Cooler and wetter than normal conditions continued towards mid April as weather systems continued to move into Western Washington from off the Pacific. On April 9th, heavy snow was reported at Snoqualmie Pass, with then an additional system moving into Oregon bringing lowland snow to areas south of Olympia.
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 SEW wrote it up.
Cooler and wetter than normal conditions continued towards mid April as weather systems continued to move into Western Washington from off the Pacific. On April 9th, heavy snow was reported at Snoqualmie Pass, with then an additional system moving into Oregon bringing lowland snow to areas south of Olympia.
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 Seattle, WA wrote its last area forecast discussion before the first event at Apr 9, 8:04 AM PST, 2 hours 56 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
904 AM PDT Sat Apr 9 2022
.UPDATE...The forecast is in good shape this morning with no
changes needed. Troughing will continue to deepen over the region
through the day today. This will help maintain a generally
unsettled/marginally unstable environment that will foster an
increase in shower coverage and may also result in the development
of a few thunderstorms, especially this afternoon and evening. In
addition, with snow levels between 1000-2000 feet, mountain snow
can be expected, including the Passes. Travelers should plan for
wintry driving conditions. Temperatures will also be quite cool in
the lowlands, as compared to recent days, with highs struggling
to reach 50.
The threat of convection will slowly decrease after sunset this
evening, with a robust shortwave trough/vort lobe diving towards
the area from the NW. This will reinforce shower coverage and
light rain across the area this evening and overnight.
Previous discussion provided below with an updated marine and
aviation section.
Kovacik
&&
.PREV DISCUSSION... /issued 349 AM PDT Sat Apr 9 2022/
.SYNOPSIS...A weather pattern shift will bring cooler and more
unsettled conditions through the weekend. This pattern is expected
to linger through much of next week.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...Western WA remains under
moist W/NW flow today with a cool and unstable air mass in place.
Expect additional showers across the region with possible
thunderstorms and small hail (as seen yesterday). Up in the
mountains, snow levels remain low (around 1500 feet) and showers
will continue to impact the Olympics and Cascades as well.
Convergence zone showers will be aimed at Stevens and Snoqualmie
passes through much of the day (and evening) with periods of heavy
snow possible. Higher snow accumulations are possible at Paradise
on Mount Rainer too and the Winter Weather Advisory has been
extended through this evening. With the cooler air mass in place
temperatures will dip below normal with highs only in the upper
40s.
The next disturbance will roll through western WA tonight into
Sunday for another period of wet weather. Sunday morning's lows
will be chilly and in the lower to mid 30s. There's a threat of
lowland rain/snow mix due to low snow levels (around 1000 ft) but
widespread/significant snowfall accumulations are not expected.
Afternoon temps will in the mid to upper 40s.
Another cool/wet system arrives Sunday night into Monday as an
upper level low cuts through the PacNW. Once again there's another
threat of lowland rain/snow mix but were not expecting
accumulations. Snow levels will be rising through the day with
highs near 50. The mountains will see a few more inches of snow
but heavy accumulations look unlikely at this time. 33
.LONG TERM /TUESDAY THROUGH FRIDAY/...Broad longwave troughing
over the Northwest will keep the air mass cool and unstable for
additional showers as we move through Thursday. Lows will be in
the mid to upper 30s with highs near 50. Drier and more stable
weather is possible toward the end of the week with temperatures
warming a few degrees. 33
&&
.AVIATION...Board upper troughing will continue across the
Pacific Northwest today, for west-northwesterly flow aloft. An
upper level shortwave will move across the region, helping to re-
invigorate showers across the area. The airmass will be moist and
unstable- with a slight chance of thunderstorms possible this
afternoon and evening. With persistent onshore flow in the low
levels, guidance still hints at a PSCZ re-developing across the
Central Sound this afternoon. Overall, conditions will likely
remain a mix of VFR to MVFR through the day with areas of low to
mid clouds present. Expect more widespread MVFR conditions to
develop tonight. Surface winds will be breezy- generally at 10-15
kts, with gusts to 25 kts possible at times.
KSEA...Expect a mix of low and mid clouds today for a mix of VFR
to MVFR conditions. Showers to continue through the day. A
convergence zone will likely develop to the north of the terminal
this afternoon, though confidence remains low as to whether it
sink south into the terminal at this time. Winds will generally be
out of the southwest at 10-15 knots with higher gusts to 25 kts
possible at times.
14/Butwin
&&
.MARINE...A low pressure system will drop down along Vancouver
Island today and make its way inland along the northern tier of
the Olympic Peninsula tonight. Overall, expect onshore flow to
continue today with small craft advisories for most of the area
waters. The exception are the waters of the Central and Eastern
Strait of Juan de Fuca- where a gale warning remains in effect
through tonight. The next system will then move into the region
Sunday into Monday. While there has been a bit more consensus
among latest EPS and GEFS ensemble guidance, uncertainty still
remains regarding the track and strength of the low pressure
system. The strength of the winds, particularly across the
offshore waters, will be dependent on this- so will need to see
how guidance trends over the next day. However, it is likely that
there will be another round of headlines for the area waters.
Seas across the coastal waters will hover at 9-11 feet into
Sunday, before briefly subsiding to 6-8 feet Sunday night. Seas
will then build to above 10 feet again Monday into Tuesday,
before steadily decreasing midweek.
14/Butwin
&&
.HYDROLOGY...No river flooding expected in the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 11 PM PDT this evening for
Cascades of Pierce and Lewis Counties-Cascades of Snohomish
and King Counties.
PZ...Small Craft Advisory until 8 AM PDT Sunday for Coastal Waters
From Cape Flattery To James Island 10 To 60 Nm-Coastal
Waters From Cape Flattery To James Island Out 10 Nm-Coastal
Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From James Island To Point Grenville Out 10
Nm-Coastal Waters From Point Grenville To Cape Shoalwater
10 To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater Out 10 Nm.
Small Craft Advisory until 9 PM PDT this evening for Grays
Harbor Bar.
Gale Warning until 8 PM PDT this evening for Central U.S. Waters
Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
Juan De Fuca.
Small Craft Advisory until 11 PM PDT this evening for Admiralty
Inlet-Northern Inland Waters Including The San Juan Islands-
Puget Sound and Hood Canal.
Small Craft Advisory until 5 AM PDT Sunday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
&&
www.weather.gov/seattle1 heavy snow, 1 winter weather. Local standard time, as filed.
Heavy snow affected Snoqualmie Pass April 9th through the 10th. Heavy snow began during the late morning hours on the 9th and continued through the afternoon on the 10th. Around 18 inches of new snow was reported at the Pass within a 24 hour period. Snow then tapered by the evening of the 10th.
Late season snow event across portions of the lowlands of Western Washington near mid April. A strong storm system moving into Oregon carried enough moisture north of it to bring accumulating snow to portions of the Lower Chehalis Valley. Areas of the city of Chehalis reported around 2 to 3 inches of new snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2022Every state in 2022This day in weather historyWarnings in Washington, April 2022
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: 1021876, 1021877.