An upper level shortwave and persistent moist northwest flow aloft continued to produce heavy snowfall across the northern Blue Mountains the afternoon of Monday Feb. 15th through the morning of Wednesday Feb.
Every event with a place to put it; 1 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 PDT wrote it up.
An upper level shortwave and persistent moist northwest flow aloft continued to produce heavy snowfall across the northern Blue Mountains the afternoon of Monday Feb. 15th through the morning of Wednesday Feb. 17th.
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 Feb 15, 1:57 PM PST, 2 hours 3 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
157 PM PST Mon Feb 15 2021
.SHORT TERM...Tonight through Wednesday night. Satellite showing
upper trough and short wave moving into Washington this afternoon.
Clouds and precipitation increasing. This system will move across
the forecast area during the evening and overnight. Moderate to
heavy snow likely for the Cascades and Blues with strong upslope
flow. Light precipitation for the Columbia basin into central
Oregon. Wide range of temperatures as some locations have warmed
up with breaks of sunshine and winds. Expect a mix of precipitation
into the evening then cooling airmass should switch over to mostly
snow. The short wave exits the area early Tue however northwest
upslope flow will continue through the day with mountain snow.
Upper ridge builds in Tue night with snow ending and clearing
skies. The ridge will be over the region on Wed with partly cloudy
conditions. Gradual warming trend the next few days with high
temperatures in the 30s to mid 40s.
.LONG TERM...Thursday through Monday...Relief from precip will be
brief as a strong jet streak overhead will lead to snow and rain
chances Thursday night. This will coincide with warming, however, as
the ridge behind the jet will flatten out and usher more westerly
flow over the CWA. Snow levels will rise to above 2000 ft by
Thursday night except for the Yakima/Kittitas Valleys, WA Cascades,
and the NE mtns. Models a bit divided with precip type outside these
areas, with global guidance and NBM leaning towards snow to start
before transitioning to rain as the flow aloft becomes more
westerly. Won't have a better idea until guidance converges more,
but for now it looks like the aforementioned areas with low snow
levels could see another round of accumulating snowfall.
Ensemble guidance in good agreement for the weekend, with a
transitory ridge overhead Friday before another trough arrives
Saturday night into Sunday. This system looks to be more all rain
outside of the crests of the Cascades and NE mtns, as strong
westerly flow aloft associated with the ridge will shoot snow levels
up above 4000 ft for most of the forecast area. Heading into next
week, models hinting at more ridging and thus more warming, however
ensemble members still a bit divided on the amplitude of the ridge
as it passes over the PacNW by Monday.
&&
.AVIATION...00z TAFs...Gradual clearing has been observed along the
foothills of the Cascades while low to midlevel cigs prevail at
other sites. Expecting this trend to continue as NW flow aloft
prevails, drying out BDN/RDM/YKM/DLS a bit more while colder air
remains trapped in the low levels at PDT/ALW/PSC through the period.
Cigs will lift a bit overnight for the latter sites, and are
expected to remain VFR or near MVFR through the evening. Slight
chance of precip between 00z-08z as a weak disturbance passes
through, however bulk of precip expected to remain in the mtns.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 39 27 38 / 60 40 20 10
ALW 27 39 28 39 / 60 40 20 10
PSC 25 41 24 41 / 30 10 10 0
YKM 22 43 21 44 / 40 10 10 0
HRI 29 43 27 43 / 40 10 10 0
ELN 22 39 23 41 / 50 10 10 0
RDM 27 41 20 41 / 40 20 10 0
LGD 30 38 26 37 / 80 70 40 20
GCD 27 37 24 36 / 70 40 20 10
DLS 32 45 31 47 / 60 40 20 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until 4 PM PST Tuesday for ORZ049-050-
502-503.
Winter Weather Advisory until 1 PM PST Tuesday for ORZ509.
WA...Winter Weather Advisory until 4 PM PST Tuesday for WAZ030.
Winter Weather Advisory until 1 PM PST Tuesday for WAZ520.
&&
SHORT TERM...94
LONG TERM....74
AVIATION...74PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1002 AM PST MON FEB 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0815 AM HEAVY SNOW NE HERMISTON 45.83N 119.28W
02/15/2021 M4.0 INCH UMATILLA OR PUBLIC
4 INCHES OF NEW SNOW, WITH 11 TOTAL ON THE GROUND. REPORT
VIA SOCIAL MEDIA.
