A strong low pressure system tracked northeast into British Columbia. The associated cold front brought with it strong southerly winds on the north and central Oregon coast.
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.
A strong low pressure system tracked northeast into British Columbia. The associated cold front brought with it strong southerly winds on the north and central Oregon coast. This system also brought windy conditions to the Willamette Valley, bringing down tree limbs and a few trees, which caused scattered power outages.
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 Dec 14, 4:03 AM PST, 5 hours 17 minutes earlier.
Area Forecast Discussion
National Weather Service Portland OR
403 AM PST Fri Dec 14 2018
.SYNOPSIS...Complex low pressure and frontal system offshore will
move across the Pacific Northwest today, bringing a period of gusty
winds, rain, and high elevation snow. Post-frontal showers will taper
off quickly tonight, with some clearing and patchy valley fog by
Saturday morning. After a mostly dry Saturday, rain will likely
increase across the forecast area Saturday night and Sunday, with
snow levels rising well above the Cascade passes. Yet another system
is expected Monday night into Wednesday. This system appears to have
deeper moisture associated with it, bringing the possibility of heavy
rain and some river flooding concerns.
&&
.SHORT TERM...Today through Sunday...Challenging forecast today, with
a complex and evolving low pressure/frontal system approaching the
Pacific Northwest coast. Satellite imagery shows an elongated low
pressure system centered near 49N/130W, racing N-NE toward the
northern tip of Vancouver Island or perhaps further north. The low
center passed close to Buoy 46005, which recorded a minimum pressure
of 984 mb at 08z. This low appears to be starting to occlude, thus
likely has reached its prime over the past 1-3 hours. A cold front
connects this system to what appears to be a nascent low pressure
system in the vicinity of 39N/130W. Thus far, this system has failed
to develop as rapidly as some of the more aggressive models
suggested, which leaves our forecast in fairly good shape for the
time being. Will still need to monitor this southern system very
closely, as there is plenty of baroclinicity and jet energy in play,
and whatever results from it will likely move onshore in the vicinity
of the S WA coast this afternoon.
Pressure gradients are almost due easterly along the coast, which is
resulting in some impressively low dewpoints in the 20s for many of
our coastal observation sites. The dry air is resulting in coastal
temps well into the 50s at this early morning hour and steeper
low-level lapse rates, which is allowing for some localized gustiness
to the winds along the coast despite the easterly gradients. However,
the stronger winds associated with the front will likely hold off
until mid-morning along the coast, as the main core of 65-75 kt winds
at 925 mb and above moves through and MSLP gradients turn southerly.
The most likely period of strong winds for the coast appears to be
during the midday hours, so we will push back the start time of the
High Wind Warning for all our beaches and coastal headlands to 8 AM.
This system will also cause breezy conditions inland this afternoon
as the secondary low moves onshore, resulting in more of a southerly
component to the MSLP gradient through the Willamette Valley. Some of
the more aggressive model runs, with a deeper low moving into
Washington this afternoon, suggested winds could approach advisory
criteria for the Willamette Valley. However, with the developing
southern low failing to develop quickly this morning, we will keep
winds a tad below advisory criteria inland, capping gusts around 40
mph for the Willamette Valley. Cannot rule out a few isolated power
outages inland from these winds, but 45+ mph gusts will probably be
few and far between for the interior lowlands of S WA/N OR.
With a layer of very dry air to work through, the initial band of
precipitation will likely go through a good bit of evaporation while
moving onshore. Thus expect mainly light precipitation initially
today, with more widespread precipitation developing this afternoon
as the air mass becomes saturated. The initial dry air mass will
probably lead to quick cooling of the column over the Cascades, with
snow levels likely to fall to the passes by sunset despite starting
off with a freezing level of 9000 ft per this morning's 12z Salem
sounding. Eventually, this will result in a few inches of snow in the
Cascades above 4000 feet, with amounts pushing advisory criteria
above 5000-5500 feet. Opted against a Winter Weather Advisory, but
there will be a few hours of decent snowfall for the Cascade passes
and above toward sunset and early this evening. Post-frontal valley
rain and mountain snow showers will diminish overnight. There may
even be enough clearing overnight for some valley fog to develop,
especially south of Portland.
Saturday looks mainly dry, as transitory high pressure moves across
the region. The break will be brief, with high clouds probably
increasing again ahead of our next frontal system during the
afternoon. This system starts off fairly strong west of 130W, but
begins to weaken and become more splitty while approaching the Pac NW
coast and moves further away from its Gulf of Alaska parent low.
Models show reasonable agreement that the front becomes re-energized
with increasing moisture while approaching the coast Sat night/Sun,
but the core of this moisture plume and associated dynamics appear to
be headed for northern California. Snow levels will likely be well
above the Cascade passes with this system.
By the way, the aforementioned Gulf of Alaska parent low looks very
impressive at the moment and has an excellent dynamic fetch for
building large and energetic swell aimed toward the Pac NW coast.
This swell should arrive Sunday. More discussion on this in the
marine section below. Weagle
.LONG TERM...Sunday night through Wednesday...No changes. Previous
discussion follows...The 12z GFS and 12z ECMWF remain in agreement
through the majority of the extended forecast. The models both show a
series of lows, training into the area from the Gulf of Alaska
starting on Sunday. In addition a W-SW upper level zonal flow looks
to develop into an atmospheric river pattern.
