A southwesterly swell of 20 to 25 ft with a period of 17 seconds was observed across the coastal waters, resulting in a high threat of sneaker waves.
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 southwesterly swell of 20 to 25 ft with a period of 17 seconds was observed across the coastal waters, resulting in a high threat of sneaker waves.
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 28, 3:53 AM PST, 4 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service Portland OR
353 AM PST Thu Dec 28 2023
.SYNOPSIS...A series of storm systems will bring unsettled weather
with periods of rain and high mountain through Saturday. Sunday and
Monday appear most likely to be dry with a 50-60% chance for that dry
weather to last into Tuesday or Wednesday.
&&
.DISCUSSION...Today through Wednesday...Water vapor satellite imagery
early this morning reveals a low pressure moving northward toward
Haida Gwaii. An occluded front that brought rain to the region this
morning has shifted into the northern Rockies. Post frontal showers
and a couple thunderstorms along the coast continue to spread
northeastward into the region. Expect these showers to decrease and
lift northward as our flow turns more southerly ahead of the next
storm system.
Satellite imagery also shows another low pressure near 150W & 40N is
rounding the base of the larger scale shortwave trough. Global
ensemble members are in good agreement it will move towards the
Oregon Coast before lifting northward towards Vancouver Island/Haida
Gwaii Friday into early Saturday. As it does so, expect east to west
pressure gradient forces to increase once again across the Cascades.
This should rev up east winds through the Columbia River Gorge. NBM
guidance once again pushes the peak east wind gusts up to around
40-45 mph at KTTD on Friday. Another round of 60-70 mph gusts look on
tap for Corbett. This round of east winds will be really short lived
and primarily limited to late Thursday night and Friday. Global
ensemble guidance is in remarkably good agreement that high pressure
east of the Cascades will weaken substantially Friday night into
Saturday as the next front and round of light precipitation spread
eastward across the Pacific Northwest.
There is general support among the global ensembles for drier weather
to take hold Sunday into Monday across the area. However, it
certainly isn't guaranteed that it will come to fruition,
particularly along the coast. Nonetheless, NBM PoPs are quite low
during this period and and seem representative of raw ensemble
guidance.
More substantial differences among global ensemble guidance in the
large scale weather pattern appears to take shape as we move into
next Tuesday and Wednesday. The majority of ensemble guidance keeps
some shortwave ridging over the region, which results in a longer
stretch of dry weather for the region. However, about 30-40% of the
ensemble guidance suggests a shortwave trough and closed low will
move close enough to the region to bring light precipitation back to
the region. We certainly could have some spotty freezing rain in the
upper Hood River Valley in such a pattern or deal with some light
snow accumulations across the Cascades, but overall the weather
pattern appears quite benign for late Dec/early Jan. The probability
of a major weather event happening across most or all of the CWA in
the next week is near zero. /Neuman
&&
.AVIATION...Currently, predominately VFR conditions with MVFR
conditions along the coast and post-frontal showers throughout the
CWA. Light showers and VFR conditions expected throughout the TAF
period, with chances of MVFR cigs around 10-20% for most
terminals, beginning around 18z Thu. Breezy east winds will
persist near the mouth of the Columbia River Gorge, with gusts up
to 30 kts at KTTD.
PDX AND APPROACHES...VFR expected with light showers. East southeast
winds around 10-15 kt expected to persist through Thursday. -JH
&&
.MARINE...Gale Force winds are currently dying, thus have allowed
the Gale Wind warning to expire. However, seas have begun to rise
above 20 ft and will remain so until around 10am-12pm PST.
Another storm system will slide into the eastern Pacific Friday
into Friday night. This will keep winds elevated over the waters,
with a probability of Gale Force winds around 60-80% for early
Friday across the outer waters (beyond 50 nm). Seas will likely
climb back into the mid teens Friday night into Saturday. A
quieter weather pattern early next week is looking like it will
allow seas to drop below 10 ft.
-JH
&&
.BEACH HAZARDS...High surf will impact our coastline through at
least this morning as a southwesterly swell of 23-25 ft with a
dominant period of 17 seconds spreads northeastward across the
waters. Most model scenarios suggest this event will top out
within the upper range for High Surf Advisory criteria.
Nonetheless, there is a ~30% chance that the swell ends up several
feet higher and places us well within warning criteria and
impacts are greater along the coast. Either way, sneaker waves are
always a significant hazard during high surf events.
-JH
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory until 4 PM PST this afternoon for Central
Oregon Coast-North Oregon Coast.
WA...High Surf Advisory until 4 PM PST this afternoon for South
Washington Coast.
PZ...Gale Warning until 4 AM PST early this morning for Coastal
waters from Cape Shoalwater WA to Florence OR out 10
NM-Columbia River Bar-Coastal waters from Cape Shoalwater
WA to Florence OR from 10 to 60 NM.
Hazardous Seas Warning until 10 PM PST this evening for Columbia
River Bar.
Hazardous Seas Warning until 4 AM PST Friday for Coastal waters
from Cape Shoalwater WA to Florence OR out 60 NM.
&&
www.weather.gov/portland
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www.twitter.com/NWSPortland1 sneakerwave. Local standard time, as filed.
A southwesterly swell of 20 to 25 ft with a period of 17 seconds was observed across the coastal waters. A 5 year old girl was hospitalized after she was hit by a sneaker wave near South Jetty Beach in Florence, OR.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2023Every state in 2023This day in weather historyWarnings in Oregon, December 2023
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: 1154788.