A fairly strong frontal system moved through western Washington bringing heavy snow to Mount Baker, and to Stevens Pass in the Puget Sound Convergence Zone just behind the front.
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 fairly strong frontal system moved through western Washington bringing heavy snow to Mount Baker, and to Stevens Pass in the Puget Sound Convergence Zone just behind the front.
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 10, 2:00 PM PST, 2 hours earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT FRI APR 10 2015
.SYNOPSIS...A STRONG COLD FRONT WILL MOVE THROUGH WESTERN WASHINGTON
THIS EVENING AND ACROSS THE CASCADES TONIGHT...BRINGING WIDESPREAD
PRECIPITATION AND GUSTY WINDS. COOL MOIST WESTERLY FLOW WILL PREVAIL
SATURDAY INTO SUNDAY WITH SHOWERS IN THE LOWLANDS AND SNOW IN THE
MOUNTAINS. ANOTHER FRONT WILL MOVE THROUGH THE AREA MONDAY...WITH
SHOWERS TUESDAY. HIGH PRESSURE SHOULD BRING DRY WEATHER ON WEDNESDAY.
&&
.SHORT TERM...A STRONG PACIFIC FRONTAL SYSTEM IS BEGINNING TO MOVE
INTO WESTERN WASHINGTON THIS AFTERNOON. THE RADAR SHOWED THE COLD
FRONT NICELY AS IT WAS MAKING LANDFALL THIS AFTERNOON...BRINGING
RAIN TO THE COAST. RAIN HAD STILL NOT SPREAD INLAND VERY FAR...SO
THE WESTERN WASHINGTON INTERIOR HAD CLOUDY SKIES WITH TEMPERATURES
IN THE 50S TO LOWER 60S.
THE COLD FRONT WILL MOVE THROUGH THE INTERIOR OF WESTERN WASHINGTON
THIS EVENING AND ACROSS THE CASCADES OVERNIGHT...BRING PRECIPITATION
TO THE ENTIRE FORECAST AREA. THE FRONT WILL PRODUCE A FAIRLY STRONG
SOUTHWEST PRESSURE GRADIENT AS WELL...WITH BREEZY TO LOCALLY WINDY
CONDITIONS ALONG THE FRONT AND IN THE STRONG SURGE OF ONSHORE FLOW
BEHIND IT.
COOL MOIST WESTERLY FLOW WILL FOLLOW THE FRONT SATURDAY AND SATURDAY
NIGHT AS A BROAD UPPER TROUGH MOVES OVER THE REGION. FOR THE WESTERN
WASHINGTON LOWLANDS THAT WILL MEAN SHOWERY PRECIPITATION...AND A
PUGET SOUND CONVERGENCE ZONE. THE AIR MASS WILL BE SOMEWHAT
UNSTABLE...SO THUNDERSTORMS AND SMALL HAIL ARE POSSIBLE MAINLY AT
THE COAST AND IN THE CONVERGENCE ZONE. SHOWERS SHOULD DECREASE
SUNDAY AS A WEAK UPPER RIDGE BUILDS OVER THE AREA.
FOR THE MOUNTAINS THERE WILL BE LOTS OF SNOW...ESPECIALLY ALONG THE
WEST FACING SLOPES AND ESPECIALLY WHERE THE CONVERGENCE ZONE EXTENDS
INTO THE CASCADES NEAR STEVENS PASS. THE SNOW LEVEL WILL BETWEEN
2000 AND 3000 FT BEHIND THE COLD FRONT AND REMAIN THAT LOW THROUGH
SUNDAY...SO ALL THE HIGHWAY PASSES INCLUDING SNOQUALMIE PASS
WILL HAVE ACCUMULATING SNOWFALL. PRECIPITATION SHOULD GRADUALLY
DECREASE ON SUNDAY...AND BY SUNDAY AFTERNOON THE SNOWFALL TOTALS IN
THE MOUNTAINS COULD BE ONE TO TWO AND A HALF FEET. THE WINTER STORM
WATCH WILL BE UPGRADED TO A WARNING WITH THE AFTERNOON FORECAST
PACKAGE.
