West-wide and East-wide Seasonal Hydrologic Prediction Systems

PI (West): Dennis P. Lettenmaier (U. of Washington)PI (East): Eric F. Wood (Princeton University)

Primary Contributors: Andy Wood (UW)Lifeng Luo (Princeton)

Others: Nathalie Voisin (UW), Ted Bohn (UW), Ali Akanda (UW), George Thomas (UW), Justin Sheffield (Princeton)

NOAA CPPA Principal Investigator’s MeetingAug.14-16, 2006

Tucson, AZ

1)Science Questions and Objectives

2)Background on both forecasting systems

3)Applications areas- seasonal forecasting

-- climate forecasts-- initial conditions estimates

- shorter lead forecasting (15 day)- drought monitoring

4)External Interactions

Topics

CPPA vision: improve operational intraseasonal to interannual climate prediction and hydrological applications.

CPPA land-atmosphere interaction science objectives: (1) improve understanding and simulation of coupled land-atmosphere

processes through observation, data analysis, and modeling studies; (2) determine the influence of land-atmosphere processes on intra-seasonal to

interannual climate predictability; and (3) use this knowledge to advance operational forecasts, monitoring, and

analysis.

The two projects target the CPPA goal of improving the scientific basis for operational hydrologic forecasts through use of NOAA (and other) climate forecasts and data products.

Governing CPPA Science Objectives

The west/east hydrologic forecast systems are founded on almost a decade of NOAA funded development

LDAS project VIC development, implementation for LDAS region, and 50 year

retrospective (Mitchell et al., 2004; Maurer et al., 2002)

OGP GCIP/GAPP developed approaches for using NCEP seasonal climate model

forecasts (Ohio River basin and East Coast)

CDEP/ARCS extension of retrospective simulations to 1915; expansion of

forecast activities to westwide domains; exploration of shorter lead forecasts

NOAA OHD offered a letter of support for the current projectNASA funding has also played a role (NSIPP/GMAO)

Background

West-wide System

2004

2005

2006

West Side (Washington)

East Side (Princeton)

East-wide System

Research Objectives

1) To understand the predictability of the hydrological cycle at medium range and seasonal-to-interannual timescales

2) To develop the seasonal / medium range hydrological prediction capability for the U.S.

3) To develop the real-time drought monitoring capability for the U.S.

4) Test and implement improved data assimilation methods for both in situ and remotely sensed data

5) Various applications related goals, e.g., link to reservoir system models for reservoir contents analysis

Both Systems

Soil MoistureState

SnowpackState

Both Systems

VIC

Streamflow Routing NetworkBoth Systems

1/8 degree,Ohio R. basin

UW Forecast Approach Schematic

NCDC COOP station obs.

up to 3 months from

current

local scale (1/8 degree) weather inputs

soil moisturesnowpack

VIC Hydrologic model spin up

SNOTEL

Update

streamflow, soil moisture, snow water equivalent, runoff

25th Day, Month 01-2 years back

index stn. real-time

met. forcings for spin-up

gap

Hydrologic forecast simulation

Month 12

INITIAL STATE

ObservedSWE

Assimilation

ensemble forecasts ESP traces CPC-based outlook NCEP CFS ensemble NSIPP-1 ensemble

West-wide System

Seasonal Hydrological Prediction System

LSMVIC

NoahSAC

Routing

Multiple GCM Ensemble Forecast

NLDAS(initial conditions)

Bayesian Merging

Weather “Generator”(resampling and scaling historical time series)

1/8 degree

daily time step

1/8 degree

Monthly time step

Obs. ClimatologyClimate indices Teleconnection

1/8 degree

GCM resolution and Coarser

Large scale

Bayesian Merging

ESPVIC

NoahSAC

East-wide System

West-wide System

www.hydro.washington.edu/forecast/westwide/

http://hydrology.princeton.edu/forecast

East-wide System

SWE Soil MoistureRunoffPrecip Temp

Apr-06

May-06

Jun-06

Both Systems Spatial Forecasts of Variable Fields

1) Science Questions and Objectives

2) Background on both forecasting systems

3) Operational applications research areas- seasonal forecasting

-- climate forecasts-- initial conditions estimates

- shorter lead forecasting (15 day)- drought monitoring

4) External Interactions

Topics

Ensemble Streamflow Prediction (ESP)

ICsSpin-up Forecast

observed

recentmet data to generate

“perfect” ICs

ensemble of historical met datato generate ensemble

forecast

hydrologicstate

Applications: climate forecast

CPC Seasonal Outlook UseChallenge: Seasonal (3-month) probabilities must be converted to

daily meteorological values at the scale of the hydrology model

-5

5

15

25

35

Mon1

Mon2

Mon3

Mon4

Mon5

Mon6

deg

C

Applications: climate forecast

Flow location maps give access to monthly hydrograph plots, and also to raw forecast data.

