Long Range Ensemble Streamflow Prediction.ppt

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Long Range Ensemble Streamflow Prediction.ppt Powered By Docstoc
					Western Water Supply

   Kevin Werner, Andrew Murray, WR/SSD
       Jay Breidenbach, WFO Boise
   Cass Goodman, Steve Shumate, CBRFC
    Alan Takamoto, Scott Staggs, CNRFC
           Don Laurine, NWRFC
         Chad Kahler, WFO Tucson

 Western Water Supply
    History

 Project overview
    Westwide map
    Forecast evolution
    Verification
    Ensemble services

 Future enhancements
    Climate variability and change
    Short range ensembles services
   Western Water Supply Forecasts

 Forecasts for spring runoff
  amounts from snow melt
  dominated basins in western
 Routinely produced at 6 RFCs
  and coordinated with other
  agencies (NRCS and
  California DWR)
 NWS forecast program began
  in 1940s
 Primary forecast tools:
    Ensemble Streamflow
    Multivariate Linear
                                 Legacy Water Supply Forecast
                                 Product (Credit: NRCS / NOAA)
                  Project in a Nutshell
   Goals:
      A “one stop shop” for NWS water information at the seasonal timescale
      Consistent presentation of products between RFCs
      Harness collective innovation from multiple offices
   Users:
      Existing Water Supply forecast users
          Strong support from USBR and state water resources agencies for
      Groups with cross basin interests (e.g. media, power companies)
      NWS internal users
   Major Components:
      Map: Single map for all western WS forecasts from 6 RFCs
      Forecast evolution: Plotting capability to show evolution of current year
       forecast and observed river flow
      Verification: Forecast evaluation from past forecasts and forecast tools
      Ensemble services: Interaction capability with ensemble streamflow
        Project in a Nutshell (con’t)
 Milestones (past):
    April 2005: Working group formed, planning meeting held
    January 2006: Initial website launched
    September 2006: Included AB, WG, and MB RFCs in development
    January 2007: Common database developed
    March 2007: Launched outreach effort and included SHs
 Milestones (future):
    August 2007: Launch verification 1.0 capabilities
    September 2007: Move software to NWRFC web farm
    October 2007: Launch forecast evolution 2.0
    October 2007: Launch ensemble services 1.0
    January 2008: Integrate WGRFC data
    2008?: Integrate climate change capabilities
   www.cbrfc.noaa.gov/westernwater

   “One Stop Shop” for NWS water
    supply forecasts

   Flexible and consistent map
    presence across western USA

   Zoomable to basin scale

   Mouse over capability for forecast
                     Forecast Evolution
   Evolution of current year forecast
    and observed streamflow

   Options to include:
     Normal streamflow volume
     Forecast window
     Forecast accumulation
     Accumulated Observed, etc…

   Originally developed at NWRFC

   Version 2.0 contract development
    work proceeding
     Add ESP forecasts
     Add interactive features
                      Forecast Verification
 Goal: Provide users of all types with forecast verification information
       Easy to understand
       Meaningful
       Accessible from forecasts
       Dynamically generated plots from database

                Data Visualization                         Error

                                      MAE, RMSE, etc

                                      Conditional on
                                     Lead time, year

                      Skill                             Categorical

 Skill relative to                  Traditional (NWS) verification including FAR
Climatology                          and POD

 Conditional                         Category definitions tied to climatology
                                     values (e.g. mean flow, terciles, etc.) or user

                                                              Plot credit: Chad Kahler
            Ensemble Services

 Goals:
   Intuitive user interface for current ensemble forecast

   Access to archived streamflow data for perspective

   Dynamic, flexible plots

   Access to underlying data and database

   Climate change scenarios
                    Climate Change

 Latest IPCC report confirms
  “temperatures averaged over
  all habitable continents … will
  very likely rise at greater than
  the global average rate in the
  next 50 years and by an
  amount substantially in excess
  of natural variability.” (IPCC
  WR1, 2007)

                                     Source: IPCC, 2007
Trends in 1 Apr SWE over the 1960–2002 (left) and 1950-1997
(right) periods of record directly from snow course observations
from Mote (2006) and Mote et al. (2005) respectively.
Extend NWS Product Suite?

                                          Climate Change
                                          based run off

 Current product suite covers hours to seasons;

 Should we consider climate change scenarios and build
  multi-year products for run-off, temperature, precipitation?

 User requirements from power companies, USBR, etc for
  climate change scenarios
                Water Supply with
                 Climate Change
 Many in water community are asking for it

 Idea: Provide scenario based water supply outlooks in the context of
  historical data and current season forecasts
     Include uncertainty

     Temperature, precipitation, and/or lead time based scenarios

     Ultimately link scenarios to atmospheric carbon based scenarios

     Leverage historical simulation capabilities in ESP
Leveraging ESP for long range scenarios

 Multiple “historical simulation” runs:
     Use historical basin temperature and precipitation time series

     Build ensemble by repeatedly shifting year order by one

     Incorporate scenarios through additive (temperature) or
      multiplicative (precipitation) year-wise adjustments
          Forecast Point: Columbia River at the Dalles Dam

Archive                Current Forecast        Climate Change             Options
O Normal Runoff        O Ensemble Streamflow   O Year (slider bar 2010-   O Accumulate over
                       Prediction O Ensemble   2050)                      period
O Model Normal         members by forcing
                       year(s)                 O Temperature (slider      O Plot Type (box and
O Historical Year(s)                           bar -5 F - +5 F)           whisker, bar, lines, etc.)
                       O Ensemble members
                       by ENSO                 O Carbon Scenario          O Data

                                                                          O Plot interval (set axes

 Western Water Supply
    History

    Current capabilities

 Coming enhancements
    Verification

    Water Supply ensemble services

 Climate Change
 Thank You


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