Colorado Basin River Forecast Centerand

Drought Related Forecasts

Kevin Werner

CBRFC drought related development projects:

1.Upper Colorado – Colorado above Kremmling (KRMC2) is a test basin for NIDIS. Discussion on:

- Existing forecast services- Snow / Precipitation- Water Supply

2. Arizona – Testing distributed model. Focus on improving existing forecasts, enhancing flash flood program, and producing soil moisture grids.

Outline

CBRFC Upper Colorado

Flood Forecasts / Routine Forecasts• Nominally provided at

~400 points every 6 hours out to 10 days.

• Flexible web interface to forecasts and data

• Requires large amounts of data (e.g. snow, precip, streamflow)

Hydrograph forecasts

Snow

Precipitation Analysis

• Rigorous process to produce high quality estimates of precipitation

• Grids, basin average, points• Hourly, 6 hourly, daily, monthly

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•NWS forecast program began in 1940s•Primary forecast tools:– Ensemble Streamflow

Prediction (described earlier)– Multivariate Linear

Regression

Forecast Evolution

Time evolution of forecast and observed streamflow

Plot options include:

-Observed monthly or seasonal streamflow

-Historical monthly or seasonal streamflow

-Forecast seasonal streamflow

-Accumulation options

Climate – Streamflow Relationship

Scatterplot and statistics describe relationship between streamflow and climate variability

Multiple Indices available (e.g. Nino3.4, MEI, PDO, etc)

Plots customizable

Statistics describing relationship (e.g. correlation, sample size, best fit line)

Ensemble ForecastsRFC Ensemble Forecasts

-Initially offered at NWS water supply points

-Display probability function for monthly volumes

-Tools included to query historical data and forecast ensemble members

-User customizable plots

Forecast Verification•Easy to understand• Meaningful• Accessible from forecasts• Dynamically generated plots from database

Data Visualization• Variety

Figure TS.5 (IPCC AR4, WG2). Illustrative map of future climate change impacts on freshwater which are a threat to the sustainable development of the affected regions.

Climate Change:Fresh Water Projections

“With a changing climate, water resources and how we manage them is going to become one of the most important issues we face in the coming years. It threatens to pit state against state and community against community so it is important that we take the issue very seriously at this early stage.”

-VADM Lautenbacher, 8/1/08

Climate Change Scenarios

16

Data Access•Access to forecast and observed data from database

Link with Water Resources Outlook• Link to OHRFC

developed water resources outlook

• Predictor for USGS water watch

Arizona distributed modeling

• CBRFC generating soil moisture grids for Verde and Santa Cruz River basins.

• Data assimilation could improve model states to address inconsistencies in time and space.

CBRFC and NIDISCBRFC ForecastsClimate and

Weather Forecasts

Hydro Models

Research

Decision Makers

Value

NIDISNIDIS

NIDIS