roadmap for hydrologic ensemble forecast services
DESCRIPTION
Roadmap for Hydrologic Ensemble Forecast Services. Outline. Challenges Solution – Seamless suite of Hydrologic Ensemble Forecast Services (HEFS) Current vs. HEFS Key HEFS Components Status and Schedule Field Testing Budget Issues and Risks. Background: Water Forecasting Challenges. - PowerPoint PPT PresentationTRANSCRIPT
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Roadmap for Hydrologic Ensemble Forecast Services
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Outline
• Challenges• Solution – Seamless suite of Hydrologic Ensemble
Forecast Services (HEFS)– Current vs. HEFS– Key HEFS Components– Status and Schedule
• Field Testing– Budget
• Issues and Risks
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Background: Water Forecasting Challenges
• Implement mature hydrologic science into NWS operations within the constraints of existing infrastructure (data, IT, and people)
• Calibrate and enhance hydrologic modeling systems for multiple time scales and over diverse hydroclimatic regimes
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Problem
• Current short-range river forecasts are single-valued• RFC forecasters examine selected set of “what-if” scenarios• Other ensemble products include bias• No integration of short, medium, long range NWP forecasts
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Objective: Ensemble Based Probabilistic Forecast Products
• Run ensembles of inputs through river models to generate hydrologic forecasts
• Analyze ensemble information to quantify forecast uncertainty and produce a full range of possible hydrologic scenarios
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Hydrologic Ensemble Forecast Services (HEFS)
• End-to-end hydrologic ensemble forecast service currently under development
– Comprehensive plan developed in 2007 (the first of its kind in the world)
– Based and built on leading-edge science and technology
– OHD collaborating with NCEP, OAR and universities through:• The Observing-System Research and Predictability Experiment (THORPEX)
• Climate Prediction Program for the Americas (CPPA) Core Project
• The Hydrologic Ensemble Prediction Experiment (HEPEX)
• Research grants
• Field deployment via the Community Hydrologic Prediction System (CHPS)
• Experimental (prototype) components under evaluation at some RFCs
• Additional prototype deployments during the next 2 years
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Current (Seasonal ESP) vs. HEFS
Feature Current HEFS
Platform NWSRFS(inflexible, outdated)
CHPS (flexible, modern)
Forecast Horizon
Weeks to Seasons Hours to Years
NCEP Input None CPC, EMC, HPC
Bias Correction None NCEP InputsHydro Model Outputs
Hydro model uncertainty
Not addressed Addressed
Output format Limited number of simple graphics based on Ensemble Streamflow Prediction (ESP)
Web-enabled interactive toolbox
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Weather & Climate Forecasts
Assess Hydrologic Model Error
Correct NCEP Model Bias
Create Hydrologic Ensembles
Hydrologic Ensemble Prediction System:Key Components
AssimilateData
Correct Hydrologic Ensemble Bias
QPE, QTE, Soil Moisture
Streamflow
Verificatio
n S
ystem
Generate Product
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IFP
OFS
Raw flow ens.
Pp’ed flow ens.
Ensemble Verification
System
Flow Data
Product Generation Subsystem
Ensemble verification
products
Hydrologic Ensemble Hindcaster
Ens. User Interface
EPP User Interface
Ens. Pre-Processor
Atmospheric forcing data
Ensemble/prob.
products
Ens. Post-Proc.
Ens. Streamflow Prediction
System
HMOS Ensemble Processor
MODs
EPP3 ESP2 EnsPost EPG
EVS
Hydro-meteorol. ensembles
XEFS Graphical User Interface
Web Inter-face
XEFS linkage: XEFS linkage: EXperimental Ensemble Forecast System (XEFS)EXperimental Ensemble Forecast System (XEFS)
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Hist. RFC s.-v. fcst
Hist. obs
GFS ens. mean refcst
RFC stat. parameters
GFS stat. parameters
Real-time RFC fcst
Real-time GFS fcst
Strat. Cond. Simulation
Strat. Cond. simulation
Hist. ens.
Prob. M. & S. Shuffle
Prob. M. & S. Shuffle.
Joining / Blending
CFS ens. refcst
CPC outlook fcst
CFS stat. parameters
Real-time CFS fcst
Strat. Cond. simulation
Probability shifting
Prob. M. & S. Shuffle
Day 1-to-5 ens.
Day 1-to-14 ens.
Day 15~ ens
Ens. fcsts
Climate indices
Samp. from Hist. ens.
Day 15~ ens.
Merging of RFC & GFS Day 1-5 ens.
Merging Day 15~ fcsts
Generic ens.
Parameter estimation
Day 15~ ens.
Merged Day 1-5 ens.
Merged Day 15~ fcsts
Parameter estimation
Parameter estimation
Hist. ens.
Hist. obs
Hist. ens.
Short-Range
Medium-Range
Long-Range
Merging, Joining & Blending
Proposed HEFS Components Proposed HEFS Components
Other Ensembles
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Ensemble Pre-Processor
Hydrologic Model Output Statistics
(HMOS) Ensemble Processor
Ensemble Verification
Hydrologic Ensemble Hindcaster
HEFS – Field Testing
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Today
CHPS and HEFS Deployment Plans
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HEFSPrototype components development
Develop software-engineered AWIPS II baseline software
9 RFCs4 RFCs
HEFS capabilities first available to RFCs
2008 2009 2010 2011 2012FY
CHPS
Hydrology Program Funding
FY08 FY09 FY10 FY11
CHPS $1.2M $2.8M $2.5M $1.0M
HEFS $1.5M $1.2M $1.2M $1.2M
Funds two NCEP staff
and two collaborativeresearch grants
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HEFS Challenges
• Science– HEFS is a tool; research continues on how best to use that tool
• How to produce hydrologic ensemble forecasts based on meteorological ensembles
– Extreme events (e.g. record flooding) are harder to monitor and forecast:• Record conditions are outside model limits without historical analogs
– Products must be understandable / actionable– Forecast cone must be small enough for effective decision support
• Better accuracy required from both met and hydro models
• Implementation– Prototype software is not baseline software
• OHD staff to implement HEFS is focused on CHPS into 2011
• Delivery with CHPS will be prototype code integrated into FEWS
– RFCs will need to calibrate HEFS– We need to train forecasters– Web farms will need to handle more complex data requests– RFCs will require additional computer resources to operate in an ensemble mode
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Issues and Risks
Issue/Risk Mitigation Strategy Assistance
AWIPS II delays will result in further delay of AHPS research-to-operations (e.g., quantification of short-term uncertainty)
The Community Hydrologic Prediction System (CHPS) will be deployed with AWIPS II to support robust enhancements to the core river forecasting system
Maintain high priority focus on AWIPS II
CHPS delays will defer ensemble forecast system deployment
Maintain high priority focus on CHPS and short-range ensemble techniques
None