A large upper level trough extending over the Pacific Northwest and Intermountain region spread heavy snow across Southwest Idaho and Southeast Oregon.
Every event with a place to put it; 2 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 BOI wrote it up.
A large upper level trough extending over the Pacific Northwest and Intermountain region spread heavy snow across Southwest Idaho and Southeast Oregon.
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 23, 2:28 PM MST, 3 hours 32 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
228 PM MST Fri Dec 23 2016
.SHORT TERM...Tonight through Sunday...Winter weather advisories are
in effect through Saturday. A deepening upper level trough is
currently centered over the West Coast. The warm frontal band ahead
of the trough continues to produce snow across most of southwest
Idaho, while snow has ended at most locations in southeast Oregon.
Snow should taper off in southwest Idaho this evening, but increase
across the region late tonight through Saturday morning as the upper
level trough pushes inland. As the trough moves over our area
Saturday afternoon and evening, we can expect scattered snow showers
in the cold moist and unstable air, but little additional
accumulation is expected. Drier more stable northwest flow aloft on
Sunday will bring colder temperatures and partly cloudy skies, with
only a few flurries over the Idaho mountains.
.LONG TERM...Sunday night through Friday. Northwesterly flow aloft
will briefly bring cold and dry conditions for Monday. Monday
morning will be one of the coldest mornings of the year. Another
trough with ample moisture will pass by with a cold front late
Tuesday into Wednesday bringing snow to most of the area. The West
Central Mountains of Idaho and Boise Mountains along with Baker
county will get the most snow from the system. Models differ greatly
after Wednesday with the ECMWF showing a high amplitude ridge and
the GFS showing cold northerly flow with a polar frontal passage
next Friday. There is not aloFt of confidence in either solution but
the drier EC solution is favored. Temperatures are expected to
remain below normal through the period.
&&
.AVIATION...IFR/MVFR conditions in snow across SW Idaho this
afternoon. Snow will diminish at KEUL and KBOI but continue for
KMUO, KTWF and KJER ending by early evening. Snow could mix with
rain below 4k feet this afternoon. Surface winds: Generally 12 kts
or less, except in SE Oregon and the Magic Valley where gusts to 30
kts is likely. Winds aloft near 10 KFT MSL: Southwest 30-40 kts.
Weekend outlook...Another round of IFR/MFR snow is expected late
tonight across SE Oregon and early Saturday morning across SW Idaho
with passage of the cold front and upper level trough. Snow level
around 4K feet MSL through Saturday morning, then lowering to the
valley floors by Saturday afternoon. Snow ending across eastern
Oregon and the lower Snake River Valley Saturday night with
scattered showers remaining over the Central Mountains of Idaho.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 5 PM until 11 AM MST Saturday
IDZ011-013.
Winter Weather Advisory remains in effect until 5 PM MST Saturday
IDZ015-029-030.
Winter Weather Advisory remains in effect until 11 AM MST Saturday
IDZ012-014-016-033.
OR...Winter Weather Advisory from 5 PM /4 PM PST until 11 AM MST /10 AM
Saturday ORZ063.
Winter Weather Advisory remains in effect until 10 AM PST
Saturday ORZ062-064.
Winter Weather Advisory in remains in effect until 4 PM PST
this afternoon 0RZ061.
&&
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SHORT TERM...JT
LONG TERM....JDS/WH
AVIATION.....JDSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
1205 PM MST FRI DEC 23 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1140 AM SNOW 1 S BOISE 43.59N 116.23W
12/23/2016 E1.5 INCH ADA ID NWS EMPLOYEE
1145 AM SNOW 3 SW BOISE 43.58N 116.27W
12/23/2016 M1.5 INCH ADA ID NWS EMPLOYEE
1200 PM SNOW 3 S BOISE 43.56N 116.23W
12/23/2016 M1.6 INCH ADA ID OFFICIAL NWS OBS
STORM TOTAL AS OF 1200 PM
&&
JSMITHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
308 PM MST FRI DEC 23 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1257 PM SNOW EAGLE 43.69N 116.36W
12/23/2016 E3.0 INCH ADA ID NEWSPAPER
STORM TOTAL AS OF 1230 PM.
0306 PM SNOW BOISE 43.61N 116.23W
12/23/2016 M3.2 INCH ADA ID NWS EMPLOYEE
STORM TOTAL AS OF 300 PM.
&&
JSMITHThe national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
The COOP observer at Halfway reported 8 inches of new snow and the Baker County EM reported 6 inches in Baker City.
The COOP observers at Owyhee Dam and Nyssa reported 5 to 6 inches of snow.
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: 672276, 671756.