The Stillaguamish River reached record level. There were several roads washed out in Kitsap county.
Every event with a place to put it. 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 SEW wrote it up.
The Stillaguamish River reached record level. There were several roads washed out in Kitsap county. 2 homes were damaged from mudslides.
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 Dec 11, 9:15 PM PST, 3 hours 45 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 PM PST SAT DEC 11 2010
.SYNOPSIS...A STRONG WARM FRONT WILL MOVE NORTH ACROSS THE AREA
TONIGHT. THIS WILL BRING AN EPISODE OF VERY WET AND UNSEASONABLY
WARM WEATHER TONIGHT THROUGH SUNDAY NIGHT...WITH SOME FLOODING
LIKELY. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT. A COLDER BUT
VIGOROUS FRONTAL SYSTEM WILL MOVE THROUGH MONDAY NIGHT BRINGING MORE
RAIN WIND AND MOUNTAIN SNOW.
&&
.SHORT TERM...THE UPPER LEVEL WARM FRONT LIFTED THROUGH THE AREA
EARLIER THIS AFTERNOON. THE 00Z FREEZING LEVEL AT KUIL WAS NEAR 10K
FT AND THE PROFILIERS ALL SHOW A SHARP JUMP IN THE MAIN FREEZING
LEVEL. HOWEVER...THE SURFACE WARM FRONT HAS LAGGED BUT APPEARS TO BE
FINALLY LIFTING FROM SRN WA INTO CENTRAL WA...SHIFTING THE HEAVIEST
PRECIP A BIT FURTHER N. SLY WINDS S OF THE SURFACE WARM FRONT ARE
BRINGING WARMING TEMPS WITH A NOTICEABLE JUMP FROM THE 40S INTO THE
50S FROM THE S SOUND SWD. KOLM IS UP ALMOST TEN DEGREES OVER THE
PAST COUPLE HOURS. THE MOVEMENT OF THE WARM FRONT TONIGHT WILL BE
KEY ON WHERE THE HEAVIEST RAIN FALLS. THE ENTIRE AREA WILL SEE RAIN
THROUGH SUNDAY WITH MANY RIVERS LIKELY TO FLOOD. IF THE FRONTAL BAND
STALLS WITH LITTLE MOVEMENT...THEN SOME RIVER BASINS WILL SEE THE
HIGHER RAINFALL AMOUNTS. IF THE FRONT OSCILLATES...PRECIP WILL BE
MORE WIDESPREAD BUT POSSIBLY ON THE LOWER END OF ESTIMATES. SEE THE
LATEST HYDRO SECTION FOR FURTHER DETAILS.
WARMER AIR IS LIFTING NWD OVER WA BUT THE ELY CROSS CASCADE GRADIENT
IS MAINTAINING SUB ZERO TEMPERATURES IN THE PASSES. ROUGHLY 6 TO 10
INCHES HAVE OF SNOW HAVE FALLEN AT BOTH SNOQUALMIE AND STEVENS PASS
WITH TEMPS AT THE SUMMIT STILL IN THE UPPER 20S. PARADISE HAD
SIMILAR SNOW AMOUNTS BUT IT APPEARS WARMING ALOFT IS BRINGING A
SWITCH TO RAIN. IT SEEMS LIKELY THE COLD LAYER IS BECOMING RATHER
SHALLOW IN THE PASSES BY THIS TIME AND A FEW HOURS OF FREEZING RAIN
IS POSSIBLE. THIS IS ALREADY ADDRESSED IN THE WINTER WEATHER
ADVISORY WHICH WILL REMAIN IN EFFECT UNTIL MIDNIGHT. STRONGER SW
FLOW ALOFT SHOULD MIX OUT THE PASSES AFTER MIDNIGHT WITH ALL PRECIP
GOING OVER TO RAIN.
THE HEAVIEST PRECIP WILL PROBABLY FALL WITH THE COLD FRONT AS IT
SLIDES SE ACROSS WRN WA THROUGH THE DAY SUNDAY. MODELS AGREE THAT
PRECIP WILL EASE AND BECOME SHOWERY BEHIND THE FRONT SUNDAY EVENING.
COOLER AIR WILL FILTER IN BEHIND THE FRONT WITH THE SNOW LEVEL
FALLING BACK DOWN TO 4000 FEET BY MONDAY MORNING. SHOWERS WILL
PERSIST MONDAY UNTIL ANOTHER FRONT ARRIVES.
