A quick-hitting spring storm system brought heavy snow to the Cascades at the end of March.
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.
A quick-hitting spring storm system brought heavy snow to the Cascades at the end of March.
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 Mar 28, 7:43 AM PST, 4 hours 17 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
843 AM PDT Sun Mar 28 2021
.UPDATE /THIS MORNING/...Forecast largely on track this morning so
far so only minor changes made. Rain shield is starting to spread
inland and currently reaches from Whatcom County southeastward to
NW Grays Harbor County. Southerly winds have picked up with gusts
of 20-35 mph along the coast and inland waters. Front is expected
to move through the coast around 18-20z and into the Puget Sound
area around 20-22z. Latest hi-res guidance continues to indicate
the likelihood of convective showers popping up behind the front
with a slightly unstable post-frontal environment. Isolated
thunderstorms will be possible during the afternoon and evening
hours with small hail and heavy downpours. In addition, as
westerly push develops down the Strait of Juan de Fuca, a
convergence zone should form somewhere in the usual area in
western Skagit and Snohomish counties and drop south into King
County. This may spark additional thunderstorms. Snow levels will
fall rapidly behind the front and the convergence zone may be
robust enough for some heavy, wet snow flakes to mix in with the
rain. No accumulation on roads expected given warm-ish ground
temperatures but will continue to monitor trends. Heavy snow
expected in the mountain and this along with gusty winds may lead
to some travel difficulties and possible delays. Those with travel
plans should check WSDOT road conditions before departing. Wind
forecast still on track with winds peaking later this afternoon
and evening. See NPWSEW for latest wind advisory. Previous
discussion follows with updates to aviation and marine.
Carpenter
&&
.SYNOPSIS...A strong spring system will move across the area today
with gusty winds, lowland rain, mountain snow, and isolated
thunderstorms possible. Dry weather returns later on Monday
through much of the week with the possibility of additional
systems arriving by the end of the week.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/...Keeping with the latest
discussion trends, the main hazards of wind speeds, isolated
thunderstorms, and mountain snow will be discussed in detail
below.
Winds: Southerly winds will begin to pick up across the region
this morning ahead of the cold front, increasing as the front
moves through during the day time today. In the wake of the front,
winds will remain elevated, but will have switched to become
westerly. A westerly surge down the Strait of Juan de Fuca will
follow, and will contribute to the strength of a convergence zone
that will be discussed subsequently. Although it will be gusty
area-wide, the strongest winds will materialize along the coast,
in the northern inland waters, and in western Whatcom and Skagit
counties. These locations have Wind Advisories going into effect
beginning later this morning. The waters of Puget Sound and the
immediate vicinity will also experience elevated wind speeds and
have Wind Advisories that will go into effect at noon. Gusts of 30
to 45 mph will be common with a few spots reaching 50 mph.
Elsewhere, expect gusts to be between 20 to 40 mph. Winds will
begin to ease tonight into Monday morning.
Mountain Snow: Hi-res guidance has come into more focus to depict
the development of a convergence zone setting up likely over
Stevens Pass first, then drifting south over Snoqualmie Pass this
evening. Heavy snow on the order of 8-12 inches is expected,
although more could fall as a result of a robust convergence zone
set up. The North Cascades maintain a winter storm warning and are
on track to receive 12 to 24 inches of snow. Additionally, the
gusty winds are forecast to impact the mountains as well. Heavy
snow and gusty conditions could make for difficult travel through
the passes. Check with WSDOT road conditions before travel. Snow
activity will decrease tonight, with snow levels coming down to
around 500 feet by Monday morning. With most of the moisture out
of the area, only isolated showers may remain and additional
accumulation is unlikely. A rain/snow mix for the foothills
remains in the forecast.
Thunderstorms: The post-frontal environment remains somewhat
favorable for the development of isolated thunderstorms. The areas
with the most potential will start off along the coast and through
the Strait of Juan de Fuca, and will expand to include more inland
locations across portions of Puget Sound in the afternoon.
Thunderstorms embedded in the potentially vigorous convergence
zone are possible and may impact portions of Snohomish and King
Counties through the early evening hours. Small hail, lightning
strikes, and locally heavy downpours are possible with any storms
that develop.
Tuesday looks to be much quieter as high pressure is forecast to
make a return to the area. Warming temperatures are expected, with
afternoon highs in the upper 50s.
Kristell
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...High pressure looks to
remain in place through much of the mid week period. High
temperatures on Wednesday could quite possibly crack the 60 degree
mark across portions of Puget Sound with plenty of sunshine. At
this time, the ridge looks to break down on Thursday and allow
another system into the area from the northwest. At this time, the
late week systems do not seem particularly strong, but will likely
trend the temperatures down slightly. Additional details will be
available in the coming days.
