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?