Flood Potential Outlook
Issued by NWS Portland, OR

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WATER SUPPLY OUTLOOK
NATIONAL WEATHER SERVICE PORTLAND OR
515 PM PDT MONDAY JUNE 6 2016

...OREGON WATER SUPPLY OUTLOOK AS OF JUNE 6TH 2016...

THE WATER SUPPLY FORECAST FOR THE SUMMER OF 2016 IS BELOW-AVERAGE
FOR MUCH OF OREGON, ALTHOUGH SOME BASINS IN SOUTHWESTERN AND NORTH-
CENTRAL OREGON ARE FORECAST TO BE NEAR AVERAGE.  WATER SUPPLY VOLUME
FORECASTS FOR APRIL-SEPTEMBER HAVE TRENDED LOWER SINCE MARCH DUE TO
EARLIER-THAN-NORMAL SNOWMELT AND BELOW-AVERAGE SPRING PRECIPITATION.

REFER TO THE SECTIONS BELOW AND THE LINKS PROVIDED FOR DETAILS
REGARDING SNOWPACK, PRECIPITATION, RESERVOIR CONDITIONS, AND WATER
SUPPLY FORECASTS FOR INDIVIDUAL BASINS.

NOAA`S CLIMATE OUTLOOKS FOR JUNE THROUGH AUGUST INDICATE ABOVE-
AVERAGE TEMPERATURES ARE LIKELY THROUGH THE SUMMER. SUMMER
PRECIPITATION TOTALS ARE LIKELY NEGLIGIBLE IN THEIR EFFECT ON WATER
SUPPLY CONDITIONS. EL NINO CONDITIONS HAVE TRANSITIONED TO ENSO-
NEUTRAL, AND THERE IS A HIGH LIKELIHOOD OF LA NINA CONDITIONS FOR
THE FALL AND WINTER OF 2016-17. FOR MORE ABOUT SEASONAL OUTLOOKS
FROM THE CLIMATE PREDICTION CENTER, VISIT WWW.CPC.NCEP.NOAA.GOV.

PRECIPITATION THIS PAST WINTER ALLEVIATED DROUGHT CONDITIONS FOR
MUCH OF THE STATE, ESPECIALLY IN SOUTHERN OREGON, WHERE MULTI-YEAR
DROUGHT PERSISTED THROUGH 2015. HOWEVER, THE WARM AND DRY SPRING HAS
RENEWED CONCERNS ABOUT POTENTIAL DROUGHT IMPACTS THIS SUMMER,
ESPECIALLY LOW STREAMFLOW ON RIVERS WITH NO RESERVOIR REGULATION.
STREAMFLOW FOR MANY RIVERS IS AS LOW OR EVEN LOWER THAN THIS TIME
LAST YEAR. THE U.S. DROUGHT MONITOR HIGHLIGHTS CONTINUED MODERATE
DROUGHT (D1) CONDITIONS FOR SOUTH-CENTRAL AND SOUTHEAST OREGON, WITH
ABNORMALLY DRY (D0) FOR MOST OF NORTHERN OREGON. VISIT DROUGHT.GOV
AND WWW.OREGON.GOV/OWRD/PAGES/WR/DROUGHT.ASPX FOR DETAILS.

THIS IS THE FINAL WATER SUPPLY OUTLOOK FOR THE SEASON.  LOOK FOR
DROUGHT INFORMATION SUMMARIES TO BE ISSUED ON A MONTHLY BASIS
STARTING IN JULY GIVEN THE LIKELY PERSISTENCE OF DROUGHT CONDITIONS
INTO THE SUMMER.

============================================================
SNOWPACK AROUND OREGON

SEASONAL SNOWPACK PEAKED NEAR AVERAGE IN MARCH, BUT AS OF EARLY
JUNE, THE ONLY SNOW REMAINING WAS ON THE HIGHEST PEAKS IN THE
CASCADES AND WALLOWAS. THE SNOWPACK MELTED VERY RAPIDLY, WITH MOST
OF IT GONE BY EARLY MAY.

REFER TO THE FOLLOWING LINKS FOR MORE INFORMATION.

NOAA`S NATIONAL WEATHER SERVICE - NORTHWEST RIVER FORECAST CENTER
WWW.NWRFC.NOAA.GOV/SNOW/

USDA - NATURAL RESOURCES CONSERVATION SERVICE
WWW.NRCS.USDA.GOV/WPS/PORTAL/NRCS/MAIN/OR/SNOW/

============================================================
PRECIPITATION AND TEMPERATURES ACROSS OREGON

2016 WATER YEAR PRECIPITATION IS ABOVE-AVERAGE ACROSS THE STATE,
ESPECIALLY SO IN WESTERN AND SOUTHEASTERN OREGON. PRECIPITATION
TOTALS (OCTOBER 1 THROUGH JUNE 1) RANGE FROM 90 TO 115 PERCENT OF
AVERAGE. MONTHLY TOTALS FOR MAY WERE ONLY 30 TO 50 PERCENT OF
AVERAGE IN WESTERN OREGON AND 70 TO 90 PERCENT OF AVERAGE IN CENTRAL
AND EASTERN OREGON.

