Alan F. HamletAndy Wood

Dennis P. Lettenmaier

JISAO Center for Science in the Earth System Climate Impacts Group

and Department of Civil and Environmental EngineeringUniversity of Washington

October, 2006

2006 Water Resources Outlook for the Columbia River Basin

http://www.hydro.washington.edu/Lettenmaier/Presentations/2004/hamlet_2006_forecast_oct_2005.ppt

Recap of Water Year 2005

Observed Nino3.4 anomally

150000

200000

250000

300000

350000

400000

450000

-3 -2 -1 0 1 2 3 4

NINO3.4 Index Anomaly

Ap

ril-

Se

pte

mb

er

Av

era

ge

S

tre

am

flo

w

1916-2002

Historic Water Years vs January Nino 3.4 Anomalies

Red = Unconditional meanBlue = Ensemble meanBlack = 2005 Observed

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesJanuary Nino3.4 index between 0.2 and 1.2

Nat

ural

Str

eam

flow

(cf

s)

Red = Unconditional meanBlue = Ensemble meanBlack = 2005 Observed

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesJanuary Nino3.4 index between 0.2 and 1.2 and warm PDO (epochs)

Nat

ural

Str

eam

flow

(cf

s)

Red = Unconditional meanBlue = Ensemble meanBlack = 2005 Observed

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesNino3.4 index between 0.2 and 1.2 and warm PDO (interannual)

Nat

ural

Str

eam

flow

(cf

s)

ColSimReservoir

Model

VICHydrology Model

Climate Forecast

Linkage to Reservoir Models

StreamflowForecast Bias Correction

Reservoir Model

Observed Reservoir Contents

StorageEnsemble

Demand Scenarios

All Years from 1950-2003 for which J. Nino3.4 Anom. >= 0.2 AND <=1.2

Obs. SystemStorage Oct 1, 2005

October 1 Spin UpSystem Storage Forecast from SnakeSim:

Jackson LakePalisadesIsland ParkRirieAmerican FallsLake Walcott

Nino3.4 anomaly between 0.2 and 1.2 C

Demand aligned with water cond.

Act

ive

Res

ervo

ir S

tora

ge (

kaf)

Obs. SystemStorage Oct 1, 2005

Outlook for Water Year 2006

December

Winter ClimateForecasts Dominate

Hydrologic State Variables Dominate

June March

April 1 SWE (mm)

Used range: Jan3.4 >= -0.4Jan3.4 <= 0.6

150000

200000

250000

300000

350000

400000

450000

-3 -2 -1 0 1 2 3 4

NINO3.4 Index Anomaly

Ap

ril-

Se

pte

mb

er

Av

era

ge

S

tre

am

flo

w

1916-2002

Historic Water Years vs January Nino 3.4 AnomaliesRed lines show approximate range for 2006 forecast

Red = Unconditional meanBlue = Ensemble mean

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesJanuary Nino3.4 index between -0.4 and 0.6

Nat

ural

Str

eam

flow

(cf

s)

Red = Unconditional meanBlue = Ensemble mean

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesJanuary Nino3.4 index between -0.4 and 0.6 AND PDO neutral

Nat

ural

Str

eam

flow

(cf

s)

Used range: Jan3.4 >= 0.0Jan3.4 <= 0.6

Red = Unconditional meanBlue = Ensemble mean

Bias Corrected Long Range Streamflow Forecast for the Columbia River at The DallesJanuary Nino3.4 index between 0.0 and 0.6

Nat

ural

Str

eam

flow

(cf

s)

ColSim Reservoir System Storage ForecastAll Years from 1916-2003 for which J. Nino3.4 Anom. >= -0.4 AND <= 0.6

Overview of Experimental Energy-Related Forecasting Products

-3.000

-2.000

-1.000

0.000

1.000

2.000

3.000

191719221927193219371942194719521957196219671972197719821987199219972002

PNW*

CA*

Covariation of Normalized PNW and CA Hydropower Production

California and PNW hydropower resources show a strong covariance in the second half of the 20th century.

R2 =0.541

Probability of Exceedance for Spring Surplus Energy Resources in the PNW

Voisin, N., A. F. Hamlet, L. P. Graham, D. W. Pierce, T. P. Barnett, and D. P. Lettenmaier, 2005: The role of climate forecasts in western U.S. power planning, Journal of Applied Meteorology (in press).

Sys

tem

-Wid

e E

nerg

y P

rodu

ctio

n (M

MW

-hr/

mon

th)

Forecast of System-Wide Energy Production from the Colsim Reservoir ModelAll Years from 1916-2003 for which J. Nino3.4 Anom. >= -0.4 AND <= 0.6Energy targets in each year of the simulation are for WY 2000

Selected References on Compositing Techniques:

Hamlet, A.F., Lettenmaier, D.P., 1999: Columbia River Streamflow Forecasting Based on ENSO and PDO Climate Signals, ASCE J. of Water Res. Planning and Mgmt., 125 (6) : 333-341

Werner K, Brandon D, Clark M, et al., 2004: Climate index weighting schemes for NWS ESP-based seasonal volume forecasts, J. of Hydrometeorology, 5 (6): 1076-1090