Cold low pressure system brought snow levels down near the Valley Floor. Though temperatures at the Valley Floor were a bit too warm for much accumulating snow, up in the Coast Range and Cascade Foothills, snow accumulated quickly with amounts generally around 5 to 10 inches.
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 PQR wrote it up.
Cold low pressure system brought snow levels down near the Valley Floor. Though temperatures at the Valley Floor were a bit too warm for much accumulating snow, up in the Coast Range and Cascade Foothills, snow accumulated quickly with amounts generally around 5 to 10 inches.
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 Portland, OR wrote its last area forecast discussion before the first event at Feb 18, 3:03 AM PST, 2 hours 57 minutes earlier.
Area Forecast Discussion
National Weather Service Portland OR
303 AM PST Sun Feb 18 2018
.SYNOPSIS...A cold upper low crossing the region today and
early tonight will bring colder air back into the region, as well as
some snow, potentially down to the valley floors by this evening.
The cold air mass will onlylinger through much of the week, slowly
recede from the region this week. A couple of upper level through
disturbances will bring additional chances for low elevation snow or
rain in the mid to late week.
&&
.SHORT TERM...Today through Tuesday...The upper low seen in water
vapor pictures along the coast of Vancouver Island early this
morning is expected to swing se across WA today, with a weak surface
low moving inland over sw WA. Air mass will cool today with the
upper low moving down, but then the coldest air will arrive tonight
with the passage of the upper low and the turning of low level winds
to the north. Air mass will be showery, aided by orographics with
the onshore flow. Lightning data has shown isolated strikes on the
west side of the upper low over the ocean. Models suggest deep
enough instability early today along and off the coast to include a
slight chance for thuderstorms, especially considering the cold air
mass moving down over sea surface temps on the order of 50F. As for
snow potential today into tonight, snow levels expected to remain
generally in the range of 500 to 1000 feet today, with lowest
elevation temps likely not to change much from the upper 30s to
around 40 values observed early this morning. This should seriously
restrict the areal coverage of any potential sticking snow today in
the low elevation zones west of the Cascades. Will keep the winter
weather advisories for the Lower Columbia and I-5 corridor and the
Portland metro area mainly for elevations above 500 feet today, but
drop the advisories for the Central and South Willamette Valley and
along the coast. Will also convert the winter storm warnings for the
Cascades to winter weather advisories as the westerly flow at 850 mb
weakens today form a peak of 30 to 35 kt this morning. As the
coldier and drier air mass arrives tonight with the passage of the
main upper trough, showers will diminish overnight. Will cut off
most of the advisories during the evening as showers become more
scattered.
The coldest air mass of the winter settles in by Mon morning, and
lingers into Tue as model 850 mb temps generally bottom out between -
10C and -12C. May see some locations flirt with record lows both Mon
and Tue morning. A chance for snow showers lingers through Mon over
the Cascades on theback side of the upper trough, which slowly moves
east across ID. The next shortwave in the northerly flow aloft is
expected to drop down Tue, but with models showing most of the
energy focused offshore. Some models suggesting mid level moisture
able to spread inland with this system. Will add in some low pops
for light snow Tue, with the best chances along the coast, but of
course this still infers that dry weather remains the more likely
outcome for Tue.
.LONG TERM...No Changes. Previous discussion follows...Tuesday night
through Saturday...Expect the cold pattern to continue through the
middle portion of next week before some slight moderation in
temperatures later in the week. Forecast models continue to display
somewhat different scenarios with various disturbances moving near or
through the region and as such, confidence in the details
(specifically, precipitation) remains somewhat lower than normal
through the long term forecast period. The mean longwave pattern
remains consistent with an amplified upper ridge remaining over the
east-central Pacific and generally northerly flow across the Pacific
Northwest. Thus, the key factor will be determining if a more
northeasterly or northwesterly component to the flow pattern aloft
develops. Maintained some mention of PoPs late Wednesday and early
Thursday, but at this point expect the snow level to remain around
1,500 feet or so through this time period. Otherwise, below normal
temperatures and only occasional infusion of moisture can be expected
through next week. Cullen
&&
.AVIATION...Unstable showery air mass over the region today. A
low will slide south over western WA today, then slide southeast
over the south WA Cascades & far north OR Cascades this
afternoon. The associated trough axis will bring an increase in
shower activity this morning. VFR prevailing with some MVFR early
this morning but should see an increase in MVFR as the trough
axis moves through this morning, the return to mostly VFR later
in the afternoon and evening. Heavier showers may produce snow
along with low MVFR to IFR vis and cigs. Feel these will be
brief enough to not include in TAFs at this time. Lingering -SHSN
this evening as precipitation wanes. Mountains will remain
obscured through tonight.
