Rain caused flash floods and mudslides in several locations and closed a 24-mile section of the North Cascades Highway for several days. Also heavy rain caused a sinkhole which damaged a road in Burien.
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.
Rain caused flash floods and mudslides in several locations and closed a 24-mile section of the North Cascades Highway for several days. Also heavy rain caused a sinkhole which damaged a road in Burien.
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 Sep 4, 8:07 PM PST, 3 hours 53 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
907 PM PDT WED SEP 4 2013
.SYNOPSIS...A STRONG OFFSHORE LOW PRESSURE SYSTEM WILL MOVE OVER
OREGON LATE THURSDAY AND THEN NORTH OVER THE CENTRAL PART OF
WASHINGTON ON FRIDAY. THIS STORM SYSTEM WILL BRING THE POTENTIAL FOR
EXCESSIVE RAINFALL OVER PARTS OF THE AREA...ESPECIALLY THURSDAY
NIGHT AND FRIDAY. THE LOW WILL SHIFT SLOWLY EAST DURING THE DAY
SATURDAY FOR GRADUALLY IMPROVING CONDITIONS FOLLOWED BY DRY WEATHER
ON SUNDAY.
&&
.SHORT TERM...A MOIST AND RELATIVELY UNSTABLE AIR MASS WILL CONTINUE
OVER THE AREA THROUGH TONIGHT FOR A CONTINUED RISK OF SHOWERS AND A
CHANCE ALBEIT A LESSER ONE FOR TSTMS.
THE VIGOROUS UPPER LEVEL LOW OVER THE OFFSHORE WATERS WILL SHIFT
EAST OVER OREGON LATE IN THE DAY THURSDAY BEFORE LIFTING NORTH INTO
WASHINGTON ON FRIDAY. AS THE LOW TRACKS INTO OREGON
THURSDAY...DIFFLUENT FLOW ALOFT OVER WASHINGTON WILL HELP SPREAD
SHOWERS INTO THE AREA FROM THE SOUTH DURING THE MORNING AS WELL AS
THE THREAT OF THUNDERSTORMS...ESPECIALLY OVER THE INTERIOR.
THE CONVECTIVE RAINFALL WILL TRANSITION OVER TO STRATIFORM RAIN
LATER THURSDAY EVENING AS A DEFORMATION ZONE SETS UP OVER THE
CENTRAL AND EASTERN PART OF THE CWA THURSDAY NIGHT INTO FRIDAY
MORNING. MESOSCALE MODELS CONSISTENTLY PRODUCING SIGNIFICANT
RAINFALL AMOUNTS...ESPECIALLY FOR THIS TIME OF YEAR. STORM TOTAL
PRECIPITATION AMOUNTS RANGING BETWEEN 1 AND 2 INCHES WITH MUCH
HIGHER AMOUNTS POSSIBLE LOCALLY ESPECIALLY WITH HIGHER RAIN RATES
ASSOCIATED WITH CONVECTIVE RAIN. URBAN AND SMALL STREAM FLOODING
REMAINS A CONCERN WITH THE POSSIBILITY OF LANDSLIDES ESPECIALLY IN
STEEP MOUNTAINOUS TERRAIN.
THE UPPER LOW WILL SLOWLY MOVE NORTH AND EAST INTO CENTRAL
WASHINGTON ON FRIDAY...HELPING SPREAD THE RAIN OVER WESTERN
WASHINGTON FURTHER NORTH BEFORE PULLING BACK TO THE EAST LATE FRIDAY
AFTERNOON. PRECIPITATION WILL BECOME MORE SHOWERY FRIDAY NIGHT AS
THE LOW CONTINUES EAST.
.LONG TERM...THE TREND IN THE FORECAST CONTINUES TO BE DRYING
SATURDAY AND SUNDAY AS AN UPPER LEVEL RIDGE BEGINS TO BUILDS ALONG
THE COAST INSIDE OF 130W. SATURDAY WILL SEE A LINGERING CHANCE OF
SHOWERS AS THE LAST EFFECTS OF THE UPPER LEVEL LOW SHIFT EAST. THE
UPPER RIDGE WILL BECOME ESTABLISHED OVER THE EASTERN PACIFIC WITH
NORTHWESTERLY FLOW ALOFT...DRY WEATHER AND ABOVE NORMAL DAYTIME
TEMPS.
