FGUS76 KPQR 251638 ESFPQR HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE PORTLAND OR 835 AM PDT FRI MAR 25 2005 ...OREGON WATER SUPPLY OUTLOOK AS OF MARCH 25TH 2005... THE OUTLOOK FOR THE SPRING AND SUMMER IS FOR BELOW NORMAL WATER SUPPLY IN MOST OREGON RIVER BASINS DUE TO BELOW NORMAL PRECIPITATION AND VERY LOW SNOWPACK THIS WINTER. THE STATE FACES A VARIETY OF POTENTIAL IMPACTS DUE TO THE DRY AND WARM WEATHER EXPERIENCED MOST OF THIS WINTER...INCLUDING WATER SHORTAGES FOR SOME IRRIGATORS AND MUNICIPALITIES...INADEQUATE FLOWS AND WARM WATER TEMPERATURES FOR MIGRATING FISH...INCREASED FIRE DANGER...AND LIMITED RECREATION AT SOME RESERVOIRS DUE TO LOW WATER LEVELS. THIS HAS BEEN ONE OF THE DRIEST WINTERS IN OREGON`S RECORDED WEATHER HISTORY. CONDITIONS THUS FAR IN MARCH HAVE NOT PROVIDED ANY RELIEF TO THE THREAT OF SUMMER WATER SHORTAGES...AS MONTHLY RAINFALL HAS ONLY BEEN ABOUT HALF OF NORMAL. WHILE EVEN A WET SPRING WILL NOT BE ENOUGH TO GET SEASONAL TOTALS BACK TO NEAR NORMAL...SIGNIFICANT RAINFALL WOULD BE VERY BENEFICIAL IN MANY WAYS: INCREASED RESERVOIR STORAGE...INCREASED STREAMFLOW FOR FISHERIES INTERESTS...REDUCED IRRIGATION DEMAND...IMPROVED RANGELAND CONDITIONS...AND HIGHER MOISTURE LEVELS IN OREGON FORESTS. THE LATEST OUTLOOK FROM NOAA`S CLIMATE PREDICTION CENTER CALLS FOR ABOVE-NORMAL TEMPERATURES AND EQUAL LIKELIHOOD OF NORMAL...ABOVE-NORMAL...OR BELOW-NORMAL PRECIPITATION FOR APRIL THROUGH JUNE. FOR MORE INFORMATION...VISIT THE CPC`S WEB SITE AT WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/ (LOWER CASE). DUE TO THE DRY CONDITIONS IN OREGON...THIS PRODUCT WILL BE UPDATED TWICE MONTHLY THROUGH THE SPRING. THE NEXT UPDATE WILL BE ISSUED BY APRIL 11TH. =================================================================== ...SNOWPACK ACROSS OREGON... MOUNTAIN SNOWPACK AS OF MARCH 24TH WAS MUCH BELOW NORMAL IN ALL OREGON BASINS. IN THE NORTH OREGON CASCADES AND NORTHEAST OREGON MOUNTAINS...THE SNOWPACK IS COMPARABLE TO THE RECORD LOWS OF FEBRUARY 1977. SNOWPACK PERCENT OF NORMAL CONTINUES TO DECLINE IN ALL BASINS...AND THERE`S BEEN LITTLE SNOW ACCUMULATION AT MOST SNOW-REPORTING SITES SINCE THE FIRST OF THE YEAR. SNOTEL AND SNOWCOURSE DATA IS PROVIDED BY THE NATURAL RESOURCES CONSERVATION SERVICE. THE TABLE BELOW SHOWS THE SNOWPACK PERCENT OF NORMAL AS OF MARCH 24TH. LOCATION PCT OF NORMAL ...CENTRAL AND EASTERN OREGON... KLAMATH BASIN 35 LAKE COUNTY/GOOSE LAKE BASINS 75 HARNEY COUNTY BASINS 45 OWYHEE AND MALHEUR BASINS 45 GRANDE RONDE...POWDER...BURNT AND IMNAHA 40 UMATILLA...WALLA WALLA...WILLOW...ROCK... 25 AND LOWER JOHN DAY