An upper-level trough and strong cold front brought a round of heavy snow to the Pacific Northwest mountains February 25th through the night of February 26th.
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 trough and strong cold front brought a round of heavy snow to the Pacific Northwest mountains February 25th through the night of February 26th.
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 25, 2:53 PM PST, 4 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
253 PM PST Sun Feb 25 2024
.SHORT TERM...This afternoon through Tuesday night...An incoming
upper-level trough and robust cold front will facilitate active
winter weather across the PacNW through Tuesday night. Current
radar shows pre-frontal orographic returns (mostly rain below 4000
feet and rain/snow mix above) across the Cascade crest of
Washington and far northern Oregon with some light spillover along
the adjacent eastern slopes in Washington. To the east,
increasing reflectivity aloft from Pendleton north through
southeast Washington has yet to cut through the dry boundary layer
per surface observations. The main cold front will arrive along
the Cascade crest later this afternoon and progress southeastward
across the forecast area overnight into Monday morning. Snow
levels will lower significantly behind the front, such that light
low-elevation snow for population centers in central to northeast
Oregon and southeast Washington is forecast. Probabilities of
exceeding advisory criteria are too low (20% or less, except
20-50% along the elevated terrain above 1400-1600 feet of the
northern Blue Mountain foothills in the vicinity of Athena/Weston
and Dayton) to warrant the issuance of any winter weather
products with the afternoon forecast. Elsewhere, have issued
winter weather advisories for Wallowa County as well as the
southern Blue Mountains and the Ochoco-John Day Highlands for 10
PM this evening through 4 AM Tuesday as probabilities of low-end
advisory amounts are supportive (40-80% chance of 3-5", highest in
the river valleys of the Wallowa Mountains and above 4500 feet in
the southern Blues and Ochoco- John Day Highlands).
Winds aloft continue to increase as the upper-level trough sags
southeast into the PacNW. Have already seen gusts of 45-55 mph in
the Columbia Basin and along the Simcoe Highlands as of this
afternoon with wind advisories in effect through 3 PM Monday.
Probabilities of advisory-level gusts peak at 40-90% the
remainder of this afternoon through 10-11 PM, a combination of
pre-frontal winds this mixing to the surface this afternoon and
frontal winds this evening.
Post-frontal showers (snow for the mountains and a mix of rain and
snow for the lower elevations) are forecast Monday as the trough
slides overhead and lapse rates steepen. The trough moves east
Monday night through Tuesday morning with system on tap for
Tuesday afternoon and night. Plunkett/86
.LONG TERM...Wednesday through Sunday...Much like yesterday the
deterministic models and ensembles are in good to excellent
agreement on the evolution of the 500 mb pattern for the coming
week into next weekend. This provides above normal confidence in
the forecast for the next several days. On Wednesday and
Wednesday night a developing trough off the British Columbia Coast
will approach the region. This will result in tightening surface
pressure gradients and increasing S-SW winds ahead of a cold front
that will cross the region on Thursday. Latest GFS shows a strong
SWLY 850 mb jet of 50 kt ahead of the front Wednesday night.
These winds will have the potential to mix down to the surface as
the front moves through. Latest probabilistic NBM shows 60% to
near 100% probabilities of wind gusts exceeding 39 mph areawide,
and a 30-70% chance of winds exceeding 55 mph in gusts mainly
along ridgetops.
Temperatures will warm on Wednesday with the southerly flow and
snow levels will rise above pass level. Thus snow will be
confined to the higher peaks. However as the cold front traverses
the area Thursday, snow levels will drop rapidly to 1000-2000 feet
by Thursday night. At that time any rain will change to snow in
the mountains. Most of the QPF will be confined to the Cascade
East Slopes and Northern Blues on Wednesday but by Thursday, the
lower elevations should see some rain with 60-80% POPS. 50th
percentile QPF from the NBM for the 24 hours ending 12Z Friday is
.10-.25 inches in the lower elevations, .50-.70 inches in the
Northern Blues and Wallowas, and .50-1.25 inches along the Cascade
Crest. Since this precipitation will all be snow in the mountains
there is a good chance (50-60%) that winter highlights will be
needed during this time period.
Friday through Sunday a large upper low will develop and move SEWD
along the coast initially, then inland over the weekend. This will
result in cooler weather and showery conditions especially over
the mountains. Overall, POPS will be on the decrease with time
especially by Sunday when POPS values drop to 10-40%. 78
&&
.AVIATION...00Z TAFs...VFR conditions will prevail through the
forecast period. Winds will be the primary concern with SW-W winds
sustained at 15-25 kt and gusts 30-40 kt ahead of a cold front
that will move from NW to SE across the region this afternoon and
tonight. A band of light rain will accompany the front with a
transition to light snow at KRDM, KBDN and KALW. There is about a
40 percent chance of a brief transition to snow at KPDT early
Monday morning before ending. MVFR visibilities are likely
(60-70%) in the areas where snow is expected. High and mid clouds
will transition to CIGS 035-050 AGL tonight. SCT-BKN stratocumulus
and some mid clouds are expected behind the cold front Monday
with west winds 15-25kt and gusts to 30 kt. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 34 42 27 42 / 90 60 40 20
ALW 35 43 28 42 / 90 80 60 20
PSC 38 49 31 47 / 30 30 10 0
YKM 30 47 24 45 / 40 10 0 0
HRI 37 48 30 47 / 60 30 20 10
ELN 30 42 24 40 / 70 20 10 0
RDM 30 38 24 40 / 70 60 30 0
LGD 31 39 24 36 / 100 90 60 30
GCD 31 41 21 36 / 70 90 40 30
DLS 35 45 32 46 / 80 40 20 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 3 PM PST Monday for ORZ044-507-508-510.
Winter Weather Advisory from 10 PM this evening to 4 AM PST
Tuesday for ORZ050-503-506.
Winter Storm Warning from 7 PM this evening to 4 AM PST Tuesday
for ORZ502.
Winter Storm Warning until 4 PM PST Monday for ORZ509.
WA...Wind Advisory until 3 PM PST Monday for WAZ028-029-521.
Winter Storm Warning from 7 PM this evening to 4 AM PST Tuesday
for WAZ030.
Winter Storm Warning until 4 PM PST Monday for WAZ522.
&&
SHORT TERM...86
LONG TERM....78
AVIATION...78The national radar mosaic for the moment the first event began.
1 heavy snow. Local standard time, as filed.
Touchet SNOTEL reported 17 inches of new snow between 7PM February 25th and 4AM February 27th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2024Every state in 2024This day in weather historyWarnings in Washington, February 2024
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: 1165474.