A strong low located in the Gulf of Alaska resulted in a building long period west-northwest swell with sneaker waves along the southern Oregon coast.
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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 MFR wrote it up.
A strong low located in the Gulf of Alaska resulted in a building long period west-northwest swell with sneaker waves along the southern Oregon coast.
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 Medford, OR wrote its last area forecast discussion before the first event at Nov 21, 3:44 AM PST, 2 hours 16 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
344 AM PST Tue Nov 21 2023
.DISCUSSION...Increasing cloud cover will help keep temperatures warmer
this morning. It will be a delight for many to step outside this
morning because temperatures will be in the upper 30s and low 40s
west side compared to the low 30s last night. For areas east of
the Cascades, northern Klamath County and southern Lake County
will see the best improvements with lows nearing the mid-20s with
isolated spots nearing 30 degrees. These lows will be comparable
for Wednesday morning as well. Tonight patchy fog has developed in
the Rogue and Umpqua Basins, and this will burn off through the
morning. Skies will turn to mostly clear through the day and upper
level ridging will allow us to enjoy another afternoon with
temperatures near 5 degrees warmer than normal for east side and 5
to 15 degrees warmer than normal for the Cascades and west.
The upper level ridging combined with lighter winds has led to poor
mixing and an air stagnation advisory is in effect until 10 PM this
evening. A front off the coast will move into Oregon in the middle
of the week which will help relieve these conditions. This front
will also bring precipitation chances to Coos County Tuesday night
and the front moves inland bringing the precipitation with it
Wednesday. Chances reach 40-60% Wednesday morning near and west of
the Cascades with increasing chances for east side later Wednesday.
Snow levels Wednesday night will fall to 4,500-5,500 feet, so some
snow will be possible in higher elevations. However, rainfall
amounts are likely to stay below the 0.25" mark, so this event will
not create much. An upper trough arrives later this week and will
bring colder temperatures to the area this weekend. -Hermansen
&&
.AVIATION...21/12Z TAFs...Fog and low stratus have returned to many
of the same valleys tonight. Gusty easterly winds leading to low
humidities on the ridges may mix down into the valleys and dry them
out, resulting in less fog or stratus. Calm winds were found at the
surface in the Rogue Valley and the balloon sounding showed 30 mph
SE winds 1,000-2,000 feet off the ground. This change brings the
potential for low level wind shear through 18Z. At other terminals,
dry easterly flow will maintain VFR.
Impacted conditions that do develop should clear later this morning,
and upper ridging will result in calm, variable winds.
-CSP/Hermansen
&&
.MARINE...Updated 230 AM Tuesday November 21, 2023...South winds
will increase today ahead of a cold front. Seas will become steep
and hazardous to small craft again for many areas. Winds will
shift to north behind the front Wednesday and seas will remain
steep. Strong, gusty north winds and steep to very steep seas are
then likely Wednesday night through Friday with strongest winds
and steepest seas south of Cape Blanco. Additionally, Thursday
afternoon through Friday, long period northwest swell will mix with
west swell and short period wind seas. -Spilde
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Air Stagnation Advisory until 10 PM PST this evening for
ORZ023>026-028>031.
CA...Air Stagnation Advisory until 10 PM PST this evening for
CAZ080>085.
PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM this morning
to 7 PM PST Wednesday for PZZ350-356-370-376.
Hazardous Seas Watch from Wednesday evening through late
Thursday night for PZZ370-376.
&&The national radar mosaic for the moment the first event began.
2 sneakerwave. Local standard time, as filed.
A strong low located in the Gulf of Alaska resulted in a building long period west-northwest swell with sneaker waves along the southern Oregon coast.
A strong low located in the Gulf of Alaska resulted in a building long period west-northwest swell with sneaker waves along the southern Oregon coast.
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, November 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: 1147671, 1147672.