BASINS UPPER JOHN DAY BASIN 50 UPPER DESCHUTES AND CROOKED BASINS 40 LOWER DESCHUTES AND HOOD BASINS 25 ...WESTERN OREGON... SANDY BASIN 20 WILLAMETTE BASIN 25 ROGUE AND UMPQUA BASINS 35 =================================================================== ...PRECIPITATION ACROSS OREGON... EVEN THOUGH THERE HAS BEEN SOME WET WEATHER SINCE MID-MARCH...MONTHLY TOTALS THROUGH THE 21ST ARE STILL BELOW NORMAL...AND SEASONAL TOTALS REMAIN WELL BELOW NORMAL. THE TABLE BELOW SHOWS PRECIPITATION TOTALS IN TERMS OF PERCENT OF NORMAL FOR THE FIRST THREE WEEKS OF MARCH...AND THE PERCENT OF NORMAL FOR THE 2005 WATER YEAR THROUGH MARCH 21ST. BASIN PERCENT OF AVG FOR MAR 1ST-21ST OCT-MAR 21ST ...CENTRAL AND EASTERN OREGON... KLAMATH (OREGON ONLY) 49 69 LAKE COUNTY/GOOSE LAKE 43 87 HARNEY/MALHEUR BASIN 66 77 OWYHEE/MALHEUR 60 86 GRANDE RONDE/BURNT 34 62 UMATILLA/LOWER JOHN DAY 28 59 UPPER JOHN DAY 28 59 UPPER DESCHUTES/CROOKED 51 71 HOOD/LOWER DESCHUTES 34 48 ...WESTERN OREGON... WILLAMETTE VALLEY 34 49 ROGUE/UMPQUA 42 68 ================================================================== ...MAJOR IRRIGATION RESERVOIRS... AT THE CLOSE OF FEBRUARY...1,381,000 ACRE-FEET OF WATER WAS STORED IN 27 MAJOR IRRIGATION RESERVOIRS IN OREGON...AN INCREASE OF ABOUT 140,000 ACRE-FEET FROM FEBRUARY 1ST. THE CURRENT STORAGE REPRESENTS 65 PERCENT OF AVERAGE...AND IS 42 PERCENT OF THEIR HOLDING CAPACITY. THE CURRENT STORAGE IS 104 PERCENT OF STORAGE FOR THIS SAME TIME LAST YEAR. HOWEVER...ADDITIONAL RUNOFF FOR THE SPRING WILL BE MUCH LESS THAN LAST YEAR DUE TO THE LOW SNOWPACK...SO SEVERAL RESERVOIRS ARE LIKELY TO NOT FILL BY THE TIME DEMAND FOR IRRIGATION WATER BEGINS. RESERVOIR DATA IS PROVIDED COURTESY OF THE NATURAL RESOURCES CONSERVATION SERVICE AND THE CORPS OF ENGINEERS. ================================================================== ...CURRENT AND FORECAST STREAMFLOW... OBSERVED STREAMFLOW THUS FAR IN MARCH IS WELL BELOW NORMAL ACROSS MOST OF OREGON...WITH MANY RIVER GAGES REPORTING RECORD-LOW RIVER LEVELS FOR SEVERAL DAYS IN MARCH. RIVER LEVELS ARE COMPARABLE TO WHAT WOULD NORMALLY BE OBSERVED IN JULY OR AUGUST. FORECAST STREAMFLOW VOLUMES FOR THE SPRING AND SUMMER ARE BELOW NORMAL FOR ALL OREGON BASINS. THE FORECAST FOR THE COLUMBIA RIVER AT THE DALLES IS BELOW NORMAL AND REFLECTS CONDITIONS ACROSS THE COLUMBIA BASIN. THE FORECAST VOLUME FOR THE DALLES AND MOST OREGON BASINS HAVE BEEN IN CONTINUAL DECLINE WITH EACH FORECAST UPDATE AS THE DRY WEATHER HAS PERSISTED THROUGH MUCH OF THE NORMAL WET SEASON. THE FOLLOWING TABLE SUMMARIZES THE FORECASTS FOR SELECTED RIVERS... UPDATED