End of March heavy rainfall on melting snowpack along the east slopes of the Washington Cascades caused flooding along numerous streams in western Kittitas and Yakima counties. 69 inches in Cle Elum.
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 PDT wrote it up.
End of March heavy rainfall on melting snowpack along the east slopes of the Washington Cascades caused flooding along numerous streams in western Kittitas and Yakima counties. Reported rainfall included 2.5 inches in Easton and .69 inches in Cle Elum. Water was over the roads in 12 locations in upper Kittitas County and resulted in washouts of shoulders and some 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 Pendleton, OR wrote its last area forecast discussion before the first event at Mar 31, 7:20 PM PST, 4 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 820 PM PDT THU MAR 31 2011 .UPDATE...WINDS ARE DECREASING NICELY THIS EVENING WITH THE LOSS OF SURFACE HEATING AND MIXING. WILL LET THE WIND ADVISORY EXPIRE AT 9 PM AS SCHEDULED FOR THE WASHINGTON LOWER COLUMBIA BASIN. THE ONLY OTHER MAIN CONCERNS TONIGHT ARE HYDROLOGY ISSUES WHICH I WILL DISCUSS BELOW. THE FORECAST AREA WILL BE UNDER THE INFLUENCE OF A RATHER FLAT UPPER RIDGE FOR THE REST OF TONIGHT AND FRIDAY WITH QUITE MILD TEMPERATURES. MANY LOW ELEVATION LOCATIONS WILL SEE TEMPERATURES IN THE 60S TO AROUND 70 FRIDAY AFTERNOON...WITH 50S TO LOWER 60S IN THE MOUNTAINS. ANOTHER WEATHER SYSTEM WILL MOVE INTO THE REGION FRIDAY NIGHT AND ON SATURDAY BRINGING COOLER TEMPERATURES AND ANOTHER CHANCE FOR PRECIPITATION...WITH POSSIBLY MORE SNOW FOR THE MOUNTAINS. WILL NEED TO WATCH THAT SITUATION CLOSELY AS THAT EVENT UNFOLDS. WILL UPDATE THE FORECAST TO REFRESH THE EVENING WORDING AND TO REMOVE THE WIND ADVISORY. 88 && .AVIATION...06Z TAFS...VFR CONDITIONS ARE EXPECTED OVERNIGHT AND ON FRIDAY WITH MUCH LIGHTER WINDS EXPECTED. WIND SPEEDS WILL RANGE FROM 5 TO 10 KTS AT ALL TAF LOCATIONS ON FRIDAY. 88 && .HYDROLOGY...RECENT MODERATE TO HEAVY AMOUNTS OF RAIN ALONG WITH RAPIDLY MELTING SNOW HAS CAUSED SIGNIFICANT RISES ON RIVERS AND STREAMS IN WESTERN PORTIONS OF THE FORECAST AREA AND ALSO IN A PORTION OF THE NORTHEAST MOUNTAINS. IN PARTICULAR THERE IS A FLOOD WARNING IN EFFECT FOR 4 MAIN STEM RIVERS IN THE YAKIMA RIVER BASIN WITH NUMEROUS OTHER SMALLER RIVERS AND STREAMS RUNNING NEAR OR ABOVE BANKFULL LEVELS AND CAUSING MINOR FLOODING. RIVERS ARE EXPECTED TO CREST ON FRIDAY AND THEN WILL RECEDE FRIDAY NIGHT AND SATURDAY AS SNOW LEVELS LOWER WITH LESSENING SLOW SNOW MELT. ADDITIONAL PRECIPITATION DURING THE WEEKEND COULD CAUSE RISES AGAIN BY SUNDAY...BUT THE COOLER TEMPERATURES AND LOWER SNOW LEVELS WILL HELP TO DAMPEN THE POTENTIAL RISES ON RIVERS AND STREAMS LATER IN THE WEEKEND. 88 && .PREV DISCUSSION... /ISSUED 155 PM PDT THU MAR 31 2011/ SHORT TERM...TONIGHT THROUGH SUNDAY...A BROAD UPPER LEVEL RIDGE IS OVER THE PACIFIC NORTHWEST. THERE IS ENOUGH MOISTURE MOVING THROUGH THE RIDGE FOR CONSIDERABLE CLOUDINESS...BUT NOT ENOUGH LIFT FOR WIDESPREAD PRECIPITATION. UPSLOPE CONDITIONS WILL CREATE SOME SHOWERS IN THE BLUE MOUNTAINS AND ALONG THE CASCADES TONIGHT AND FRIDAY. THE CORE OF THE JETSTREAM IS LOCATED IN CANADA...BUT IT IS STRONG ENOUGH THAT 250 MB WINDS OVER EASTERN WASHINGTON ARE 90-100 KTS. WINDS AT 700 MB ARE45-60 KT. SOME OF THESE HIGHER WINDS ALOFT ARE MIXING TO THE SURFACE IN THE TRI CITIES NORTH AND EASTWARD IN THE LOWER COLUMBIA BASIN. A WIND ADVISORY