Isolated severe storms produced damaging winds over central and north central Oregon during the late afternoon and evening of August 17, 2020.
Every event with a place to put it. 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 PDT wrote it up.
Isolated severe storms produced damaging winds over central and north central Oregon during the late afternoon and evening of August 17, 2020.
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 Pendleton, OR wrote its last area forecast discussion before the first event at Aug 17, 3:00 PM PST, 30 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
400 PM PDT Mon Aug 17 2020
.updated aviation discussion
.SHORT TERM...Tonight through Wednesday night...A ridge of
high pressure over the Great Basin extending up into the northern
Rockies and Pacific Northwest will slowly move to the east over the
next couple of days as an upper level trough off the coast moves
closer to shore. This will place the forecast area under a southwest
flow with some monsoon moisture caught in the flow passing over
eastern Oregon. This will lead to some showers and thunderstorms
overnight and again on Tuesday mainly from central Oregon up through
extreme southeast Washington. Some of these storms could be strong
to severe as they can produce wind gusts of around 60 mph.
Convection will shift a little further east on Tuesday and then just
some lingering storms possible Wednesday mainly over the Elkhorn and
Wallowa mountains. Otherwise, the approaching upper level trough
will begin to push cooler marine air over the Cascades late Tuesday
and Wednesday which will cool temperatures and place the rest of the
forecast area under a stable, breezy pattern especially along the
east slopes of the Cascades by Wednesday.
.LONG TERM...Thursday through Monday...The upper level trough will
flatten the upper level ridge and suppress the convective moisture
to the south of the region through the extended. A dominate westerly
flow will become established which will place the region under a
breezy westerly pattern with temperatures running around normal.
&&
.AVIATION...00Z TAFs...VFR conditions are expected through the
period. However, there will be showers and thunderstorms from
central Oregon northeastward through southeast Washington. This will
mainly impact RDM and BDN but could be in the vicinity of PDT and
ALW with gusty winds and brief rainfall and small hail. Winds are
expected to remain around 10kts or less other than the potential for
gusty outflow winds from the thunderstorms of 40 to 60 mph.
&&
.FIRE WEATHER...Red Flag warnings continue due to the potential for
fire starts from lightning through Tuesday evening. Will also begin
to see some locally breezy conditions along the east slopes of the
Cascades on Tuesday and Wednesday as marine air begins pushing
through the Cascade gaps and Columbia River Gorge.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 73 97 65 92 / 30 20 10 0
ALW 73 99 65 94 / 20 20 10 0
PSC 73 102 66 96 / 10 10 0 0
YKM 65 99 60 93 / 0 10 0 0
HRI 72 100 67 95 / 20 10 10 0
ELN 63 95 59 90 / 0 10 0 0
RDM 63 94 54 90 / 20 20 10 0
LGD 66 95 62 89 / 30 30 30 20
GCD 68 98 63 92 / 30 30 30 10
DLS 71 94 65 91 / 10 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Excessive Heat Warning until 9 PM PDT Tuesday for ORZ041-044-505-
507-508.
Heat Advisory until 9 PM PDT Tuesday for ORZ049-050-502-503-510-
511.
Red Flag Warning until 11 PM PDT Tuesday for ORZ611-640-642>645.
WA...Excessive Heat Warning until 9 PM PDT Tuesday for WAZ024-026>029-
521.
Heat Advisory until 9 PM PDT Tuesday for WAZ030-520.
&&
SHORT TERM...91
LONG TERM....91
AVIATION...91The Portland,OR radar (KRTX), 179 km away, was scanning. The volume nearest the first event began at 23:27 UTC.
5 thunderstorm wind. Local standard time, as filed.
Report by spotter of downed powerlines along highway 26 between Warm Springs and Madras.
Trees down and neighbor lost porch.
Power poles reported down.
Roof torn off carport in the Wolf Creek subdivision north of Warm Springs.
Tree down across route 74 at Ella Road.
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, August 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: 903049, 903051, 903054, 903173, 903058.