&&
.HYDROLOGY...
MODELS CONTINUED TO ADVERTISE THE POTENTIAL FOR EXCESSIVE
RAINFALL OVER THE AREA THU THROUGH FRI. IT STILL LOOKS LIKE THE
EASTERN PART OF THE FORECAST AREA...OLYMPIC RANGE EASTWARD...
HAS THE HIGHEST THREAT FOR SIGNIFICANT RAINFALL. GENERALLY...1
TO 2 INCHES OF RAIN IS POSSIBLE...WITH LOCAL AMOUNTS UP 4 INCHES
IN THE CASCADES...DURING THE 36-HOUR PERIOD ENDING 5 PM PDT FRI.
A FEW OF THE NUMERICAL WEATHER MODELS WERE WETTER AND INDICATED
AMOUNTS OF 2 TO 3 INCHES...WITH LOCAL AMOUNTS UP TO 6 INCHES.
&&
.AVIATION...AN UPPER LEVEL LOW JUST OFF THE OREGON COAST WILL SHIFT
INLAND OVER WA AND OREGON THURSDAY NIGHT. SOUTHERLY FLOW ALOFT WILL
TURN MORE EASTERLY THURSDAY. THE BAND OF CLOUDS THAT EXTENDS FROM SW
BRITISH COLUMBIA SOUTH MORE OR LESS ALONG I-5 TO NORTHERN CALIFORNIA
WILL DEVELOP THROUGH THURSDAY MORNING WITH AREAS OF RAIN DEVELOPING.
THIS FRONTAL BOUNDARY WILL BE ENHANCED BY SHOWERS OR RAIN BANDS
DEVELOPING OVER EASTERN WA AND EASTERN OREGON THURSDAY THAT...AS THE
FLOW TURNS FROM SOUTHERLY TO MORE EASTERLY...FEED INTO THE FRONTAL
BAND. CONDITIONS WILL DETERIORATE THURSDAY AND THURSDAY NIGHT WITH
LOWERING CIGS AND POOR VSBY.
KSEA...LIGHT AND VARIABLE WIND...GRADIENTS ARE PRETTY FLAT. RAIN
WILL DEVELOP THURSDAY AND CONDITIONS WILL DROP BY AFTERNOON. THE
HEAVIEST RAIN MAY HOLD OFF TIL THURSDAY NIGHT.
&&
.MARINE...THERE IS A 1016 MB LOW OVER THE OREGON OFFSHORE WATERS BUT
THAT LOW WILL DISSIPATE AS IT MOVES INTO SW OREGON THURSDAY MORNING.
THE MAIN FEATURE IS LOW PRESSURE INLAND AND PRESSURES HAVE BEEN
FALLING EAST OF THE CASCADES AND ARE NOW STARTING TO DROP OVER
WESTERN OREGON AS A FRONTAL SYSTEM DEVELOPS OVER THE AREA. THE LOW
PRESSURE INLAND WILL CONTINUE TO DEVELOP THROUGH THURSDAY AND AS
PRESSURES FALL OVER THE REGION AND RISE OUTSIDE OF 130W ONSHORE FLOW
INTO WESTERN WA WILL INCREASE.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCH IN EFFECT FOR MUCH OF THE AREA FROM THURSDAY
AFTERNOON THROUGH FRIDAY AFTERNOON.
PZ...NONE.
&&
WWW.WEATHER.GOV/SEATTLE
FOR THE GRAPHICAL AFD...VISIT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTMLThe Seattle radar (KATX), 110 km away, was scanning. The volume nearest the first event began at 07:58 UTC.
1 flash flood, 1 heavy rain. Local standard time, as filed.
Rain caused flash floods and mudslides in several locations and closed a 24-mile section of the North Cascades Highway.
Heavy rain caused a sinkhole which damaged a road in Burien.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2013Every state in 2013This day in weather historyWarnings in Washington, September 2013
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: 476514, 476515.