a very late first freeze for many locations.
Every event with a place to put it; 2 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.
Clearing skies and a cold air mass made for freezing temperatures over parts of southwest Oregon...a very late first freeze for many locations.
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 Dec 1, 8:51 PM PST, 4 hours 9 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
851 PM PST Thu Dec 1 2016
.DISCUSSION...The forecast was updated to increase coverage of
late night into early Friday morning valley low clouds. Also,
the probability of light rain was increased for the far northwest
and north central portion of our area Friday afternoon into
Saturday morning related to the warm front which will brush past
as it moves northwest to southeast while remaining mainly north
of our area. The probability will be highest late friday night.
&&
.AVIATION...02/00Z TAF cycle... Conditions are mainly VFR. However,
West Side valley fog developing late this evening into tonight and
continue into the morning. Expect areas of IFR/LIFR in western
valleys to develop between by 09z and persist through the morning
with gradual clearing in the late morning and early afternoon.
Coastal areas will also see areas of IFR develop overnight and early
in the morning, including at KOTH, with clearing to VFR in the late
morning. Confidence is low to moderate on the exact timing of IFR
formation and clearing. -CC
&&
.MARINE...Updated 225 PM PST, Thursday 1 December 2016...
High and steep west swell will continue through this evening before
subsiding below 10 feet. A few showers this morning will give way to
high pressure this evening through early Friday. Late Friday though
Saturday a weak frontal system will move through bringing shifting
winds and another round of building west swell. This swell is
expected to peak seas in the 14 to 17 foot 18 second range on
Saturday. A stronger front will move in Sunday with blustery
northwest winds and bringing continued steep hazardous seas behind
it, with steep seas persisting through at least Monday afternoon.
-CC
&&
.PREV DISCUSSION... /Issued 227 PM PST Thu Dec 1 2016/
DISCUSSION...A rather quiet pattern is in store for the next couple
of days as an upper ridge nudges into the area today. Low clouds
were hanging tough in the Rogue and Illinois Valley, but they are
breaking up and will end up partly cloudy later this afternoon.
Elsewhere we'll have mixed clouds and sun, except for mostly
cloudy skies in northern Klamath and all of Lake County. Clouds
will dissipate this evening with mostly clear skies tonight. This
along with a drier air mass will allow temperatures to drop below
freezing in the Rogue and Illinois Valley and a freeze warning
remains in effect. See NPWMFR for details. Despite the drying,
still could not rule out areas of fog and low clouds again for the
same areas that had it this morning. Meanwhile temperatures east
of the Cascades could drop to their lowest readings of the season
with readings in the mid to upper teens.
A warm front will move north of the area on Friday. The models have
backed off somewhat on the southward extent of the precipitation
which makes sense given 500mb heights are expected to rise as the
ridge axis builds into the area (although there is a subtle
flattening of the ridge later in the afternoon). Given the above
mentioned scenario, decided to back off on pops, especially south of
the Umpqua Divide and kept a slight chance to low end chance to the
north.
The ridge will flatten out some Friday night through Saturday, but
the bulk of the precipitation should still remain north of us. Still
could not rule out a few sprinkles north of the Umpqua Divide, but I
would not expect anything measurable.
The next item of concern is Sunday through Sunday night. The models
still show differences in the timing of the front, track of the
shortwave behind it and amount of available moisture behind the
front. For example the GFS pushes the front into our area late
Sunday morning with a quick shot of precipitation with the bulk of
the precipitation gone by the time the colder air moves overhead
Sunday evening and night, thus limiting the impact of low elevation
snow. On the flip side, the 12 EC is slower with the arrival of the
front by about 6 hours and shows more QPF behind the front Sunday
evening and night as the colder air moves in which if taken at face
value would mean a higher concern for lower elevation snow.
Either way, there's a chance the higher passes over the Cascades,
Siskiyou Summit have a good chance for accumulating road snow.
Sexton, Canyon, Stage Summit and highway 42 near Camas Mountain
could also get some road snow, but I'm less confident on this. It's
still a ways out, so there's plenty of time for some of the details
to come into better agreement.
If that weren't enough there's some evidence PVA within a cool
northwest flow could result in enhanced showers west of the Cascades
Monday through Monday night and could result in snow levels lowering
close to the valley floors in the Rogue and Illinois Valley. Again,
this is still a ways out, but the main takeaway from this is to stay
tuned for the latest updates and confidence should be higher as we
get closer. -Petrucelli
Extended...Tuesday through Friday. On Tuesday, precipitation will
begin clearing as slight ridging builds. Expect clearing to bring
valley fog in west side valleys Wednesday morning. A very cold dry
surface air mass will move into the forecast area, coming from the
northern Rockies. This will bring temperatures in the single digits
to teens on the east side, and in the twenties on the west side
Wednesday morning. During the second half of the week, we will
transition to a wet pattern. Models start to diverge somewhat during
the day Wednesday.
Both the GFS and EC depict a strong low pressure system in the Gulf
of Alaska driving a warm front over the CWA, bringing precipitation
to the area. However, the GFS is roughly 24 hours faster than the EC
in bringing in precipitation. Leaned towards the GFS for this
forecast, thus chances of precipitation increase Wednesday. With a
cold air mass in place, this could mean snow levels below 2000 feet.
Again, model uncertainty is high regarding the timing of the
precipitation. After the warm front passes over, the cold front
associated with this low will bring high winds to the east side,
possibly hitting hazard criteria. -MSC/FJB
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Warning from 1 AM to 9 AM PST Friday for ORZ024-026.
CA...None.
Pacific Coastal Waters...Small Craft Advisory for hazardous seas
until 10 PM PST this evening for PZZ350-356-370-376.
Small Craft Advisory for hazardous seas from 10 PM Friday to 2
PM PST Monday for PZZ350-356-376.
Small Craft Advisory for hazardous seas from 10 AM Friday to 2
PM PST Monday for PZZ370.
DW/MAP/CCThe national radar mosaic for the moment the first event began.
2 frost/freeze. Local standard time, as filed.
Reported low temperatures in this zone ranged from 29 to 32 degrees.
Reported low temperatures in this zone ranged from 27 to 35 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2016Every state in 2016This day in weather historyWarnings in Oregon, December 2016
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: 662085, 662086.