Kristell
&&
.AVIATION...Southwest flow aloft becoming northwest behind a
strong cold front later this afternoon. Cigs and vsby will drop with
the rain in the front as it moves through Western Washington today
with areas of MVFR and some local IFR conditions. At 8am the front
is moving through the north coast and it will move through the I-5
corridor midday or early afternoon and through the Cascades this
afternoon and evening. The mountains will be obscured. Blustery
southerly winds will turn to westerly behind the front. A Puget
Sound Convergence Zone will develop at times tonight. 19
KSEA...The 15z TAF is in the ballpark. There is a chance that the
PSCZ drops down over Seattle at times tonight so that will be
something to watch for later today.
&&
.MARINE...Strong cold front with gale warnings up for the marine
areas as blustery southerly winds shift to westerly gales for
most areas this afternoon. Puget Sound will have southerlies
turning southwest and then a PSCZ tonight which will help decrease
the winds while northwesterly gales persist elsewhere. Surface
high pressure will be building over the area through Monday night
with winds easing. High pressure remains over the waters Tuesday
and Wednesday with light winds over the inland waters and
northwesterly winds easing over the coastal waters. A weaker
system reaches the area Thursday. For the coastal waters, seas
will be 13 to 16 ft tonight and Monday so conditions will become
rough on the Grays Harbor Bar. 19
&&
.HYDROLOGY...No river flooding is expected over the next seven
days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from noon today to 6 PM PDT this evening for
Bremerton and Vicinity-Everett and Vicinity-Hood Canal Area-
Seattle and Vicinity-Tacoma Area.
Winter Weather Advisory until 5 AM PDT Monday for Cascades of
Pierce and Lewis Counties.
Winter Storm Warning until 5 AM PDT Monday for Cascades of
Snohomish and King Counties-Cascades of Whatcom and Skagit
Counties.
Wind Advisory until midnight PDT tonight for Admiralty Inlet
Area-Central Coast-North Coast-San Juan County-Western
Skagit County-Western Whatcom County.
Wind Advisory from 1 PM this afternoon to 3 AM PDT Monday for
Eastern Strait of Juan de Fuca-Western Strait of Juan De
Fuca.
PZ...Small Craft Advisory until 2 AM PDT Tuesday for Grays Harbor Bar.
Small Craft Advisory from 6 AM to 6 PM PDT Monday 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.
Gale Warning until 6 AM PDT Monday for Admiralty Inlet-Central
U.S. Waters Strait Of Juan De Fuca-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-East Entrance U.S. Waters Strait Of Juan De Fuca-
Northern Inland Waters Including The San Juan Islands-West
Entrance U.S. Waters Strait Of Juan De Fuca.
Gale Warning until 6 PM PDT this evening for Puget Sound and
Hood Canal.
&&
www.weather.gov/seattlePRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1148 AM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1100 AM NON-TSTM WND GST 11 NW CLEARWATER 47.67N 124.48W
03/28/2021 M48 MPH JEFFERSON WA MESONET
MESONET STATION DESW1 DESTRUCTION ISLAND.
&&
GRUBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1212 PM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1150 AM NON-TSTM WND GST 9 NW LANGLEY 48.14N 122.52W
03/28/2021 M58 MPH ISLAND WA MESONET
MESONET STATION EW2796 CAMANO ISLAND.
&&
GRUBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1214 PM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1209 PM NON-TSTM WND GST PORT TOWNSEND 48.12N 122.75W
03/28/2021 M49 MPH JEFFERSON WA MESONET
MESONET STATION FW4667 PORT TOWNSEND.
&&
GRUBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1215 PM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1151 AM NON-TSTM WND GST 4 ESE PORT TOWNSEND 48.10N 122.69W
03/28/2021 M46 MPH JEFFERSON WA MESONET
MESONET STATION XMPL MARROWSTONE POINT
LIGHT.
&&
GRUBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1224 PM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1204 PM NON-TSTM WND GST 4 SSW LYNDEN 48.89N 122.49W
03/28/2021 M45 MPH WHATCOM WA MESONET
MESONET STATION TPOLE SR 539/544 LYNDEN.
&&
GRUBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1236 PM PDT SUN MAR 28 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1229 PM NON-TSTM WND GST 6 W MARIETTA 48.80N 122.71W
03/28/2021 M45 MPH WHATCOM WA MESONET
MESONET STATION CW1394 SANDY PT. SHORES.
&&
GRUB2 heavy snow. Local standard time, as filed.
Snow began to fall in the North Cascades around noon on March 28. Within a 12 hour period, 24 inches of new snow was recorded at the Mount Baker Ski Area. Snow then continued through the early morning hours on the 29th before ending.
Snow began around midday on the 28th across the Central Cascades and within 12 hours, 13 inches of new snow was recorded at Stevens Pass. Snow then continued through the morning hours of the 29th before coming to an end.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2021Every state in 2021This day in weather historyWarnings in Washington, March 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: 951651, 951652.