THE UPPER RIDGE WILL MOVE EAST OF THE CASCADES SUNDAY NIGHT...AND
ANOTHER FRONTAL SYSTEM WILL MOVE THROUGH THE AREA MONDAY AND MONDAY
NIGHT. THIS FEATURE WILL BRING ANOTHER ROUND OF RAIN TO THE LOWLANDS
AND SNOW TO THE MOUNTAINS. IT COULD ALSO BRING BREEZY TO WINDY
CONDITIONS...BUT THE MODELS HAVE NOT SHOWN MUCH CONSISTENCY IN SUCH
DETAILS FROM RUN TO RUN. MCDONNAL
.LONG TERM...TUESDAY SHOULD BE A DAY OF POST FRONTAL SHOWERS
FOLLOWING THE SYSTEM THAT MOVES THROUGH MONDAY AND MONDAY NIGHT. A
PROGRESSIVE UPPER RIDGE SHOULD BRING DRY WEATHER ON WEDNESDAY. IT
LOOKS LIKE A RATHER WEAK FRONT WILL MOVE THROUGH WESTERN WASHINGTON
THURSDAY...BUT MODELS DIFFER QUITE A BIT ON JUST HOW WEAK IT WILL
BE. FOR NOW THE FORECAST WILL BE A CHANCE OF PRECIPITATION. THERE
COULD BE A FEW SHOWERS BEHIND THAT SYSTEM ON FRIDAY...BUT ANOTHER
PROGRESSIVE UPPER RIDGE WILL MOVE INTO THE OFFSHORE WATERS.
MCDONNAL
&&
.AVIATION...A STRONG COLD FRONT ALONG THE COAST AT 23Z WILL MOVE
INLAND REACHING THE CASCADES BEFORE MIDNIGHT. RAIN HAS SPREAD AS FAR
EAST AS KOLM AT 23Z. VFR CEILINGS ACROSS THE INTERIOR WITH MVFR
CEILINGS ALONG THE COAST. CEILINGS LOWERING OVER THE INTERIOR JUST
AHEAD OF THE FRONT TO 2000-3000 FEET. RAIN WILL CHANGE TO SHOWERS
BEHIND THE FRONT WITH SHOWER ACTIVITY GRADUALLY BECOMING CONFINED TO
THE WEST SLOPES OF THE CASCADES AND OLYMPICS AND TO A CENTRAL PUGET
SOUND CONVERGENCE ZONE. CONDITIONS WILL IMPROVE TO VFR OUTSIDE OF
THE SHOWER ACTIVITY BUT WILL REMAIN MVFR IN THE SHOWERS. FELTON
KSEA...CEILINGS LOWERING DOWN TO NEAR 3000 FEET WITH THE FRONT
AROUND 03Z. CEILINGS IMPROVING BACK UP INTO THE 4000-5000 FOOT RANGE
BY 09Z. SOUTH TO SOUTHWEST WIND 10-15 KNOTS WITH GUSTS TO 20-25 INTO
THE EARLY MORNING HOURS. FELTON
&&
.MARINE...A STRONG COLD FRONT ALONG THE COAST WILL MOVE THROUGH THE
THROUGH THE INLAND WATERS THIS EVENING. SOUTHERLY FLOW AHEAD OF THE
FRONT WILL SHIFT TO MODERATE TO STRONG SOUTHWEST TO WESTERLY BEHIND
THE FRONT THIS EVENING.
GALE WARNINGS CONTINUE FOR THE COASTAL WATERS JUST UNTIL 4 PM WITH
GALE FORCE WINDS ONLY RIGHT WITH THE FRONT. INCREASING POST FRONTAL
WESTERLY GRADIENT THROUGH THE STRAIT WITH GALE WARNING IN EFFECT
THROUGH LATE TONIGHT FOR THE CENTRAL AND EASTERN STRAIT. SMALL CRAFT
ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.
THE ONSHORE FLOW WILL SLOWLY WEAKEN SATURDAY AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD OVER WESTERN WASHINGTON ON SUNDAY.
ANOTHER FRONTAL SYSTEM WILL MOVE THROUGH THE WATERS MONDAY. THIS
FRONT APPEARS THAT IT WILL BE WEAKER THAN THE FRONT THAT MOVES
THROUGH THE WATERS TODAY. FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING COAST AND STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY PUGET SOUND/HOOD CANAL...ADMIRALTY
INLET...AND NORTHERN INLAND WATERS.
&&
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML1 heavy snow, 1 winter storm. Local standard time, as filed.
USFS NWAC station at Mount Baker measured 12 inches snow in 12 hours ending 1 am Apr 11, with a total of 17 inches during warning period.
USFS NWAC station at Stevens Pass measured 12 inches snow in 12 hours ending 9 pm Apr 11, with a total of 18 inches during warning period.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2015Every state in 2015This day in weather historyWarnings in Washington, April 2015
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: 565338, 565339.