The combination of the training lows from the Gulf of Alaska, and
atmospheric river pattern originating from the sub-tropics will
bring a steady flow of precipitation into the area through
Wednesday.
The training lows look to impact the area on Sunday and Tuesday
respectfully. As those systems cross our forecast area we can expect
periods of heavy precipitation. Overall, temperatures will be warmer
than normal, as we look to remain on the warm side of these systems.
/42
&&
.AVIATION...Fairly predominant VFR conds at this hour with the
vast majority of the area clr blo 120. There are isolated
pockets where the thin cloud cover aloft has allowed very patchy
low cloud, or more likely, very shallow fog to develop. Daylight
should take care of these patches very quickly. Mild south to
southwesterly flow aloft ahead of an approaching front will
result in predominantly VFR conditions through 18z. A short
period of moderate rain, gusty southerly winds, and MVFR cigs
will likely accompany the frontal passage. This appears likely
to occur along the coast between 18-21z and 21 to 23z for the inland
TAF sites. Instability behind the front should allow most
locations to quickly bounce back up to predominantly VFR
conditions, but a few lingering showers will likely temporarily
reduce cigs to MVFR thresholds for short periods 15/00-06z.
PDX AND APPROACHES...Expect predominantly VFR conditions through
06z Saturday as mild southerly flow aloft gives way to a decently
strong frontal passage between 22z Friday and 02z Saturday.
There may be a period of MVFR conditions around frontal passage
along with a brief period of southerly wind gusts of 30 to 35
kt. Am expecting wind shear over the terminal late tonight
through early Friday afternoon with gusty easterly winds at the
surface and stronger southerly winds at 1000-2000 ft AGL.
JBonk/Neuman
&&
.MARINE...An active weather pattern will continue for the next
several days. Low pressure remains rather elusive to identify on
satellite but appears to have an elongated center and is located
well off the PacNW coast near 130W. Buoy 46005 took a direct hit
from the deepening low center and showed surface pressure of 984
mb, very similar to 06z model initializations. The surface low
will continue pushing NNE toward and across Vancouver island this
morning. It will, however, drag a moderately strong cold front
across the waters this morning. Expect winds to decrease somewhat
quickly behind the front. Fresh swell and a longer period
westerly swell will bring combined seas topping out in the 20 to
25 ft range beginning mid-day through this evening. seas fall
more abruptly Friday night into early Saturday.
The next storm system then looks to spread increasing south to
southeasterly winds across the waters Saturday afternoon into
Saturday night. The strongest winds will almost certainly be
across the far outer waters for much of this storm system.
However, a developing surface low pressure depicted to move
northward along a front offshore should help to allow Gale Force
winds of 35 to 45 kt to spread closer to the coast Sunday
afternoon or evening, but some uncertainty still exists. In
addition, models have been rather insistent a larger westerly
swell around 25 ft with a dominant period of 18-20 seconds will
impact the waters Sunday afternoon and evening. High surf and/or
coastal flooding are of concern with this large of and powerful
of a swell so will continue to monitor model wave guidance.
Models suggest a brief respite in the winds will occur Sunday
night before another front drops southeastward into the waters
and stalls Monday into Tuesday. Several waves riding along this
front will likely result in winds temporarily going up and down,
but additional rounds of at least Gale Force winds with seas once
again rising above 20 ft appear more than possible. JBonk/Neuman
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Warning from 8 AM this morning to 4 PM PST this
afternoon for Central Oregon Coast-North Oregon Coast.
High Surf Advisory from 9 AM this morning to 10 PM PST this
evening for Central Oregon Coast-North Oregon Coast.
WA...High Wind Warning from 8 AM this morning to 4 PM PST this
afternoon for South Washington Coast.
High Surf Advisory from 9 AM this morning to 10 PM PST this
evening for South Washington Coast.
PZ...Gale Warning until 6 PM PST this evening for Coastal Waters
from Cape Shoalwater WA to Cascade Head OR out 60 NM.
Gale Warning until 4 PM PST this afternoon for Coastal Waters
from Cascade Head OR to Florence OR out 60 NM.
Small Craft Advisory for Rough Columbia River Bar until 2 PM
PST Saturday.
&&
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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 forecast area.2 high wind, 2 strong wind. Local standard time, as filed.
Weather stations on Megler Bridge and Clatsop Spit both observed sustained winds up to 43 mph.
A weather station on Yaquina Bridge recorded wind gusts up to 71 mph. A Florence C-MAN station also recorded sustained winds up to 43 mph.
Weather stations across the southern Willamette Valley recorded wind gusts up to 35 to 45 mph. The strongest was at the Eugene Airport, which recorded wind gusts up to 45 mph. Winds caused a tree to fall in Eugene, barely missing a woman who had just moved her new car out of the driveway where the tree fell.
Weather stations across the Portland metro generally reported wind gusts up to 35 to 45 mph. One weather station at Jantzen Beach reported wind gusts up to 52 mph. At least 4900 people were without power, according to PGE and Pacific Power due to downed limbs and a few downed trees on power lines.
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, December 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: 798979, 798980, 798996, 798995.