MODELS BRING ANOTHER VIGOROUS AND COLDER FRONT INTO THE AREA MONDAY
NIGHT AND TUESDAY. SNOW LEVELS WILL BE LOWER WITH THIS SYSTEM
STARTING OFF NEAR 4000 FEET MONDAY NIGHT AND FALLING TO NEAR 2000
FEET BEHIND THE FRONT TUESDAY. THE 00Z NAM QPF AMOUNTS WOULD
INDICATE AT LEAST ADVISORY LEVEL SNOW...AND POSSIBLY WARNING
AMOUNTS. A WATCH MAY NEED TO BE ISSUED BUT WILL WAIT TO SEE
ADDITIONAL MODEL RUNS. THIS WILL CERTAINLY RAISE THE THREAT OF
AVALANCHES...SEE THE AVALANCHE SECTION BELOW. MERCER
.LONG TERM...PREVIOUS DISCUSSION FOLLOWS...THE REMAINDER OF NEXT
WEEK LOOKS COOL AND UNSETTLED WITH A PROGRESSIVE PATTERN SENDING A
SERIES OF IMPULSES THROUGH THE AREA. SNOW LEVELS WILL BE LOWER
ALLOWING FOR SNOW DOWN TO THE PASSES AT TIMES AND CERTAINLY
ACCUMULATING AT THE SKI RESORTS. MERCER/SCHNEIDER
&&
.AVIATION...RAIN...MODERATE TO HEAVY AT TIMES WILL AFFECT WESTERN WA
TONIGHT THROUGH SUNDAY AS A WARM FRONT STALLS OVER THE REGION. THE
COLD FRONT WILL SHIFT SE THROUGH THE AREA LATE SUNDAY AFTERNOON.
ANTICIPATE MVFR TO IFR CONDITIONS...ALONG WITH GUSTY SOUTHERLY
WINDS. HIGHEST WINDS WILL BE FOUND ALONG THE COAST TONIGHT. RAIN AND
WIND WILL DECREASE SUNDAY NIGHT. 33
KSEA...RAIN AT TIMES TONIGHT THROUGH SUNDAY...WITH MVFR TO IFR
CONDITIONS. SOUTH FLOW WILL INCREASE SUN MORNING AS THE COLD FRONT
STARTS TO SHIFT INLAND. PRECIP WILL DECREASE SUN EVENING. 33
&&
.MARINE...STRONG WARM FRONT IS LIFTING NORTH THROUGH WESTERN
WA...WITH STRONG S/SE FLOW ACROSS MOST AREAS. FORECAST IS ON TRACK
WITH NO CHANGES TO THE PREVIOUS PACKAGE...GALE WARNING REMAINS IN
EFFECT FOR THE COASTAL WATERS AND WEST ENTRANCE JUAN DE FUCA WITH
SMALL CRAFT ADVISORIES REMAINING ZONES. WINDS WILL SHIFT TO THE
W/SW ON SUNDAY AS THE COLD FRONT SHIFTS INLAND. STILL LOOKS BLUSTERY
FOR THE REGION BUT LOOKS LIKE SUB-GALE WINDS. WILL LIKELY KEEP SMALL
CRAFT ADVISORIES FOR ALL WATERS THROUGH AT LEAST SUNDAY
AFTERNOON...THIS MATCHES THE CURRENT FORECAST.
IN ADDITION...SEAS WILL BUILD TO 12-14 FT LATE TONIGHT INTO EARLY
SUNDAY AND REMAIN RATHER HIGH INTO MONDAY.
THE WEATHER PATTERN REMAINS ACTIVE THROUGH MID WEEK AS ADDITIONAL
FRONTS SWEEP THROUGH THE REGION. 33
&&
.HYDROLOGY...SURFACE OBSERVATIONS SHOW THE WARM FRONT HAS MOVED
NORTH INTO THE AREA TONIGHT. AT 04Z THE FRONT WAS BETWEEN TACOMA AND
OLYMPIA. HEAVIEST PRECIPITATION WAS OVER THE CENTRAL CASCADES
BETWEEN STEVENS AND SNOQUALMIE PASS WITH AROUND AN INCH OF RAIN IN
THE FOUR HOURS ENDING AT 04Z. 00Z MODEL RUNS CONTINUING WITH THE
IDEA OF THE WARM FRONT STALLING OVER NORTHERN AND CENTRAL WESTERN
WASHINGTON TONIGHT INTO SUNDAY MORNING WITH THE HEAVIEST
PRECIPITATION OVER THE OLYMPICS AND CENTRAL AND NORTHERN CASCADES
FROM ABOUT THE SOUTHERN SKAGIT DRAINAGE TO THE SNOQUALMIE DRAINAGE.