0815 AM HEAVY SNOW 10 SW PENDLETON 45.57N 118.96W
02/15/2021 M7.2 INCH UMATILLA OR CO-OP OBSERVER
COOP OBSERVER RECORDED 7.2 INCHES IN 24 HOURS. CURRENTLY
14 INCHES OF SNOW DEPTH AND A 4 DAY TOTAL OF 20.5 INCHES.
1002 AM HEAVY SNOW PENDLETON 45.67N 118.82W
02/15/2021 M8.0 INCH UMATILLA OR OFFICIAL NWS OBS
NWS PENDLETON OFFICE RECORDED 8 INCHES OF NEW SNOW WITH
15 INCHES OF SNOW DEPTH.
&&
RBROOKSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1024 AM PST MON FEB 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0702 AM HEAVY SNOW ATHENA 45.81N 118.49W
02/15/2021 M7.0 INCH UMATILLA OR PUBLIC
REPORT OF 7 INCHES OF NEW SNOW IN ATHENA VIA FACEBOOK.
1000 AM HEAVY SNOW 9 SW SKI BLUEWOOD 45.98N 117.94W
02/15/2021 M11.0 INCH WALLOWA OR MESONET
MILKSHAKES SNOTEL RECORDED 11 INCHES OF SNOW ACCUMULATION
IN 24 HOURS.
&&
RBROOKSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1039 AM PST MON FEB 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM HEAVY SNOW 5 SSW SPOUT SPRINGS 45.69N 118.10W
02/15/2021 M11.0 INCH UMATILLA OR MESONET
HIGH RIDGE SNOTEL RECORDED 11 INCHES OF NEW SNOW IN 24
HOURS.
&&
RBROOKSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1202 PM PST MON FEB 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM HEAVY SNOW 2 SE DAYTON 46.30N 117.95W
02/15/2021 M6.5 INCH COLUMBIA WA CO-OP OBSERVER
COCORAHS OBSERVER RECORDED 6.5 INCHES OF NEW SNOW
ACCUMULATION IN 24 HOURS.
&&
RBROOKSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
139 PM PST MON FEB 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM HEAVY SNOW 12 SSE CANYON CITY 44.23N 118.86W
02/15/2021 M5.8 INCH GRANT OR COCORAHS
COCORAHS OBSERVER REPORTED 5.8 INCHES OF SNOW OVER THE
PAST 24 HOURS.
0700 AM HEAVY SNOW 7 NE WHITE SALMON 45.80N 121.38W
02/15/2021 M4.6 INCH KLICKITAT WA COCORAHS
COCORAHS OBSERVER REPORTED 4.6 INCHES OF SNOW IN 24
HOURS.
0700 AM HEAVY SNOW 4 ENE WHITE SALMON 45.75N 121.41W
02/15/2021 M5.4 INCH KLICKITAT WA COCORAHS
COCORAHS OBSERVER REPORTED 5.4 INCHES OF SNOW
ACCUMULATION IN 24 HOURS.
0700 AM HEAVY SNOW WNW WHITE SALMON 45.73N 121.48W
02/15/2021 M4.5 INCH KLICKITAT WA COCORAHS
COCORAHS OBSERVER REPORTED 4.5 INCHS OF SNOW ACCUMULATION
IN 24 HOURS.
0700 AM HEAVY SNOW 2 SSE SNOQUALMIE PASS 47.39N 121.39W
02/15/2021 M10.0 INCH KITTITAS WA COCORAHS
COCORAHS OBSERVER RECORDED 10 INCH OF SNOW.
0700 AM HEAVY SNOW 9 N ELGIN 45.69N 117.92W
02/15/2021 M10.0 INCH UNION OR COCORAHS
COCORAHS OBSERVER RECORDED 10 INCHES OF SNOW IN 24 HOURS.
&&
RBROOKSThe national radar mosaic for the moment the first event began.
1 heavy snow. Local standard time, as filed.
The High Ridge SNOTEL measured 11 inches of new snow between 4pm PST on Feb. 15th and 3am PST on Feb. 16th. A broadcast media report originating from 16 miles SE of Mission, OR reported 10 inches of new snow at 630am PST on Feb. 16th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2021Every state in 2021This day in weather historyWarnings in Oregon, February 2021
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: 938483.