A major winter storm caused by a rapidly deepening bomb cyclone brought heavy snow and high winds to the area, creating blizzard-like conditions at times. The cyclone moved onshore near the Oregon/California border with central pressure near 971 mb and then moved east-northeast through the area.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 major winter storm caused by a rapidly deepening bomb cyclone brought heavy snow and high winds to the area, creating blizzard-like conditions at times. The cyclone moved onshore near the Oregon/California border with central pressure near 971 mb and then moved east-northeast through the area. Numerous accidents and road closures, including Interstate 5, were reported. Around 8000 customers lost power due to downed power lines. The surface pressure recorded in Medford was the second lowest ever recorded at that station.
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 26, 4:42 AM PST, 3 hours 18 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
442 AM PST Tue Nov 26 2019
.DISCUSSION...Models remain in good agreement with the
historically deep low moving onto the coast of Southern Oregon
this afternoon. Models continue to show a very deep low pressure
center around 973 mb when it hits the coast, this is lower than
the 975 mb low of the historic Nov 9-10 storm in 1975.
The low is expected to hit the coast near Brookings late this
afternoon, moving over northern Klamath and Lake counties a little
before sunrise Wednesday as it continues to weaken after moving
inland. Discussion on each weather element is below;
WIND...Low pressure will rapidly intensify today. The storm will
undergo bombogenesis, with the pressure lowering to around 973 mb
by 4 pm PST. This is a greater than 40 mb drop in just 24 hours.
A "bomb cyclone" is defined as a 24 mb drop in 24 hours, so this
one is almost double that and wind impacts will be felt across the
entire area.
What makes this storm unique is the trajectory that it will take
as it deepens and moves inland. Rather than a deepening system
moving from SW to NE inside 130W, which typically bring our
strongest coastal and inland wind storms in SW Oregon and northern
California (and onshore gradients ALL along the coast), this one
will be moving in from NW to SE as it moves inland this evening.
This will focus the core of the strongest winds (and onshore
gradient) for the headlands/beaches from Cape Blanco southward.
Winds in those places will likely gust in excess of 75 mph with
gusts in excess of 100 mph possible at exposed areas and
headlands. This is a dangerous storm and we don't want to downplay
the winds for areas farther north, but an easterly (offshore)
gradient usually results in the winds getting blocked somewhat by
the terrain. We are still expecting gusts of 45 to 55 mph at North
Bend, but that's the reason it should be somewhat lower there.
Inland, strong winds should spread inland this afternoon,
impacting the higher terrain first, but also the south-north
(Shasta), and southeast-northwest (Rogue) oriented valleys. The
pressure gradient on the guidance RDD-MFR continues to be 10-12mb.
Studies have shown that this strong of a gradient, combined with
an alignment of the strong (850mb) winds with the valleys, has
caused high winds in the Shasta, and also the Rogue Valley. Gusts
could be in the 60-70 mph range.
High wind warnings or wind advisories are in place for all areas and
can be viewed at NPWMFR. The low will move inland tonight and the
strong winds will end. -Spilde/Sven
SNOW...Light precipitation is moving in from the coast with snow
levels in the 1700 to 2700 foot range. This begins to present some
concern for travel for the higher elevations of the coastal
mountains, to include the Sexton Summit area on Interstate 5.
Precipitation will increase in intensity late morning through
the afternoon. Overall, model guidance suggests that snow levels
will change very little during this time period as ice loading
from precipitation aloft evaporatively cools the lower levels.
This will effectively off-set daytime solar surface heating. One
particularly tricky area will be those locations such as the Rogue
and Shasta valleys, where downslope warming is likely due to the
increasing southeast winds. As the afternoon wears on in those
areas, we expect snow levels to nudge into the 2kft to 2.5kft
range. However, meanwhile, as the rapidly deepening surface low
nears the coast, snow levels are likely to sink lower and
accumulations are likely to increase on the Sexton passes, to near
1700 feet.
Overall, the highest snowfall totals will be in the Mt. Shasta
area where 18 to 25 inches of snow could fall in a 24 hour
period. Additionally, Interstate 5 at Siskiyou Summit could around
a foot of snow during the same time frame. This snow with the
gusty winds could create some near white-out conditions on these
summits. This combination will also work to reduce visibilities
along all of the higher passes if not near "white-out" conditions.
This evening and tonight we expect snowfall impacts will rapidly
increase as the core of the low pressure system tracks along or
near the Oregon-California border. Snow levels in the 1.5kft to
2.5kft range are expected to fall to between 500 and 1500 feet
through Wednesday morning. Snowfall rates are expected to maximize
this evening as snow levels fall and the low translates eastward.
It is in this time frame that valley accumulations are expected
on the west side, mostly in the 1 to 4 inch range for valley
locations between 1kft and 2.5kft on the west side. Road surface
temperatures have dropped into the 30s over most of the region
inland, and below freezing already over Siskiyou Summit and in the
Mt Shasta area, and over the east side, and snow should stick
almost immediately in these areas, with the rest of the region not
taking long after that once heavier rates occur. BTL/Sven
&&
.AVIATION...For the 26/12Z TAFs...Northwest flow aloft will continue
to bring moist onshore flow, building showers at the coast, terrain
obscuration, and MVFR/IFR Cigs/Vis to areas along and west of the
Cascades tonight. Showers will be primarily focused on north and
west facing terrain and also in the Umpqua Valley/Coast where
showers are typically less inhibited by the terrain. Showers will be
much more sparse east of the Cascades and in northern California.