THE FRONT LATER SUNDAY MORNING INTO SUNDAY AFTERNOON AND EARLY
EVENING WILL SAG SOUTHEAST AS A COLD FRONT.
THE QPF FORECAST AND THE RESULTING RIVER FORECASTS ARE ALL BASED ON
THIS IDEA. TOTAL RAINFALL AMOUNTS THROUGH SUNDAY NIGHT WILL BE
MAINLY 1 TO 3 INCHES OVER THE LOWLANDS...WITH 4 TO 9 INCHES OVER THE
MOUNTAINS. THE ATMOSPHERIC RIVER OBSERVATORY AT WESTPORT SHOWED THE
SNOW LEVEL ROSE TO NEARLY 10K FEET THIS AFTERNOON. THE ARO AT
RAVENSDALE ALSO SHOWED AN INCREASE IN THE FREEZING LEVEL LATER THIS
AFTERNOON AND CURRENTLY SHOWS THE FREEZING LEVEL AROUND 8000 FEET.
ACARS SOUNDINGS ALSO SHOW THE FREEZING LEVEL NEAR 8000 FEET OVER
SEATTLE. EASTERLY GRADIENTS ACROSS THE CASCADES HAVE KEPT A SHALLOW
LAYER OF BELOW FREEZING AIR IN SNOQUALMIE AND STEVENS PASSES BUT
WITH THE WINDS ALOFT AT THE PASS LEVELS 30-40 KNOTS OUT OF THE
SOUTHWEST THE SHALLOW LAYER OF COLD AIR SHOULD GET MIXED OUT
OVERNIGHT MAKING ALL OF THE MOUNTAIN PRECIPITATION IN THE FORM OF
RAIN.
RIVER MODELS SHOW FLOODING ON ALL MAIN STEM RIVERS FLOWING OFF THE
NORTH CASCADES...FROM THE NOOKSACK IN WHATCOM COUNTY TO THE
SNOQUALMIE IN KING COUNTY. THE RIVERS THAT FLOW OUT OF THE REGION OF
HEAVIEST RAINFALL ALL GO TO MODERATE OR MAJOR FLOOD STAGE. THIS
INCLUDES THE UPPER SKAGIT...THE STILLAGUAMISH...THE SNOQUALMIE...THE
TOLT...AND THE SNOHOMISH. FLOOD WARNINGS FOR THESE RIVERS WENT OUT
THIS MORNING.
WARNINGS ARE ALSO OUT FOR THE CHEHALIS...NEWAUKUM...AND SKOOKUMCHUCK
RIVERS.
FLOOD WARNINGS WILL ALSO CONTINUE FOR THE RIVERS FLOWING OFF THE
SOUTHERN OLYMPICS...THE SKOKOMISH AND SATSOP. ON THE OTHER HAND
RIVERS ON THE NORTHERN OLYMPIC PENINSULA SEEM TO BE AT SOMEWHAT
LESSER RISK. THE ELWHA IS FORECAST TO CREST WELL BELOW FLOOD STAGE.
THIS COULD TRANSLATE INTO CRESTS BELOW FLOOD STAGE ON OTHER RIVERS
INCLUDING THE DUNGENESS AND BOGACHIEL.
RIVERS FLOWING OUT OF THE CENTRAL CASCADES WILL RISE SHARPLY AS
WELL. SOME OF THEM...OR CERTAIN REACHES OF SOME OF THEM...WILL
PROBABLY EXPERIENCE MINOR FLOODING. WARNINGS ARE CURRENTLY OUT FOR
THE DESCHUTES...NISQUALLY...AND COWLITZ NEAR RANDLE.
IN ADDITION...IT IS NOT JUST THE MAIN STEM RIVERS THAT ARE FLOOD
RISKS. LOCAL FLOODING FROM SMALL STREAMS AND URBAN FLOODING OF LOW
LYING STREETS IS ALSO POSSIBLE ESPECIALLY FROM SEATTLE
NORTHWARD.
THE GREEN RIVER IS ON ONE OF THE LEAST FLOOD-PRONE RIVERS IN WESTERN
WASHINGTON. THE AMOUNT OF RAINFALL IN THE GREEN RIVER BASIN IS NOT
EXPECTED TO BE OF CONCERN FOR HOWARD HANSON DAM OPERATIONS OR FOR
FLOODING ON THE LOWER GREEN RIVER BASIN...THAT IS FROM THE CITY OF
AUBURN DOWNSTREAM THROUGH KENT... RENTON AND TUKWILA.
