With the help of cooler and wetter weather, fire suppression activities continued through December.
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.
With the help of cooler and wetter weather, fire suppression activities continued through December.
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 Nov 30, 8:34 PM PST, 3 hours 26 minutes earlier.
Area Forecast Discussion UPDATED
National Weather Service Portland OR
834 PM PST Mon Nov 30 2020
...UPDATED for evening aviation weather...
.SYNOPSIS...After decreasing showers today, high pressure will take
hold and likely bring a prolonged period of east winds near the
Gorge and dry weather are wide through the upcoming weekend. Away
from the Gorge, light winds and persistent inversions will likely
lead to stagnant air conditions with deteriorating air quality
possible.
&&
.SHORT TERM...Tonight through Thursday...Region is now on the
backside of the shortwave trough and associated cold front which
moved across the region earlier. Trailing showers are becoming more
and more sparse with each hour. Snow amounts in the Cascades have
totaled 3-5 inches since last night with maybe an inch possible
over the next several hours. Do not expect that snow in itself will
present additional travel difficulties. However, for the most of the
area (except the coast), clearing skies, cooling temperatures and
residual water on roadways may lead to black ice tonight.
Looking forward, high pressure builds over the region but there are
a couple issues. First, the 12Z model suite is in good agreement
indicating offshore low-level flow developing late Tuesday,
strengthening Tue night and peaking Wed. A general north to
northeast low-level flow pattern develops Tue morning, but shifts to
northeast to east by Tue evening. The 12Z NAM indicates a KTTD-KDLS
gradient of -6 mb 00Z Wed and peaking at -10.2 mb Wed morning.
Typically, the NAM has a tendency to end up 1 to 2 mb too weak with
the max gradient. This trend is most prevalent with a deeper east
flow layer, more in line with a synoptic downslope event vs. a pure
gap flow event. Based on local rules of thumb, a -10 mb KTTD-KDLS
gradient would produce max gusts to around 80 mph at Crown
Point/Vista House.
The 12Z HREF mean wind gust guidance indicates 50-55 mph gusts early
Tue evening in favored portions of Clark County, such as Camas and
Washougal. The 4km WRF-GFS time-height section for Troutdale shows
the main core of east wind extending to about 900 mb Tue night and
then being compressed below 950 mb by Wed afternoon. Not
anticipating the need for a high wind highlight for the west end of
the Gorge as 75 mph or greater gusts will be very localized,
primarily to areas near Crown Point/Vista House. However, a wind
advisory may be needed for portions of the north Willamette Valley
and east Vancouver metro on Wednesday. The east wind gradually
decreases and becomes more confined to the western Gorge Wednesday
afternoon through Thursday.
The second issue will be stagnant air developing away from the
Gorge. Persistent inversions, low sun angle, and relatively light
winds begin later Tuesday and seem likely to persist into the
weekend. Have issued the advisory for our inland Oregon zones and
will hold off on Washington citing partner preferences. The best
possibility for breaking the stagnant conditions would be from a
weak and dissipating front approaching the coast late Thursday.
.LONG TERM...Thursday night through Monday...There is some
uncertainty in the extended as the aforementioned dying front has the
ECMWF chasing it with a largely dry cut off low forming and sliding
across the region beginning Thursday night. It then meanders over
the inland northwest through Monday. The remaining models simply
bring the ridge back overhead with, maybe, another weak front Sunday.
Regardless, generally expect dry weather under cool conditions for
the remainder of the week and weekend. areas of fog and/or frost
will likely occur for most areas. Under a non-EC model solution,
would also expect stagnant air to continue into early next week.
/JBonk
&&
.AVIATION...Dry northwestly flow aloft will maintain variable high
clouds tonight into Tue. This flow also maintaining a 4500 to 5500
ft deck against the Cascades tonight. Rather tricky forecast, as
air mass is rather dry and cold, so most of the moisture will likely
freeze out as frost. But, will see pockets of fog, mainly closer to
the rivers. So, will maintain some fog for KHIO, back towards KMMV
to KCVO down to KEUG, as well as in the Cowlitz River Valley. Any
fog will burn out rather quickly Tue am, likely by 18Z.
For detailed regional Pac NW weather information, go online to:
http://weather.gov/zse
KPDX AND APPROACHES...Mostly VFR tonight, but will likely see areas
of fog downriver from KVUO westward to KSPB tonight into Tue am, as
well as around the far south and west side of Portland metro
overnight. Any fog/stratus will be shallow, with tops 800 to 1000
ft. VFR on Tue, with light to moderate east wind Tue afternoon.
/Rockey.
&&
.MARINE...Wind speeds over the waters continue to diminish early
this afternoon. The 12Z NAM and GFS suggest wind speeds fall to
15 kt or less by late afternoon. The wind pattern becomes north
to northeast overnight and then veer to east Tue. Offshore flow
then persists through late in the week. The peak period will be
Wed, with gusts to 25 kt likely over the north waters and gaps in
the coastal terrain.
At 21Z seas were generally around 15 ft, although buoy 46248,
Astoria Canyon, reported 17 ft. In general, model spectral
guidance continues to be 2 to 3 ft higher than observed. Seas will
remain above 10 ft through around 18Z Tue and have adjusted the
Small Craft Advisory hazard to cover this. ENP and Gerling-Hanson
plot for buoy 46029 show a 23-25 second extra-long period swell
train beginning Tue morning. This eventually becomes the dominant
swell by late Tue afternoon, with periods around 20 seconds.
Thus, there will be a mix of 14 second west swell and a 20 second
northwest swell. Wave heights look to fall below 10 ft Tue afternoon,
but rise above 10 ft Wed evening, peaking in the low teens Wed
morning. Weishaar
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Air Stagnation Advisory from 10 PM Tuesday to 10 AM PST
Saturday for Cascade Foothills in Lane County-Central
Coast Range of Western Oregon-Central Willamette Valley-
Coast Range of Northwest Oregon-Greater Portland Metro
Area-Lower Columbia-Northern Oregon Cascade Foothills-
South Willamette Valley.
WA...None.
PZ...Small Craft Advisory until 10 AM PST Tuesday for coastal waters
from Cape Shoalwater WA to Florence OR out 60 NM.
Small Craft Advisory until 7 PM PST Tuesday for Columbia River
Bar.
&&
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www.twitter.com/NWSPortland8 wildfire. Local standard time, as filed.
The Beachie Creek wildfire was declared under control on December 2nd.
The Beachie Creek wildfire was declared under control on December 2nd.
The Riverside wildfire as declared contained on December 3rd.
The Riverside wildfire as declared contained on December 3rd.
Fire suppression activities continued on the Holiday Farm wildfire in the cool and wet weather of December.
Fire suppression activities continued on the Holiday Farm wildfire in the cool and wet weather of December.
Fire suppression activities continued on the Holiday Farm wildfire in the cool and wet weather of December.
Fire suppression activities continued on the Holiday Farm wildfire in the cool and wet weather of December.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2020Every state in 2020This day in weather historyWarnings in Oregon, December 2020
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: 935891, 935892, 935893, 935894, 935895, 935896, 935897, 935898.