MARCH 18TH. THESE FORECASTS ARE BASED ON OBSERVED PRECIPITATION AND SNOWPACK AND ASSUME 70 PERCENT OF NORMAL PRECIPITATION FOR THE REST OF MARCH...80 PERCENT OF NORMAL FOR THE FIRST HALF OF APRIL...AND NORMAL PRECIPITATION THEREAFTER. FORECASTS FOR THE KLAMATH BASIN ARE PRODUCED BY THE CALIFORNIA-NEVADA RIVER FORECAST CENTER AND WERE LAST UPDATED MARCH 15TH. W A T E R S U P P L Y F O R E C A S T S ...FORECASTS AND AVERAGES ARE IN THOUSANDS OF ACRE-FEET... ...`%` IS PERCENT OF AVERAGE BASED ON 1971 - 2000 NORMALS... STREAM AND STATION PERIOD FORECAST % AVERAGE COLUMBIA RIVER THE DALLES JAN-JUL 67700.0 63 107300. OWYHEE RIVER OWYHEE RES INFLOW MAR-JUL 200.0 33 613. MALHEUR RIVER NEAR DREWSEY MAR-JUL 36.0 33 110. N.F. MALHEUR RIVER BEULAH RES INFLOW MAR-JUL 30.0 37 81. BURNT RIVER NEAR HEREFORD MAR-JUL 14.8 29 51. POWDER RIVER NEAR SUMPTER MAR-JUL 28.0 40 70. IMNAHA RIVER IMNAHA MAR-JUL 124.0 41 301. GRANDE RONDE RIVER LA GRANDE APR-JUL 80.0 43 184. TROY APR-JUL 730.0 57 1274. UMATILLA RIVER NEAR GIBBON APR-JUL 35.0 48 73. PENDLETON APR-JUL 59.0 40 149. S.F. WALLA WALLA RIVER NEAR MILTON APR-JUL 36.0 68 53. M.F. JOHN DAY RIVER RITTER APR-JUL 53.0 43 123. N.F. JOHN DAY RIVER NEAR MONUMENT APR-JUL 240.0 40 597. JOHN DAY RIVER SERVICE CREEK MAR-SEP 375.0 33 865. DESCHUTES RIVER BENHAM FALLS APR-SEP 380.0 72 528. CROOKED RIVER PRINEVILLE RES INFLOW MAR-JUL 59.0 32 184. OCHOCO CREEK OCHOCO RES INFLOW MAR-JUL 11.6 32 35. MCKENZIE RIVER NEAR VIDA APR-SEP 735.0 61 1300. S. SANTIAM RIVER WATERLOO APR-SEP 345.0 59 587. N. SANTIAM RIVER MEHAMA APR-SEP 485.0 58 834. WILLAMETTE RIVER SALEM APR-SEP 2640.0 55 4804. CLACKAMAS RIVER ESTACADA APR-SEP 400.0 53 748. N. UMPQUA RIVER LEMOLO LK INFLOW APR-SEP 92.0 61 151. ROGUE RIVER GOLD RAY APR-SEP 455.0 51 889. CHEWAUCAN RIVER NEAR PAISLEY MAR-JUL 46.0 52 89. SILVIES RIVER NEAR BURNS APR-SEP 72.0 72 99. WILLIAMSON RIVER BELOW SPRAGUE APR-SEP 180.0 47 385. SPRAGUE RIVER NEAR CHILOQUIN APR-SEP 110.0 48 230. KLAMATH RIVER UPPER LAKE INFLOW APR-SEP 210.0 41 515. THESE FORECASTS ARE SELECTED FROM THOSE PREPARED BY: NATIONAL WEATHER SERVICE, NATURAL RESOURCE CONSERVATION SERVICER, AND B.C. HYDRO AND POWER AUTHORITY. FOR VARIOUS PROJECT INFLOWS, THE FORECASTS HAVE BEEN COORDINATED WITH THE U.S. ARMY CORP OF ENGINEERS AND THE U.S. BUREAU OF RECLAMATION. FOR FURTHER DETAILS ON THE WATER SUPPLY FORECAST AND CONTIGENCY FORECASTS BASED ON DIFFERENT SCENARIOS FOR FUTURE PRECIPITATION...VISIT WWW.NWRFC.NOAA.GOV/WATER_SUPPLY/WATER_SUPPLY.CGI (LOWER CASE) AND WWW.WRH.NOAA.GOV/CNRFC/WATER_SUPPLY.PHP (LOWER CASE). BRYANT $$ WEATHER.GOV/PORTLAND