A good moisture tap from a low off the coast of Oregon spread heavy snow and rain across parts of Southwest Idaho and Southeast Oregon over nearly a two day period.
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 good moisture tap from a low off the coast of Oregon spread heavy snow and rain across parts of Southwest Idaho and Southeast Oregon over nearly a two day period.
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 Jan 26, 8:45 PM MST, 5 hours 15 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
845 PM MST Tue Jan 26 2021
.DISCUSSION...Forecast remains on track with only minor updates
this evening. Satellite infrared imagery depicts colder cloud
tops, associated with the incoming storm system, pushing into
eastern Oregon. Radar echoes are also starting to increase across
eastern Oregon. Snow will begin across Oregon late this evening
and overnight and push into western Idaho early Wednesday morning.
Strong southwest flow aloft will result in significant downsloping
and drying in the lee of mountain barriers (such as the Owyhees)
as well as enhance precipitation on southwest-facing slopes. As a
result, snow amounts of less than an inch are expected across much
of the Snake River Valley Wednesday morning. However, areas such
as northern Harney and Malheur counties, the mountains of Baker
County, the Weiser River Basin, the Camas Prairie, and the
central Idaho mountains will receive moderate to heavy snow late
tonight through Wednesday afternoon. Winter Storm Warnings and
Advisories are in effect in these areas. Additionally, gusty south
to east winds will produce areas of blowing and drifting snow on
Wednesday. Precipitation will taper off Wednesday evening, but
additional mountain snow is expected on Thursday. Warmer valley
temperatures will result in valley rain or a rain-snow mix on
Thursday.
&&
.AVIATION...VFR with an increasing presence of MVFR/IFR due to
incoming snow. Snowfall to remain present through Wednesday
afternoon, with a few areas of central Idaho seeing activity linger
into Thursday. Mountain obscurations expected. Low-level wind shear
favored across many terminals with increasing upper-level winds.
Surface winds: East to southeast at 10 to 20 kts with gusts to 35
kts possible. Winds aloft near 10k feet MSL: Southwest 30-50 kt.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Thursday night...A potent winter
storm will move into eastern Oregon this evening and track into
southwest Idaho overnight. Heavy snow is forecast for much of the
higher terrain of the area, along with a few lower-elevation
areas. Winter storm warnings and advisories have been issued and
remain unchanged. Winds will increase tonight, with strong
southwest winds at higher elevations, and moderate southeast winds
in the Snake Plain and Baker Valley. Winds will be close to
advisory levels briefly late tomorrow morning, especially near
Mountain Home. Snowfall totals have not changed much from previous
forecasts, with generally 2 to 6 inches in lower elevations sites
that will see snow, such as the Weiser River Basin, and over a
foot in the mountains above 6000 ft. McCall is forecast to get
around 9 inches in the next 48 hours, with an additional 3 coming
Thursday night into Friday. The Treasure Valley may see light snow
tomorrow morning, but accumulations are expected to be less than
an inch, with only a dusting the most likely scenario. Temps will
not fall too much tonight, owing to increasing cloud cover and
winds. Temps Wed will not warm much due again to cloud cover, but
also to precipitation. The strong storm that is bringing this
winter system will still be off to our west Thursday night,
meaning southwesterly flow aloft will continue through the short
term. This will advect slightly warmer air into the area and raise
snow levels. Many folks will see light snow tomorrow, but then
will see light rain (or a rain/snow mix) by late Wed night into
Thursday.
LONG TERM...Friday through Tuesday...Active weather pattern will
continue through the extended period as a series of systems move
through the region. An upper-level trough and associated cold
front will move east through the Pacific Northwest on Friday. This
will lower temperatures slightly from previous days. Low elevation
rain and mountain snow will shift eastward with the front just as
snow levels lower to valley floors Friday evening. The upper
level flow turns back to the southwest with passage of a weak warm
front on Saturday for isolated snow showers. Southwest flow will
strengthen for Sunday and Monday, as rain and snow will returns
Monday with the next significant storm system. There remain vast
differences between the models on the track of the low system thus
confidence in precipitation remains low. The best chance for snow
will be the favored upslope mountain locations once again, and
breezy surface winds can be expected across the valleys.
Temperatures will start to rise again for Sunday and Monday,
roughly 5-10 degrees above normal through Tuesday.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 5 PM MST Wednesday IDZ013-033.
Winter Storm Warning until 5 PM MST Thursday IDZ028.
Winter Weather Advisory until 5 PM MST Wednesday IDZ011.
OR...Winter Storm Warning until 5 PM MST /4 PM PST/ Wednesday
ORZ062>064.
Winter Weather Advisory until 10 AM PST Wednesday ORZ061.
&&
www.weather.gov/Boise
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www.twitter.com/NWSBoise
DISCUSSION...ST
AVIATION.....KB
PREV SHORT TERM...SP
PREV LONG TERM....JSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
155 AM MST WED JAN 27 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0153 AM HEAVY SNOW 3 E BURNS 43.59N 119.00W
01/27/2021 M0.0 INCH HARNEY OR PUBLIC
4 INCHES REPORTERD BY A SPOTTER EAST OF BURNS OREGON
&&
CREDMANThe national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
Reports of 5 inches of new snow were received from Huntington and Durkee.
Reports of 4 to 5 inches of new snow were received from Juntura and Jamieson.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2021Every state in 2021This day in weather historyWarnings in Oregon, January 2021
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: 937033, 937036.