HAS BEEN ISSUED FOR THIS AREA. WINDS WILL DECREASE OVERNIGHT AS WINDS ALOFT AND SURFACE PRESSURE GRADIENTS DECREASE. ANOTHER SYSTEM WILL APPROACH THE COAST FRIDAY NIGHT AND MOVE ACROSS THE CASCADES SATURDAY MORNING. THIS WILL BRING A CHANCE OF PRECIPITATION TO EASTERN WASHINGTON AND OREGON. SNOW LEVELS WILL BE 4500-7000 FEET FRIDAY...THEN DROP OVERNIGHT TO 3000-5000 FEET. WITH THE COLDER AIR ALOFT RAIN WILL CHANGE TO SNOW IN THE MOUNTAINS. AN UPPER LEVEL LOW AND ASSOCIATED TROUGH WILL MOVE THROUGH ON SATURDAY. THIS WILL BRING HIGH POPS SATURDAY MORNING...THEN RAIN SHADOWING WILL DEVELOP IN THE YAKIMA AND KITTITAS VALLEYS...LOWER COLUMBIA BASIN...AND THE DESCHUTES PLATEAU BY SATURDAY AFTERNOON. POPS WILL DECREASE MORE SATURDAY NIGHT AND SUNDAY AS DRIER AIR AND NORTHERLY FLOW MOVES IN BEHIND THE TROUGH. UPSLOPE CONDITIONS WILL KEEP MOUNTAIN SHOWERS SATURDAY NIGHT AND SUNDAY. COONFIELD LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...THE REGION WILL BE UNDER THE INFLUENCE OF A TRANSITIONAL RIDGE THROUGH MONDAY NIGHT WITH JUST LOW CHANCES FOR SHOWERS ALONG THE WASHINGTON CASCADE EAST SLOPES AND NORTHEAST MOUNTAINS. AFTERWARDS A LARGE SCALE TROUGH WILL BEGIN TO INFLUENCE THE INTERIOR NW WITH INCREASING CHANCES FOR RAIN AND HIGH MOUNTAIN SNOW. THAT BEING SAID THE LATEST ECMWF BRINGS THE TROUGH IN FROM A MUCH DRIER NWLY AND PROGRESSIVE TRAJECTORY THAN THE GFS. THEREFORE HAVE HELD POPS LOWER THAN WHAT THE 12Z GFS MODEL WOULD SUGGEST. THERE WILL BE THE POTENTIAL FOR PERIODS OF AT LEAST BREEZY CONDITIONS EARLY NEXT WEEK DEPENDING ON THE TIMING OF FRONTAL PASSAGES. TEMPERATURES WILL BE NEAR NORMAL AND SNOW LEVELS WILL START OUT HIGH BEFORE LOWERING TO 4-5 THOUSAND FEET BY MID WEEK.78 HYDROLOGY...WE CONTINUE TO SEE FLOWS INCREASE ON THE EAST SLOPES OF THE CASCADES WITH SMALL STREAM FLOODING IN WESTERN KITTITAS AND YAKIMA COUNTIES. THE MAIN STEM NACHES RIVER IS NO LONGER EXPECTED TO REACH FLOOD STAGE WITH THE FLOOD WATCH CANCELLED. THE YAKIMA RIVER IS CONTINUING TO RISE AND FLOOD WARNING MAY BE NEEDED OVERNIGHTS. MOST SMALL STREAM AND CREEKS WILL BE PEAKING TONIGHT AND SLOWLY DECREASE OVER THE NEXT FEW DAYS. ML && .PRELIMINARY POINT TEMPS/POPS... PDT 44 69 43 50 / 10 10 50 70 ALW 49 66 48 55 / 10 10 50 70 PSC 46 68 47 57 / 0 0 30 60 YKM 40 67 40 57 / 0 0 30 50 HRI 43 71 45 57 / 0 0 30 60 ELN 42 63 41 52 / 0 10 40 50 RDM 40 69 38 46 / 0 0 40 70 LGD 46 65 39 49 / 20 10 50 80 GCD 40 68 42 48 / 10 10 30 70 DLS 43 67 45 56 / 10 10 50 60 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && THREAT INDEX FRIDAY : YELLOW SATURDAY : GREEN SUNDAY : GREEN GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES. YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON 88/88/78
HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE PENDLETON OR
1130 PM PDT THU MAR 31 2011
CORRECTED TO ADD FLOODING INFORMATION
ORZ041-042-044-049-050-502-503-505>509-WAZ024-026>030-520-521-
011415-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-WALLOWA COUNTY-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-JOHN DAY BASIN-OCHOCO-
JOHN DAY HIGHLANDS-
FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON-
FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON-
EAST SLOPES OF THE OREGON CASCADES-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS OF WASHINGTON-
EAST SLOPES OF THE WASHINGTON CASCADES-SIMCOE HIGHLANDS-
1130 PM PDT THU MAR 31 2011
THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.
