A low pressure system moving into western Canada brought strong winds to the south Washington coast. As the cold front approached the coast, southerly winds picked up, gusting to 60 to 65 mph before turning westerly and decreasing behind the front.
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 low pressure system moving into western Canada brought strong winds to the south Washington coast. As the cold front approached the coast, southerly winds picked up, gusting to 60 to 65 mph before turning westerly and decreasing behind the front.
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 11, 3:28 AM PST, 2 hours 8 minutes earlier.
Area Forecast Discussion
National Weather Service Portland OR
328 AM PST Tue Dec 11 2018
.SYNOPSIS...Today and tonight will be rainy as a warm front moves
across NW Oregon this morning, followed by a cold front this evening.
The next warm front stalls over Washington Wednesday and Thursday
keeping most of NW Oregon dry, but maintaining light steady rain for
SW Washington. A cold front will move across the region Friday and
Friday night. Another frontal system is expected for the weekend.
&&
.SHORT TERM...Today through Friday...Light rain ahead of an
approaching warm front is moving into SW Washington and NW Oregon
early this morning. Snow levels will rapidly rise this morning as the
warm front gets closer to the coast. The Astoria profiler shows the
snow level there increased around 1000 feet between midnight and 2
AM. Will keep an eye on the snow levels on the Troutdale Profiler
when the rain reaches there in the next couple of hours to make sure
that the snow levels do indeed rise, and that the forecast reflects
the observed rises. The snow levels should rise to just above the
Cascade passes as the rain reaches the Cascades this morning, then to
6000-7000 feet late this morning. This rapid rise of the snow levels
will minimize snow impacts for the Cascades. The snow levels will be
slightly lower for the south Washington Cascades this morning, and 1
to 3 inches of snow is possible at elevations near 4000 feet before
the warmest air arrives.
The warm front will move onshore late this morning. Gusty west winds
behind the front will help the rain become more orographic as the
trailing cold front spreads heavier rain into the region this
afternoon and evening. The coast, coast range, and the Cascade
foothills will likely measure 1 to 3 inches of rain from this morning
through late tonight, with around 0.75 inch of rain expected for the
interior valleys. Do not foresee any hydrologic concerns, but areas
with poor drainage will likely have some ponding issues. Gusty S-SW
winds can be expected through this evening with gusts up to 45 mph
expected near the beaches and the higher terrain and gusts up to 35
mph for the lower elevations.
Cold air will fill in behind the cold front late tonight and the snow
levels will lower to 3000-3500 feet by sunrise Wednesday morning.
Post-frontal showers will likely result in 2 to 5 inches of snow for
the Cascade passes Wednesday morning through early Wednesday
afternoon. Cool unstable air behind the cold front may provide enough
instability to support isolated thunderstorms near the coast late
tonight into early Wednesday morning. A building upper level ridge
will end showers quickly Wednesday afternoon, except for SW
Washington where another approaching warm front will likely continue
rain through Thursday.
The upper ridge will keep most of this next front north of the
Portland forecast area which is why the rain will be mostly limited
to SW Washington Wednesday night and Thursday. Snow levels should be
above the Cascade passes and limit snow concerns for the South
Washington Cascades. The front changes position very little Thursday
and rain chances will be confined to SW Washington and the coast. THe
warm front lifts north further into Washington Thursday night for a
brief break in rain before the cold front arrives Friday morning.
Friday will be another wet day for the region as the cold front
spreads widespread rain across the region. Gusty winds are expected
with this front similar to what we could see with today's front. ~TJ
.LONG TERM...No Changes. Previous discussion follows...Friday night
through Monday...The active weather pattern will continue well into
next week with a series of fronts moving across the region. There is
some uncertainty in the timing of frontal systems over the weekend
and into next week. At this point in time it looks like there will be
a relative break between systems early Saturday, then another front
moves through late Saturday night and Sunday. Yet another system
arrives sometime Monday into Tuesday bringing more valley rain and
high elevation snow. tw/TJ
&&
.AVIATION...Broad atmospheric lifting, associated with an
approaching warm front, has returned conditions to VFR across
the region at this hour. Will see cigs lower to MVFR beginning
shortly at the coast and closer to 18z inland. Will see cigs
deteriorate further as the affiliated cold front arrives. Expect
IFR cigs at the coast around 20z and maybe make it inland,
however, vsbys inland may be more of the limiting factor as rain
rates increase. Additionally, southerly winds will increase today
with gusts 35 to 45 kt at the coast and around 25 kt later this
afternoon. Post-frontal showers will keep conditions in place for
much of the remaining 24 hour period with improvement most
likely to begin somewhere near 12/04z at the coast and 12/07z
inland.
PDX AND APPROACHES...VFR cigs will lower and likely begin to
affect visual approaches by the end of the boxer arrivals. The
bulk of the morning arrivals will likely require extra spacing,
both from sub 040 cigs, but also from increasing southerly winds
aloft. Warm front passes across PDX between 16Z and 18Z Tue,
with flip to southerly winds with cigs lowering further reaching
020 to 030. Periods of lowering vsbys under increasing rain rates
might bring 2-3 SM, but more likely will remain 3-5 SM through
12/03z as a cold front moves away. Conds appear to improve
further reaching VFR near 12/08z as showers decrease in coverage.
/JBonk
&&
.MARINE...Minor changes as models remain in decent agreement.
Generally, will see gusts in 30 to 40 kt range as a cold front
approaches today. Frequent post frontal wind gusts appear to
remain above gale criteria of 34 kt through a large part of
Wednesday so have extended the Gale warning through then.
Exception looks to be the central inner waters, but even then,
convective gusts may prove too frequent there as well. Models
continue to show a strengthening 972 MB surface low moving
northeast, but well northwest of the waters on Thursday. It does,
however, bring a cold front with stronger gales and possible
storm force gusts across the waters on Friday. No long term
break in sight as additional systems line up across the Pacific
well into next week.
Seas build reaching 14 to 17 ft tonight through Wed night.
Thereafter, details still need to be sorted out, but the overall
message is frequent and mixed swells will arrive to the waters
through early next week. The strong low on Thursday night/Friday
seems to be a more potent swell generator with combined seas
around 25 feet very plausible. Another round is possible later in
the weekend and could bring seas a little higher. Finally, some
models are bringing the strongest storm and highest seas
approaching 30 feet this time next week. Again, fully expect
details to change between now and then, but do want to portray
the overall message of poor conditions for the next several days.
/JBonk
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Gale Warning until 4 AM PST Wednesday for Coastal Waters from
Cape Shoalwater WA to Cascade Head OR out 60 NM.Waters
from Cascade Head to Florence OR from 10 to 60 NM.
Gale Warning until 4 PM PST this afternoon for Coastal waters
from Cascade Head to Florence OR out 10 NM.
Small Craft Advisory for Rough Columbia River Bar until 1 PM
PST Wednesday.
&&
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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.1 high wind. Local standard time, as filed.
Weather station at Cape Disappointment measured wind gusts up to 66 mph. Another weather station on Megler Bridge recorded sustained winds up to 47 mph.
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, 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: 798960.