A strong northerly pressure gradient after the passage of an artic frontal boundary facilitated a period of extremely cold to hazardous wind chills, focused the evening of December 21st through the morning of the 22nd.
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 PDT wrote it up.
A strong northerly pressure gradient after the passage of an artic frontal boundary facilitated a period of extremely cold to hazardous wind chills, focused the evening of December 21st through the morning of the 22nd.
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 21, 2:32 PM PST, 1 hour 28 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
232 PM PST Wed Dec 21 2022
.SHORT TERM...Tonight through Saturday...A ridge of high pressure
will move over the region overnight and early Thursday for a dry
but very cold period. Overnight lows will range from minus 10 below
zero up to 10 above zero. Not record cold but still well below
normal for this time of year. A weakening shortwave will begin
passing through the ridge late Thursday bringing some precipitation
into central Oregon then spread across the rest of the forecast area
overnight. Precipitation type will start off as snow but some warm
air aloft will begin spreading over the region transitioning precip
type over to sleet and freezing rain. This will begin in central
Oregon late Thursday night and then spread north across the forecast
area on Friday. The cold air near the surface will be slow to erode
away but central Oregon will change over to rain Friday morning to
midday. The cold air will be deeper and harder to erode away across
north central Oregon and areas northward so expect freezing rain to
persist into Friday night before decreasing. Main concern with this
system will be the snow followed by the ice accumulations due to
freezing rain. Snow and ice accumulations amounts are generally
expected to be near to low end advisory amounts. However, a second
weather system is expected to move into the region Saturday with
higher QPF amounts in what will generally be a freezing rain event
around the Columbia Basin due to the cold air remaining trapped. The
highest ice accumulations are expected along the east slopes of the
Cascades from about the Madras area northward and especially around
the Columbia Gorge region. As such, Winter Storm Watches have been
issued through Saturday night. The Saturday system will bring
widespread freezing rain to the Columbia Basin region too but only
thinking advisory amounts at this time or around a tenth to two
tenths of an inch of an inch but higher amounts across north central
Oregon and northward along the east slopes of the Cascades.
.
.LONG TERM...Sunday through Wednesday...The overall ridge pattern
will shift the main track of precipitation northward Sunday but
continue to clip the forecast area will some precipitation. Most of
the cold air at the surface will have retreated north of the Horse
Heaven Hills meaning precipitation will be mainly rain except for a
possible wintry mix in the north. Ensemble models keep the overall
position of the ridge in place Monday into Tuesday before it moves
off to the east ahead of an incoming upper level trough. First of
the week will be warm with high snow levels and some possible
lingering freezing rain from the Tri-cities area northward Monday.
By Tuesday models are warming temperatures to above freezing in the
upper Basin region ending the freezing rain threat. The incoming
trough late Tuesday into Wednesday will lower snow levels bringing
snow to the mountains but rain to elevations below 3000 to 4000
feet.
&&
.AVIATION...00z TAFs...Expecting primarily VFR conditions through
the period, as cigs have lifted this afternoon with the colder air
surging into the region. May see some light snow in ALW/PDT/YKM in
light of the amplified flow aloft, but impacts are expected to be
limited to only intermittent reductions down to MVFR or IFR.
Otherwise ovc cigs in the area should become sct-few overnight, with
any precip expected with the next oncoming system to hold off until
after the period. Winds less than 10 kts for all sites except PSC
and DLS, which could gust up to 20 kts at times through the early
evening. Evans/74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 0 7 4 20 / 0 10 70 80
ALW -2 8 5 21 / 0 0 70 80
PSC -2 9 7 16 / 0 10 60 80
YKM -6 8 2 15 / 0 10 50 80
HRI 1 9 5 19 / 0 10 70 80
ELN -12 4 0 15 / 0 10 40 80
RDM 4 14 7 39 / 0 30 90 60
LGD 1 18 11 29 / 0 0 60 80
GCD 6 25 16 37 / 0 10 80 70
DLS 6 12 7 23 / 0 10 90 90
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Chill Advisory from 10 PM this evening to 10 AM PST Friday
for ORZ041-044-049-050-505-507-508-510-511.
Winter Storm Watch from Thursday afternoon through late Saturday
night for ORZ041-510.
Winter Storm Watch from Thursday afternoon through late Saturday
night for ORZ509.
WA...Wind Chill Advisory from 10 PM this evening to 10 AM PST Friday
for WAZ024-026>029-521.
Winter Storm Watch from Thursday afternoon through late Saturday
night for WAZ024-520-521.
&&
SHORT TERM...91
LONG TERM....91
AVIATION...91The national radar mosaic for the moment the first event began.
2 extreme cold/wind chill. Local standard time, as filed.
The ASOS station KELN recorded wind chill values at or below -20 degrees from 6pm December 21st to 2am December 22nd, and the Mesonet station TRYEG recorded wind chill values at or below -20 degrees from 12AM to 3AM on December 22nd.
The Mesonet station THORS recorded wind chill values at or below -20 degrees from 2AM to 11AM December 22nd and the Mesonet station AV456 recorded wind chill values at or below -20 degrees from 4AM to 11AM December 22nd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2022Every state in 2022This day in weather historyWarnings in Washington, December 2022
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: 1068277, 1068279.