PDX AND APPROACHES...VFR prevailing through about 17Z Sun then
increasing chances, 40-60 percent, of MVFR cigs through 00Z.
Brief low MVFR or IFR possible with -RA or -RASN during this
time. 20 percent chance of -SHSN this evening as cooler air
arrives. /mh
&&
.MARINE...Gales have spread into most of the waters this morning.
Seas are around 20 ft for the PZZ270/250 and 17 ft for
PZZ275/255. The surface low tracking south over western WA will
keep a tight gradient over the waters today. A trough axis will
swing across the northern waters this morning and bump up winds a
little so have upgraded the advisory for PZZ250 to a Gale Warning
for this morning. The other change is to extend the Gale Warning
and Small Craft Advisory several hours for PZZ275 and PZZ255
respectively. There are some model differences regarding the
location and track of the surface low. The NAM and ECMWF shift
the low center inland into SW Washington 18Z Sun while the GFS
keeps the low center closer to Cape Disappointment, but still
inland. In any event, wind speeds will begin to diminish later
today and tonight. Wind speeds fall below 15 kt by Mon.
Seas ramping up over the waters as mentioned above, looks like 20
to 24 feet most likely for the outer waters and around 20 feet
for the nearshore waters. The peak should occur around midday
into the afternoon. The core of the large seas remain well
offshore. ENP and ECMWF models have it at 27 to 30 ft. Seas will
subside from north to south later today and tonight. Expect seas
to be under 10 ft by 00Z Tue. /mh Weishaar
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until 10 PM PST this evening for
Central Coast Range of Western Oregon-Upper Hood River
Valley.
Winter Weather Advisory until 10 PM PST this evening for
Central Columbia River Gorge-Western Columbia River Gorge.
Winter Weather Advisory until midnight PST tonight for Cascade
Foothills in Lane County-Cascades in Lane County-Northern
Oregon Cascade Foothills-Northern Oregon Cascades.
Winter Weather Advisory until 6 PM PST this evening for Greater
Portland Metro Area.
Winter Weather Advisory until 6 PM PST this evening for Coast
Range of Northwest Oregon-Lower Columbia.
WA...Winter Weather Advisory until 10 PM PST this evening for
Central Columbia River Gorge-Western Columbia River Gorge.
Winter Weather Advisory until 6 PM PST this evening for Greater
Vancouver Area.
Winter Weather Advisory until 6 PM PST this evening for I-5
Corridor in Cowlitz County-South Washington Cascade
Foothills-Willapa Hills.
Winter Weather Advisory until 9 PM PST this evening for South
Washington Cascades.
PZ...Gale Warning until 10 PM PST this evening for Waters from Cape
Shoalwater WA to Cascade Head OR from 10 to 60 NM.
Gale Warning until 2 AM PST Monday for Waters from Cascade Head
to Florence OR from 10 to 60 NM.
Small Craft Advisory for Rough Columbia River Bar until 10 PM
PST this evening.
Gale Warning until 1 PM PST this afternoon for Coastal waters
from Cape Shoalwater WA to Cascade Head OR out 10 NM.
Small Craft Advisory for winds until 2 AM PST Monday for
Coastal waters from Cascade Head to Florence OR out 10 NM.
Small Craft Advisory for hazardous seas until 10 AM PST Monday
for Coastal waters from Cascade Head to Florence OR out 10
NM.
&&
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. This area is
commonly referred to as the CWA or forecast area.2 heavy snow. Local standard time, as filed.
ODOT weather stations recorded 6-7 inches of snow at summits through the Coast Range. Also had reports via Social Media and CoCoRaHS of 7-8.5 inches of snow near North Plains and on Dixie Mtn.
CoCoRaHS observer in Oakridge recorded 10.4 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2018Every state in 2018This day in weather historyWarnings in Oregon, February 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: 742315, 742317.