Transcript Western Water Supply

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 Tuscon
RFC Verification Workshop, 08/14/2007
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Outline
• Western Water Supply
– History
• Project overview
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Westwide map
Forecast evolution
Verification
Ensemble services
• Future enhancements
– Climate variability and change
– Short range ensembles services
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Western Water Supply Forecasts
•Forecasts for spring runoff amounts
from snow melt dominated basins in
western US
•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 Prediction
– Multivariate Linear Regression
Legacy Water Supply Forecast
Product (Credit: NRCS / NOAA)
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Project in a Nutshell
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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
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Users:
– Existing Water Supply forecast users
• Strong support from USBR and state water resources agencies for examples
– Groups with cross basin interests (e.g. media, power companies)
– NWS internal uses
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Major Components:
– Map: Single map for all western WS forecasts from 6 RFCs
– Forecast evolution: Plotting capbility to show evolution of current year forecast
and observed river flow
– Verification: Forecast evaluation from past forecasts and forecast tools
– Ensemble services: Interaction capapility with ensemble streamflow predication
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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):
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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
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Map
www.cbrfc.noaa.gov/westernwater
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“One Stop Shop” for NWS water
supply forecasts
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Flexible and consistent map
presence across western USA
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Zoomable to basin scale
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Mouse over capability for
forecast values
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Forecast Evolution
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Evolution of current year forecast
and observed streamflow
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Options to include:
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Normal streamflow volume
Forecast window
Forecast accumulation
Etc
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Originally developed at NWRFC
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Version 2.0 contract development
work proceeding
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Add ESP forecasts
Add interactive features
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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
• Skill relative to
Climatology
• Conditional
Categorical
•Traditional (NWS) verification including
FAR and POD
• Category definitions tied to climatology
values (e.g. mean flow, terciles, etc.) or
user definable
Plot credit: Chad Kahler
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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
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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
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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.
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Extend NWS Product Suite?
Years
Climate Change
based run off
scenarios?
• 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, BoR,
etc for climate change scenarios
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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
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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
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ENSEMBLE FORECAST SERVICES
Forecast Point: Columbia River at the Dalles Dam
Archive
Current Forecast
Climate Change
Options
O Normal Runoff
O Model Normal
O Historical Year(s)
O Ensemble
Streamflow Prediction
O Ensemble members
by forcing year(s)
O Ensemble members
by ENSO
O Year (slider bar
2010-2050)
O Temperature (slider
bar -5 F - +5 F)
O Carbon Scenario
O Accumulate over
period
O Plot Type (box and
whisker, bar, lines, etc.)
O Data
O Plot interval (set
axes limits)
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Summary
• Western Water Supply
– History
– Current capabilities
• Coming enhancements
– Verification
– Water Supply ensemble services
• Climate Change
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Thank you
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