An approaching cold front lead to the tightening of the pressure gradient across the Washington Cascades, which resulted in strong northwest winds developing through the Kittitas valley the afternoon of May 31st.
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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 approaching cold front lead to the tightening of the pressure gradient across the Washington Cascades, which resulted in strong northwest winds developing through the Kittitas valley the afternoon of May 31st.
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 May 31, 9:15 AM PST, 3 hours 45 minutes earlier.
Area Forecast Discussion
National Weather Service Pendleton OR
1015 AM PDT Sat May 31 2025
.Updated for Aviation...
.AVIATION...
18Z TAFS...VFR conditions are expected through the TAF period.
Winds are expected to become gusty through the late morning and
into the afternoon hours and will remain gusty into the evening
hours. Wind gusts in the 25 to 30 kt range are expected at all
sites except ALW and PSC where gusts should be in the 20 to 25 kt
range.
&&
.PREV DISCUSSION... /issued 458 AM PDT Sat May 31 2025/
UPDATED AVIATION DISCUSSION...
SHORT TERM...Today through Monday...Overnight satellite imagery
shows clouds streaming into the forecast area ahead of an upper-
level trough moving into the PacNW this weekend. While most of the
moisture associated with this system will fall to our north, the
cold front moving through the forecast area will bring gusty and
even strong winds through the Cascade Gaps and into the Columbia
Basin. A High Wind Warning remains in effect for the Kittitas Valley
as a result, with Wind Advisories in effect for the Basin, North
Central Oregon, and the Simcoe Highlands.
NAM pressure gradient guidance shows a 10-11 mb cross-Cascade
gradient through the Kittitas Valley, which is nearing what we'd
expect for wind gusts up to 60 mph for the Valley. The gradient
through the Basin also wavers around the 10-12 mb range, which is
generally sufficient for an advisory (gusts over 45 mph), even if
models themselves are a bit gun shy on wind gusts themselves through
the area. Expect winds to start ramping up by the early afternoon
hours, and maxing out between 4 and 8 PM. While fuels are dry in
areas such as the Kittitas and Yakima Valleys, the northwesterly
origin of this front will bring in cooler temps and thus higher RHs,
thus critical fire weather conditions are not anticipated. Still,
wind events of this magnitude are unusual for this time of year, so
the public should still be wary of the fire spread potential under
these gusty winds.
Quieter conditions will then prevail on Sunday as the trough axis
sweeps through and dry northwesterly flow prevails overhead. Will
still see some breezy conditions through the Cascade Gaps (gusts up
to and over 30 mph) so long as NW flow prevails, but temps will
generally be seasonable after peaking on Saturday, with highs in the
low 80s in the lower Basin and 70s elsewhere across the lowlands.
Evans/74
LONG TERM...Tuesday through Saturday...Overall, the ensemble NWP
guidance is in good agreement with the PacNW remaining between an
upper level ridge and longwave trough through the extended period.
However, the models seem to have a shortwave trough Wednesday night
into Thursday evening along with light rain for Thursday as well,
but confidence is low (<20%) due to the differences in its
amplitude. Regardless, a mostly dry period will remain across the
forecast area.
Moreover, the Blues, central OR, and Lower Columbia Basin will
remain lightly breezy up to 20 mph or less through this long term.
Due to the cross-cascade pressure difference, Thursday and Friday
will be our most windy days for the Cascades gaps with gusts at 30-
35 mph. NBM CONUS suggests a 20-40% probability of sustained winds
up to 25 mph with gusts of 35 mph for Thursday and Friday during
evening hours mainly at the Kittitas Valley and the Gorge, though
with a >40% prob for gusts at 30 mph including portions of Yakima
Valley. These locations are where the cross-cascade pressure
difference will be the greatest. Nonetheless, it is doubtful that
these winds will reach to advisory level at this time.
High temperatures will increase by a few degrees to the 80s or above
at the Columbia Basin with everywhere else mainly in the 70s (70-90%
confidence). As this dry period prevails, this could drop RHs and
further increase temps through the week, making Saturday the warmest
and driest day with temps in the high 80s to low 90s and RHs below
20% across the Columbia Basin, central OR and portions of John Day
Highlands. Given the low RHs and warmer temps, pockets of Moderate
Heat Risk is forecasted over mainly the Lower Columbia Basin. The
probability of maximum temps >85 degrees is 50-70%, based from the
NBM CONUS. Feaster/97
AVIATION...12Z TAFs...VFR conditions will prevail with mid to high
clouds. Throughout today, the surface pressure differences will
remain strengthening thus inducing sustained winds of 15-25 kts with
gusts of 20-30 kts for all sites. However, sustained winds could
exceed 25 kts with gusts of 35-45 kts during the afternoon and
evening hours at KDLS (>60% probability) and KPDT/KYKM/KPSC (30-40%
prob). Feaster/97
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 87 48 75 46 / 0 0 0 0
ALW 88 50 75 49 / 0 0 0 0
PSC 92 51 80 47 / 0 0 0 0
YKM 89 49 79 48 / 0 0 0 0
HRI 89 49 79 47 / 0 0 0 0
ELN 81 45 74 47 / 0 0 0 0
RDM 82 40 72 38 / 0 0 0 0
LGD 89 48 69 43 / 0 10 0 0
GCD 91 46 71 41 / 0 10 0 0
DLS 80 51 80 50 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 11 PM PDT this evening for ORZ041-510.
Wind Advisory from 2 PM this afternoon to 11 PM PDT this evening
for ORZ044-508.
Wind Advisory from 5 PM this afternoon to 11 PM PDT this evening
for ORZ507.
WA...Wind Advisory until 11 PM PDT this evening for WAZ024-521.
Wind Advisory from 5 PM this afternoon to 11 PM PDT this evening
for WAZ028.
High Wind Warning from 2 PM this afternoon to 2 AM PDT Sunday
for WAZ026.
&&
SHORT TERM...74
LONG TERM....97
AVIATION...77The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The mesonet station PS017 measured a 66 mph gust at 1630 PDT on May 31st. The ASOS KELN measured a 58 mph gust at 1445 PDT on May 31st.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2025Every state in 2025This day in weather historyWarnings in Washington, May 2025
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: 1268423.