Streamflow Forecast Details

Clicking the stream flow forecast map also accesses current basin-averaged conditions

Applications: streamflow

Bayesian Merging of Information

Bayes Theorem

)(

)|()(

)(

),()|(

yp

ypp

yp

ypyp

Likelihood function(relates local scale to GCM scale and

above)

Prior(local

climatology)

Posterior

1/8th degree scale variable

Variable at GCM scaleand above

Applications: climate forecast

Climatological Forecast

Streamflow: 198805 ForecastApplications: streamflow forecast

Realtime forecasts (Target month: 200511)

Target Month 200511

Lead 2 months

Soil is likely to be drier than normal

Target Month 200511

Lead 1 month

Soil will be drier than normal with more certainty

Applications: soil moisture forecast

Drought Monitoring (Forecast Validation)

Applications: soil moisture forecast

Realtime Drought MonitoringPrinceton, 1/8

degree

Long-termHistorical Observed

Atmos. Forcing

RealtimeAtmos. Forcing

VIC

Long-termHydrological States

VIC

RealtimeHydrological States

Drought-relatedAnalysis and Nowcast

NLDASRealtime

Atmos. Forcing

VIC

RealtimeHydrological States

UW, ½ degree

same

method

Applications: drought analysis / prediction

Real-time Daily NowcastSM, SWE

Applications: drought analysis / prediction

Realtime Drought MonitoringApplications: drought analysis / prediction

UW is implementing a 15-day global real-time hydrologic forecast

Initially using T. Hamill’s “reforecast” datasets to allow bias-correction

As procedures stabilize, 15-day forecasts will be incorporated into the US systems.

Applications: 15-day forecasts

Monthly Avg FlowMonthly Avg Flow

Bayesian Merging of Multi-LSM forecastsTesting in 3 basins (Salmon, Gunnison, Feather)- retrospective (simulation AND ensemble forecast modes)

Applications: Multi-model forecasts

1) Science Questions and Objectives

2) Background on both forecasting systems

3) Applications areas- seasonal forecasting

-- climate forecasts-- initial conditions estimates

- shorter lead forecasting (15 day)- drought monitoring

4) External Interactions

Topics

NOAA Applied ScienceUsers with Real Needs

West-wide Interactions

Sn

ow w

ater

con

ten

t on

Ap

ril

1

April to August runoff

McLean, D.A., 1948 Western Snow Conf.

SNOTEL Network

Hydrologic prediction and the NRCSPNW

West-wide Interactions

External Interactions

UW HydrologicForecast and Nowcast

Systems

U. Arizona / USBRforecast study, Lower

Colorado basin

NWS Hydrologic Ensemble Prediction

Experiment

3TIER Environmental Forecast Group

NRCS National Water and Climate

Center

NOAA Climate Prediction Center’s US Drought Outlook

Miscellaneous:Seattle City Light,energy traders,

hydropower utilities,NOAA regional climate offices

UW Rick Palmer Group Puget

Sound region flow forecasts

UW Climate Impacts Group (CIG)

Annual Water Outlook meetings

NOAA National Centers for

Environmental Prediction (NCEP) testbed activities

Columbia River Inter-tribal Fish

Commission

Klamath R. Basin Bureau of

Reclamation

UCI / California Dept of Water

Resources

WA State Dept of Ecology & Yakima R. Basin

Bureau of Reclamation

newUS Drought Monitor

Princeton University Hydrologic Forecast

System

West-wide Interactions

UW methods used in real-time CPC-based forecasts produced for a City of Seattle Water Utilities Consortium

Interactions

NCEP EMC(Ken Mitchell, Youlong Xia, and others)

West-wide and East-wide Interactions

RUNOFF

SWE

NOAHundersimulated snow

early runoff peak

Westwide System – Finish streamflow forecasting implementation for

Western half of US Implement reservoir contents forecasts Explore approaches for incorporating 15-day forecasts Refine snow-related data assimilation

Eastwide System - Finish streamflow forecasting implementation for Eastern

half of US Expand inputs to Bayesian merging of climate forecasts

Both - Continue testing and transfer of various elements to

NCEP EMC Resolve UW-Princeton method differences as two

forecasting domains are knit together

Future Plans

Thank you -- Questions?