Wednesday - U.S. Drought Monitor Forum

1. Hydrologic Forecasting & Drought Assessment Tools From
the California Nevada River Forecast Center
US Drought Monitor Forum
April 14-16, 2015
Reno, NV
Alan Haynes
Service Coordination Hydrologist
NOAA/NWS – California Nevada River Forecast Center

2. Overview
• Characteristics of CNRFC hydrologic modeling &
type of information provided by the CNRFC
• Highlight some features of the CNRFC webpage
• Water resources
• Climate/Drought
• Observed precipitation
• Ensemble forecasts

3. CNRFC Operations
• 245,000 sq. miles
• ~270 Basins modeled
• 94 Forecast Points
• ~60 Reservoir Inflows

4. Hydrologic Modeling
Modeling Components
•Rain-Snow Elevation
•Snow-17
•Soil Model (SAC-SMA)
•Unit Hydrograph
• River Routing Models
• Reservoir Models
Model Characteristics
• Spatially Lumped Basins
• semi-lumped mountainous basins:
lower, middle & upper zones
• Six Hour Time-Step

5. Deterministic (single-trace)
Streamflow Prediction
Daily RFC
Forecasting
•Data Ingest
•Data QC
•Model Updating
Current States
•Soil
•Snow water
•Reservoir Levels
•Streamflow
Forecast
Meteorology
Mean Areal
Time Series
Precipitation
Temperature
Hydrologic
Models

6. Ensemble (multi-trace) Streamflow
Prediction
Daily RFC
Forecasting
•Data Ingest
•Data QC
•Model Updating
Current States
•Soil
•Snow water
•Reservoir Levels
•Streamflow
Forecast
Meteorology
Mean Areal
Time Series
Precipitation
Temperature
Hydrologic
Models
Historical
Time Series
MAPs/MATs
All Years of
Record

7. He
Ensemble River Forecasts
Timeline
ModelRunTime
Observed Weather
Streamflow
Model States
Short Term Weather
Models
Days 1-15
Climatology
Days 16-365
Streamflow Forecasts

8. Ensemble Forecasts
• Start with current model states
• Feed hydrology model with multiple meteorological possibilities
• Result is 60+ hydrographs

9. World Wide Web

36. Summary – Water Resources
• Water Resources Page
• WY observed flow to date
• Observed flow for previous year
• Seasonal and WY volume forecasts
• Date of peak flow

37. Summary – Drought & Precipitation
• Climate/Drought Page
• Drought Monitor
• Seasonal Outlooks
• Observed precipitation
• Recent precipitation
• WY to date precipitation

38. Summary – Ensemble Forecasts
• Ensemble Forecasts
• Raw ensembles – 10 Day Traces
• Apr-Jul & WY Volume Forecasts
• Trend Plots
• Sacramento Valley WRI

39. Planned Tools
Droughts reflect multi-year precipitation shortages,
so…
The CNRFC plans to produce water resources products
that look back over the past three years.