.DAY ONE...TONIGHT
FLOODING
EAST SLOPES OF THE WASHINGTON CASCADES
HIGH PRESSURE ALOFT WILL PROVIDE DRIER AND MILD CONDITIONS TONIGHT
AND FRIDAY WITH LIGHT WINDS.
SNOW MELT RUNOFF AND RECENT RAINFALL HAVE RESULTED IN SIGNIFICANT
RISES ON MANY RIVERS AND STREAMS...PARTICULARLY ALONG THE EAST
SLOPES OF THE WASHINGTON CASCADES. AN AREAL SMALL STREAM FLOOD
WARNING IS IN EFFECT FOR WESTERN KITTITAS COUNTY...AND AN AREAL
FLOOD ADVISORY IS IN EFFECT FOR YAKIMA COUNTY. FLOOD WARNINGS HAVE
BEEN POSTED FOR THE YAKIMA RIVER AND THE NACHES RIVER. FOR THE
LATEST STATEMENTS...REFER TO THE NWS PRODUCTS PDXFLWPDT (SMALL
STREAM FLOOD WARNING AND RIVER FLOOD WARNINGS) AND PDXFLSPDT (FLOOD
ADVISORY). THE HYDROLOGIC PRODUCT...PDXRVSPDT...PROVIDES DETAILS ON
OTHER RIVERS RUNNING HIGH IN THE COUNTY WARNING AREA.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
FLOODING FRIDAY
EAST SLOPES OF THE WASHINGTON CASCADES
SNOW SATURDAY
NORTHWEST BLUE MOUNTAINS OF WASHINGTON, GRANDE RONDE VALLEY,
WALLOWA COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN
BLUE MOUNTAINS OF OREGON
A MID/UPPER LEVEL PACIFIC TROUGH WILL PUSH A COLD FRONT THROUGH THE
FORECAST AREA SATURDAY AND BRING RAIN AND MOUNTAIN SNOW TO THE
FORECAST AREA. SNOW LEVELS WILL DROP SATURDAY AFTERNOON AS THE COLD
FRONT EXITS INTO IDAHO. SNOW LEVELS WILL LOWER TO AROUND 3500-4000
FEET BY LATE SATURDAY AFTERNOON AND THEN CONTINUE TO LOWER SATURDAY
NIGHT TO AROUND 2000-2500 FEET IN THE MOUNTAINS OF EASTERN OREGON
AND SOUTHEAST WASHINGTON. THESE AREAS MAY RECEIVE LATE SEASON SNOW
ACCUMULATIONS OF SEVERAL INCHES...WHICH COULD MEET THE LATE SEASON
WINTER WEATHER ADVISORY CRITERIA FOR SNOW IN THE BLUE MOUNTAINS AND
IN THE GRANDE RONDE AND WALLOWA VALLEYS.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED FOR FLOODING ALONG THE EAST
SLOPES OF THE WASHINGTON CASCADES.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:
WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML
ALL LETTERS IN THE ABOVE URL ARE LOWER CASE.The Seattle radar (KATX), 139 km away, was scanning. The volume nearest the first event began at 08:03 UTC.
5 flood, 1 flash flood. Local standard time, as filed.
Flooding continued from March 31 with the gage at Easton cresting at 1 foot above flood stage.
Continuing from March 31, the river gage at Horlick crested at .5 feet above flood stage.
Continuing from March 31, the river gage at Umtanum crested at .6 feet above flood stage.
Continuing from March 31, the river gage at Naches crested at .2 feet above flood stage.
The river gage at Parker crested 1.3 feet above flood stage.
The river gage at Kiona crested at 1.3 feet above flood stage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2011Every state in 2011This day in weather historyWarnings in Washington, April 2011
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: 292689, 292695, 292698, 292702, 292699, 292700.