A Pacific system brought rain and snow the region during the second week of January. Snow levels were relatively high for this time of year, with snow accumulating above 2000 feet in the Washington Cascade east slopes and above 3800 feet in the Blue mountains.
Every event with a place to put it; 1 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 Pacific system brought rain and snow the region during the second week of January. Snow levels were relatively high for this time of year, with snow accumulating above 2000 feet in the Washington Cascade east slopes and above 3800 feet in the Blue mountains.
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 Jan 10, 10:00 AM PST, 45 minutes earlier.
Area Forecast Discussion...Updated
National Weather Service Pendleton OR
1000 AM PST Wed Jan 10 2018
Updated AVIATION discussion
.SHORT TERM...Today and Tonight...The upper level trough from
yesterday has moved off to the east leaving us under a northwest
flow with a low amplitude ridge centered just offshore. There is a
little moisture coming over the top of the ridge which will produce
a few showers mainly over the higher terrain through the day. A
stronger shortwave will be approaching and trying to move over the
ridge on Thursday. Ahead of this system there will be a warm front
moving into the region mainly impacting the northern two-thirds of
the forecast area starting late tonight and into Thursday.
Highlights have been issued for areas of concern regarding snow and
wind. Some of these could be expanded later on.
&&
.AVIATION...18Z TAFs...Ceilings today 070-110 with few isolated snow
showers over the Blue Mountains and east slopes of Cascades and dry
elsewhere. Winds 5-10kt, except KPSC 12-16KT. Rain will overspread
the TAF sites late tonight as a warm front moves into the region.
Ceilings will lower to 030-060, except KDLS 015-025 after 07Z. Polan
&&
.PREVIOUS DISCUSSION... /issued 256 AM PST Wed Jan 10 2018/
SHORT TERM...Today through Friday. The upper level trough and its
associated cold front have moved into Idaho and out of the region.
Temperatures this afternoon will be about 3-7 degrees cooler than
yesterday with highs in the mid 30s to mid 40s. A northwest flow
through the day will bring isolated snow showers over the mountains.
Skies will remain mostly cloudy through the day.
A moist warm front with strong upper level support will spread
precipitation across the northern half of the forecast area tonight,
mainly north of Madras and north of Ukiah. Winds aloft will
increase significantly on Thursday, and mountain waves will likely
develop along the southern WA and northern OR Cascades. However, the
likelihood of strong winds will be associated with the cold front
itself. Both the GFS and NAM indicate 850mb winds around 65 knots
across south central WA and north central OR. Due to a lack of
isentropic descent, will anticipate wind gusts of 45-55 mph over
central and north central OR, the southern Blue Mtn Foothills, and
the Simcoe Highlands and will issue a wind advisory for these areas.
Confidence in stronger winds is not enough to warrant high wind
warnings. However, additional highlights for wind may be necessary
during the next shift.
A considerable amount of QPF is anticipated with this upstream front-
-0.5-1.0 inch over the northern Blues and the east slopes of the WA
Cascades and 0.25-0.5 inch elsewhere (less than 0.25 inch in the
John Day Basin and Ochoco-John Day Highlands). Cold air along the
east slopes of the WA Cascades may be deep enough for at least 18
hours tonight and Thursday for snow to accumulate above 2500 feet to
meet advisory criteria of around 4-7 inches before snow levels
increase to higher elevations. Another area of concern for snow
accumulations will be over the northern Blue Mountains. Snow levels
will increase with the warm front but lower behind the cold front.
Due to uncertainty in the snow levels, will issue a Winter Storm
Watch for elevations above 4500 feet.
Drier conditions will follow on Friday as an upper level ridge
strengthens over the Pacific NW. Wister
LONG TERM...Friday night through Tuesday. Upper level ridge will
build into the region Friday night and remain through the weekend.
This will result in a period of quiet weather with partly cloudy
skies. Models continue to show strengthening low level inversion
which will bring low clouds and fog to the Columbia basin and
valleys. The ridge will move off to the east Monday as the next
upper level trough and front approach the Pacific northwest.
Clouds will increase during the day with a chance of rain late over
the Cascades. Rain and mountain snow is likely Tue into Wed as this
system moves across the forecast area. Temperatures will remain
above normal through the period with highs in the 40s. Some lower
50s possible in central Oregon. No significant winds expected. 94
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 36 54 39 / 10 60 90 40
ALW 47 38 54 40 / 10 60 100 50
PSC 47 36 53 40 / 10 50 100 20
YKM 44 34 46 34 / 10 60 90 20
HRI 48 35 55 40 / 10 50 90 30
ELN 41 33 41 32 / 10 60 90 20
RDM 45 33 52 29 / 20 20 50 20
LGD 41 33 45 35 / 10 50 90 80
GCD 42 33 48 32 / 10 20 50 50
DLS 49 36 52 42 / 10 60 80 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 10 AM Thursday to 4 AM PST Friday for ORZ508-
510.
Winter Storm Watch from late tonight through late Thursday night
for ORZ502.
Wind Advisory from 10 AM to 10 PM PST Thursday for ORZ511.
WA...Wind Advisory from 10 AM Thursday to 4 AM PST Friday for WAZ521.
Winter Storm Watch from late tonight through late Thursday night
for WAZ030.
Winter Weather Advisory from 7 PM this evening to 7 PM PST
Thursday for WAZ520.
&&
91/99/85/94The national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
Measured snow accumulation of 12 inches at Easton in Kittitas county.
Measured snow accumulation of 11 inches at the Touchet SNOTEL, 3 miles NNW of Ski Bluewood in Columbia county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2018Every state in 2018This day in weather historyWarnings in Washington, January 2018
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: 734146, 734147.