CNRFC Operational Flood Forecasting

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CNRFCOperational Flood Forecasting

• Pete Fickenscher
• Hydrologist
• California-Nevada River Forecast Center
• National Weather Service
• October 18, 2006

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CNRFC Operations

• 11 Weather offices
• 220 Basins modeled
• 87 Flood Forecast Points
• Partners Calif. DWR
• Season Oct. 15 Apr. 15
• 50 Reservoir Inflow Points
• Partners COE BUREC
• Season year-round
• 50 Water Supply Points
• Season Jan.1 Jul. 1

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CNRFC Staff

• Hydrologist in Charge (HIC)
• Development and Operations Hydrologist (DOH)
• 4 Senior Hydrologists
• 3 Hydrologists
• 1 Senior HAS Forecasters
• 2 HAS Forecasters
• Administrative Assistant

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CNRFC Hydrologic Products
Short Range Long Range
Flash Flood Guidance Flood Forecast
Guidance
Reservoir Inflow Forecasts
Spring Snow Melt Forecasts

Water Supply Volume
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Flood Forecasting Operations
QPF
River Forecasts
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Operational Hydrologic Models

• NWSRFS Structure

Operational Forecast System
Calibration System
ESP
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Primary NWSRFS Models

• Rain-Snow Elevation
• Snow-17
• Sacramento Soil Moisture Accounting (SAC-SMA)
• Unit Hydrograph
• Reservoir Models
• River Routing Models

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NWSRFS Models

• Rain-Snow Elevation

Snowfall
Rainfall
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NWSRFS Models

• SNOW-17

• Conceptual Model of Physical Processes
• Models a Column of Snow
• - Accumulation of Snow Cover
• - Surface Energy Exchange
• - Snow Cover Ripening
• - Ground Heat Exchange
• - Transmission of Liquid Water
• Input Air Temperature Precip.
• Output Rain Melt, SWE, Areal Extent of Snow

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NWSRFS Models

• SNOW-17

WY 1986 SJ River
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NWSRFS Models

• SAC-SMA

• Conceptual Model of the Land Phase of the
  Hydrologic Cycle
• Input Rain Melt, Evapotranspiration, Areal
  Snow Cover
• Output Inflow to the channel system

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SAC-SMA
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NWSRFS Models

• SAC-SMA

WY 1986 SJ River
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NWSRFS Models
Actual Inflow (FOLC1) Observed (w) hourly
data Simulated (p) 6-hourly (with reservoir
outflows)
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NWSRFS Models

• River Routing Example

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NWSRFS Models

• Reservoir Model Example (Yolo Bypass)

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NWSRFS Models

• Tidal Example (Rio Vista)

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Operational Hydrologic Models

• NWSRFS Structure

Operational Forecast System
Calibration System
ESP
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Operational Flood Forecasting
Hydrologist
hydrologic expertise
H A S
QPF
River Forecast System
Rain/Snow Elevations
Forecast Temp
Soil, snow routing parameters
precip/temp/flow
Data Systems
Model Calibration
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Operational Flood Forecasting
Data Systems
Model Calibration
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Precipitation Data Quality Control
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Precipitation Data Quality Control
Gage Catch Issues

• Wind
• Snow
• Instrumentation (double tipping)
• Gage location (vegetation, topography)
• Vandalism

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River and Reservoir Data QC
Automated Filtering Manual QC
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Real-time Forecasting
NF American River
Observed Data
Simulated Flow
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Real-time Forecasting
Folsom Inflow
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Real-time Forecasting
San Joaquin River at Newman
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Operational Flood Forecasting
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Operational Flood Forecasting
Data Systems
Model Calibration
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Interactive Forecast Program
River Model
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IFP Runtime Modifications
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Operational Flood Forecasting
Hydrologist
hydrologic expertise
Graphical RVF
H A S
QPF
River Forecast System
Rain/Snow Elevations
Forecast Temp
Soil, snow routing parameters
precip/temp/flow
Data Systems
Model Calibration
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Graphical River Forecast Guidance
Merced River - Pohono Bridge
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Graphical RVF Availability

• 87 official flood forecast points.
• Routine updates.
• twice per day.
• morning/afternoon.
• Updates during floods.
• 8am/2pm/8pm/2am.
• as needed.
• Visible to everyone.

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Graphical River Forecast Guidance
Benefits

• Visual image of meteorological and hydrological
  situation.
• More information is presented than in a text
  product.
• Longer range guidance for emergency managers.

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ForecastingBalancing Timeliness and Accuracy
Forecast Lead Time
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Graphical River Forecast Guidance

• Guidance period information has higher
  uncertainty.
• Timing and amount of rainfall forecast.
• Rain/snow level forecast.
• Unanticipated reservoir regulation will affect
  downstream forecasts and guidance.

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New Website
http//www.cnrfc.noaa.gov/
Graphical RVF
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New Website
http//www.cnrfc.noaa.gov/
Other River Guidance
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Review of 2006 Flood Event
Folsom Inflow Forecasts
Graphs
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Operational Hydrologic Models

• NWSRFS Structure

Operational Forecast System
Calibration System
ESP
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ESP Products

• Reservoir inflows
• Unregulated rivers
• Extended forecasts

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AHPS Relevant Products
ESP Custom Product Generation

• CNRFC implemented AHPS locations
• Started in WY2005 on 70 points

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ESP Traces
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AHPS Relevant Products
ESP Custom Product Generation
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CNRFC Development Areas

• Flood Forecasting
• Dam Break Support
• Flash Flood Support
• Water Supply Forecasting
• Hourly Hydrologic Modeling
• Website
• http//www.cnrfc.noaa.gov/

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California-NevadaRiver Forecast Center
Thank You