FOR THE WATER YEAR, TEMPERATURES HAVE BEEN ABOVE-AVERAGE EVERY
MONTH, EXCEPT NOVEMBER AND DECEMBER, AND HAVE BEEN NOTABLY WARM
SINCE FEBRUARY. TEMPERATURES IN MAY WERE 1 TO 3 DEGREES ABOVE
AVERAGE, WITH A WIDE RANGE OF DAYS MUCH-ABOVE AND MUCH-BELOW AVERAGE.

VISIT THE FOLLOWING LINKS FOR MORE DETAILS ON PRECIPITATION AND
TEMPERATURES.

NOAA`S NATIONAL WEATHER SERVICE - NORTHWEST RIVER FORECAST CENTER
WWW.NWRFC.NOAA.GOV/WATER_SUPPLY/WY_SUMMARY/WY_SUMMARY.PHP

NOAA`S NATIONAL WEATHER SERVICE - CALIFORNIA-NEVADA RIVER FORECAST
CENTER (KLAMATH BASIN ONLY)
WWW.CNRFC.NOAA.GOV/WATER_RESOURCES_UPDATE.PHP

============================================================
RESERVOIRS

RESERVOIR STORAGE INCREASED SIGNIFICANTLY DURING MARCH AND APRIL BUT
DIDN`T CHANGE MUCH IN MAY. AS OF EARLY JUNE, RESERVOIRS HAVE 45 TO
95 PERCENT OF AVERAGE STORAGE FOR THIS TIME OF YEAR. MANY RESERVOIRS
HAVE BEGUN RELEASES TO SUPPORT IRRIGATION DISTRICTS AND IN-STREAM
REQUIREMENTS DOWNSTREAM. OWYHEE, THE LARGEST IRRIGATION RESERVOIR IN
OREGON, 62 PERCENT OF AVERAGE STORAGE AS OF EARLY JUNE AND HAS
STARTED DRAWDOWN TO SUPPORT IRRIGATION REQUIREMENTS DOWNSTREAM IN
EASTERN OREGON. MOST FLOOD CONTROL RESERVOIRS IN WESTERN OREGON DID
NOT FILL TO FULL-POOL LEVELS DUE TO THE DRY WEATHER IN APRIL AND
MAY.

RESERVOIR DATA IS PROVIDED BY THE NATURAL RESOURCES CONSERVATION
SERVICE, THE BUREAU OF RECLAMATION, AND THE US ARMY CORPS OF
ENGINEERS.

VISIT THE FOLLOWING LINKS FOR ADDITIONAL RESERVOIR INFORMATION:

WWW.WCC.NRCS.USDA.GOV/BASIN.HTML
WWW.USBR.GOV/PN/HYDROMET/SELECT.HTML
WWW.NWD-WC.USACE.ARMY.MIL/NWP/TEACUP/WILLAMETTE/


============================================================
CURRENT AND FORECAST STREAMFLOW

OBSERVED STREAMFLOW IN MAY WAS NEAR-AVERAGE IN CENTRAL AND EASTERN
OREGON AND BELOW-AVERAGE IN WESTERN OREGON, ESPECIALLY SO FOR
COASTAL RIVERS IN NORTHWESTERN OREGON, WHERE FLOWS IN MAY 2016 WERE
VERY SIMILAR TO THE LOW CONDITIONS IN MAY 2015.

VISIT WATERWATCH.USGS.GOV FOR MORE DETAILS ON OBSERVED STREAMFLOW.

APRIL-SEPTEMBER RUNOFF VOLUME FORECASTS FOR OREGON BASINS RANGE FROM
30 TO 90 PERCENT OF AVERAGE, WITH THE HIGHEST VALUES GENERALLY IN
CENTRAL AND SOUTHWESTERN OREGON. WATER SUPPLY FORECASTS HAVE
DECREASED SIGNIFICANTLY SINCE MARCH. PARTICULAR AREAS OF CONCERN FOR
LOW SUMMER STREAMFLOW INCLUDE NORTH COASTAL RIVERS, THE WILLAMETTE
BASIN, AND SOME RIVERS IN NORTHEAST OREGON.

THE FORECAST FOR THE COLUMBIA RIVER AT THE DALLES, WHICH IS A GOOD
INDEX OF CONDITIONS ACROSS THE COLUMBIA BASIN, IS 93% OF AVERAGE FOR
APRIL-SEPTEMBER, A DECREASE OF 6% FROM THE FORECAST IN EARLY MAY.

VISIT THE FOLLOWING LINKS FOR MORE DETAILS ON BASIN-SCALE WATER
SUPPLY FORECASTS:

NOAA`S NATIONAL WEATHER SERVICE - NORTHWEST RIVER FORECAST CENTER
WWW.NWRFC.NOAA.GOV/WS/

USDA - NATURAL RESOURCES CONSERVATION SERVICE
WWW.WCC.NRCS.USDA.GOV/WSF/

BRYANT
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