ON THE RURAL PORTION OF THE RIVER UPSTREAM FROM AUBURN TO HOWARD
HANSON DAM...THERE IS A SLIGHT RISK OF MINOR FLOODING...TYPICAL OF
FLOODING THAT HAS OCCURRED THERE IN RECENT PAST FLOOD EVENTS OF THIS
MAGNITUDE. FLOODING IN THE MIDDLE GREEN RIVER BASIN CAN OCCUR WITH
LESSER AMOUNTS OF RAINFALL THAN WHAT IT WOULD TAKE TO BRING ANY
THREAT TO THE LOWER BASIN. FELTON
&&
.AVALANCHE...HEAVY PRECIPITATION HAS BEGUN OVER THE MT HOOD AREA AND
IS EXPECTED TO LIFT TO THE CASCADES THROUGH THE DAY ALONG WITH
SIGNIFICANT WARMING...ESPECIALLY TONIGHT. SNOW SHOULD CHANGE TO RAIN
BY LATE SATURDAY IN MOST AREAS WITH THE EXCEPTION OF THE CASCADE
PASSES DUE TO COOL EASTERLY SURFACE FLOW. THE CREST LEVEL WINDS
SHOULD BE VERY STRONG BY LATE SATURDAY AS WELL.
THIS WEATHER IS EXPECTED TO PRODUCE A SIGNIFICANT AVALANCHE CYCLE
CAUSING A HIGH DANGER THROUGHOUT THE OLYMPICS AND
CASCADES...ESPECIALLY SATURDAY NIGHT AND INTO SUNDAY. THE HIGH
DANGER IS INITIALLY EXPECTED AT MT HOOD STARTING SATURDAY AFTERNOON
AND IN THE OLYMPICS AND WASHINGTON CASCADES STARTING SATURDAY NIGHT.
AN AVALANCHE WARNING IS BEING ISSUED SATURDAY MORNING TO HIGHLIGHT
THE INCREASING DANGER. PLEASE VISIT WWW.NWAC.US FOR DETAILS. KRAMER
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND/OR WARNINGS FOR PORTIONS OF THE
FORECAST AREA.
.WINTER WEATHER ADVISORY FOR THE NORTH AND CENTRAL CASCADE
PASSES UNTIL MIDNIGHT.
.AVALANCHE WARNING FOR THE WESTERN SLOPES OF THE CASCADES.
PZ...SMALL CRAFT ADVISORY COAST...CENTRAL AND EAST STRAIT OF JUAN DE
FUCA...ADMIRALTY INLET...NORTHERN INLAND WATERS AND PUGET
SOUND AND HOOD CANAL.
.GALE WARNING COASTAL WATERS THROUGH SUNDAY MORNING.
.GALE WARNING WEST ENTRANCE TO THE STRAIT TONIGHT.
.SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR CONDITIONS.
FOR AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION...PLEASE SEE
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.The national radar mosaic for the moment the first event began.
6 flood, 1 debris flow. Local standard time, as filed.
All of highway 106 in Mason county was closed due to flooding and mudslides. A foot bridge in the Tahuya State Forest was closed after floods washed out the concrete entry. Several homes were reported flooded in Mason county.
About 33 homes, and one business, were damaged in Granite Falls, Arlington, and Stanwood when the Stillaguamish River hit record flood stage. Parts of Highway 530 were closed. About 240 homes were issued a voluntary evacuation, while 6 people had to be rescued by hovercraft near Granite Falls.
There was some damage along the Skagit river.
Parts of Highway 20 between Newhalem and Diablo were washed away by heavy rain and flooding.
About 200 people were trapped near Port Orchard when Hunter road was washed out by a raging creek - it is the only road in and out of a neighborhood. Lake Flora Rd was also closed near highway 3 where it was washed out.
A mudslide knocked trees and power pole transformer into a person's garage near the Burke-Gilman trail. A mudslide closed Perrigo Park in Redmond when it knocked debris and a power pole into the park. A home in Burien slid down a hill, damaging it. Three homes on Mercer Island were severely damaged in a landslide. A landslide caused damage to a hillside in Newcastle. Railroad tracks were hit with minor slides in several different areas.
There was major flooding along the Snoqualmie River. Westside Hwy on Vashon island was closed due to a portion of the road sinking. Some basements flooded as China Creek in Newcastle, overflowed. Several roads around North Bend and Carnation were closed due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2010Every state in 2010This day in weather historyWarnings in Washington, December 2010
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: 273248, 273160, 273686, 273698, 273185, 273179, 273709.