 3:30 AM
MST. Will see precipitation steadily push south and east through
the region as the sun begins to rise. Today's system is a tricky
one due to warming aloft ahead of tonight's cold frontal passage.
Will see snow mix with rain along the Nevada border where the
atmosphere will have a chance to warm the longest ahead of the
incoming front. Other areas as far north as a Burns-Boise line
could see areas of freezing rain and sleet as the surface remains
cold and the temperatures warm above freezing aloft. Winter Storm
Warnings in Baker County, West Central Mountains and Upper Weiser
River Valley, and the Boise Mountains for snow. Winter weather
advisories continue for the Upper and Lower Treasure Valleys as
the ground remains cold, with snow and possible sleet and freezing
rain by midday today. Cold front expected to pass through the
region late today, quickly drying out and cooling 5-10 degrees in
its wake. Wednesday will be dry with light winds.
LONG TERM...Wednesday night through Tuesday...Mostly clear Wednesday
night and Thursday under flat upper ridge. Weak following upper trough
will bring light snow to northern areas Thursday night. Southern areas
should stay dry. Deep Pacific storm off nrn California Friday will
push a warm front northward through our area Friday...with significant
pcpn Friday night and Saturday when the whole storm and associated
upper trough come inland. Clearing and colder Christmas Day under
nwly flow ahead of transitory upper ridge...then another potential
Pacific storm with cold air in place Sunday night through Tuesday.
However...GFS and ECM disagree on that storm. Surface inversions
will be slow to mix out in the low valleys but higher elevations
will warm...possibly resulting in mixed pcpn in the valleys Thursday
night and again near the warm front Friday and Friday night.
Otherwise...pcpn should be in the form of snow.
AVIATION...Areas of MVFR ceiling/visibility in fog/stratus until
12Z followed by snow from the northwest with general IFR and mountain
obscuration 15Z-00Z. Improving to VFR from northwest to southeast
beginning 00Z Wednesday and VFR all areas by 06Z Wednesday...except
patchy IFR fog forming in the valleys. Surface wind mainly SE 5-15
kts except ne 10-20 kts near KJER. Winds aloft near 10 kft swly 20
kts...becoming wnwly 25-30 kts after 18Z.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 5 PM MST this afternoon
IDZ011-013-033.
Winter Weather Advisory until 5 PM MST this afternoon IDZ012-014.
OR...Winter Storm Warning until 4 PM PST this afternoon ORZ062.
Winter Weather Advisory until 5 PM MST this afternoon ORZ064.
&&
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DISCUSSION...JdS
AVIATION.....MT
PREV SHORT TERM...AB
PREV LONG TERM....LCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
916 AM MST TUE DEC 20 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0905 AM FREEZING RAIN EMMETT 43.87N 116.49W
12/20/2016 U0.00 INCH GEM ID TRAINED SPOTTER
TRAINED SPOTTER REPORTING FREEZING RAIN IN EMMETT, IDAHO.
&&
THIMMESCHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
1053 AM MST TUE DEC 20 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1037 AM FREEZING RAIN 3 WNW MERIDIAN 43.63N 116.46W
12/20/2016 E0.00 INCH ADA ID UNKNOWN
MIXED WITH A LITTLE SLEET.
1048 AM FREEZING RAIN EAGLE 43.69N 116.36W
12/20/2016 E0.00 INCH ADA ID UNKNOWN
FREEZING RAIN FALLING IN EAGLE AND 20 DEGREES.
1048 AM FREEZING RAIN 1 SE MERIDIAN 43.60N 116.39W
12/20/2016 E0.00 INCH ADA ID NWS EMPLOYEE
FREEZING RAIN MIXED WITH SLEET.
&&
JSMITHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
1137 AM MST TUE DEC 20 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1132 AM FREEZING RAIN 5 SSW CALDWELL 43.60N 116.72W
12/20/2016 E0.00 INCH CANYON ID TRAINED SPOTTER
&&
JALLENThe national radar mosaic for the moment the first event began.
1 heavy snow. Local standard time, as filed.
The COOP observer at Halfway reported 6 inches of new snow and Baker City EM reported 4 inches in Baker City.
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: 672273.