Lower IFR/LIFR Cigs west of the cascades in the Rogue valley and
Umpqua Basin are expected to lift as winds ramp up going into the
morning, ahead of an east moving low pressure center.
A major storm will then move in today bringing high winds,
rain and snow to the entire region. This will result in serious
impacts to aviation. The main impact will be the strong and gusty
winds. Winds will increase along the coast around 18z and then
spread inland during the afternoon and evening. Have included wind
shear at Klamath falls, mainly for speed rather than direction,
during the evening. Wind shear is marginal at Medford, Roseburg, and
North Bend because the direction will be fairly uniform from the SFC
to 2000ft, but there will still be noticeable speed differences from
the surface to aloft. Rain and snow will also cause widespread
ceilings/visibility reductions and total terrain obscuration. Cold
air will also move in causing low freezing levels of 1000-1500 ft
Tuesday night into Wednesday MSL west of the Cascades, which means
snow will likely reach some valley floors. -Spilde/Miles
&&
.MARINE...Updated 300 AM PST Tuesday, 25 November 2019... A Storm
Warning is in effect for the coastal waters into tonight as a
rapidly deepening, low pressure system moves into the area from
the northwest and rapidly intensifies. Due the track and rapid
intensification of this low, this storm system is expected to be
unprecedented in its strength and a similar low has not been
observed in 40+ years.
Before the storm arrives, high and steep seas will continue over the
waters into Tuesday morning.
Conditions will deteriorate rapidly late Tuesday morning and Tuesday
afternoon as the rapidly deepening low moves into the waters. Winds
will shift to south to southeast and rapidly increase as the low
center deepens and nears the coastal waters from the west. Peak south
to southeast winds are expected on Tuesday afternoon and into the
early evening. Winds will likely reach 45 to 60 kt with occasional
gusts to hurricane force. Very steep, dangerous and chaotic seas
will build, reaching 20 to 32 ft. Given the track of the low, moving
towards Cape Blanco and areas just to the south, expect the highest
seas to occur from Cape Blanco southward. However, very dangerous
seas and very strong winds will also affect waters north of Cape
Blanco. As the low moves onshore Tuesday evening along the south
Curry coast, expect strong north winds to develop over the waters
with winds reaching storm force. North winds will gradually lower
Tuesday night but remain at gale force. Very high and very steep
seas will continue through Tuesday night and into Wednesday.
Mariners should seek refuge or safe harbor and remain in port for
the duration of this event. This is an unprecedented storm, the
likes of which have not been seen in 40+ years.
On Wednesday, winds are expected to gradually decrease, lowering to
small craft levels during the morning. However seas will likely
remain high and steep to very steep Wednesday into early Thursday
morning. More noticeable improvement is expected later Thursday into
Friday night.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory from 10 AM this morning to 10 AM PST
Wednesday for ORZ029>031.
Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday for ORZ029>031.
Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
Wednesday below 2500 feet in the for ORZ024>026.
Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday above 2500 feet in the for ORZ023>026.
High Surf Advisory from 1 PM this afternoon to 10 AM PST
Wednesday for ORZ021-022.
Wind Advisory from 1 PM this afternoon to 1 AM PST Wednesday for
ORZ023-025.
High Wind Warning from 10 AM this morning to 1 AM PST Wednesday
for ORZ021-022.
Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
Wednesday above 1500 feet in the for ORZ021-022.
High Wind Warning from 1 PM this afternoon to 1 AM PST Wednesday
for ORZ024-026.
Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday for ORZ028.
Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
Wednesday above 1000 feet in the for ORZ023.
Winter Weather Advisory from 10 AM this morning to 10 AM PST
Wednesday for ORZ027-028.
CA...Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday for CAZ082-083.
Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
Wednesday above 1000 feet in the for CAZ080.
Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday above 2500 feet in the for CAZ080.
Winter Storm Warning from 10 AM this morning to 10 AM PST
Wednesday for CAZ081.
Winter Weather Advisory from 10 AM this morning to 10 AM PST
Wednesday for CAZ084-085.
Pacific Coastal Waters...Small Craft Advisory until 10 AM PST this morning for
PZZ350-356-370-376.
Storm Warning from 10 AM this morning to 7 AM PST Wednesday for
PZZ350-356-370-376.
Hazardous Seas Warning from 4 AM to 2 PM PST Wednesday for
PZZ350-356-370-376.
SBN/SBN/SBNThe national radar mosaic for the moment the first event began.
3 heavy snow, 2 blizzard. Local standard time, as filed.
The coop observer at Chiloquin reported 12.0 inches of snow in 24 hours ending at 27/0800 PST.
Oregon highway 138 was closed due to blizzard conditions from Toketee east to U.S. 97. Oregon highway 62 from Prospect north and Oregon 230 to Diamond Lake Junction were also closed due to blizzard conditions.
No road closures were reported, but with significant snow and very strong winds, blizzard conditions did develop in this zone. The Squaw Peak RAWS recorded gusts exceeding 74 mph continuously from 26/1640 PST until 26/2139 PST. The peak gust was 90 mph, recorded at 26/1839 PST.
A spotter 6ENE Lakeview reported 12.0 inches of snow in 24 hours ending on the morning of 11/27/19.
The coop observer at Prospect reported 8.0 inches of snow in 24 hours ending at 27/2000 PST. A spotter 5.4NNW Gold Hill 8.6 inches of snow in 24 hours ending at 27/0700 PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2019Every state in 2019This day in weather historyWarnings in Oregon, November 2019
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: 860543, 860233, 860235, 860237, 860236.