This document discusses NOAA's river forecasting services and plans for improving hydrologic modeling. The 13 River Forecast Centers currently provide river level forecasts at 200 locations using precipitation and temperature forecasts. NOAA aims to develop street-level hydrologic modeling through the National Water Model, which will provide hourly streamflow simulations along 2.6 million river reaches at 1km resolution across the continental US. This high-resolution modeling will improve flood warnings and support emergency management.

1. Building a Weather-Ready Nation
Moving from Point Specific to Street Level Hydrologic Forecasting
David R. Vallee
Hydrologist-in-Charge
Northeast River Forecast Center
david.vallee@noaa.gov http://weather.gov/nerfc
A Look At Current & Future
Hydrologic Forecast Services;

2. 13 River Forecast Centers
Our Mission:
To provide our nation with river, flood and water resource
forecasts for the protection of life and property and the
enhancement of the national economy.

3. River Forecast Center Responsibilities
 Calibrate and implement variety
of hydrologic and hydraulic
models and produce temperature
and precipitation forecasts to
provide:
 River flow and stage forecasts at
200 locations
 Guidance on the rainfall needed
to produce Flash Flooding
 Ensemble streamflow predictions
 Ice Jam and Dam Break support
 Water Supply forecasts
 Reservoir Inflow Forecasts
Moderate flooding - Connecticut
River at Portland, CT.

4. Weather Forecast Office
New York/New England Service Areas
 WFO Caribou, ME
 Northeast Maine counties
 WFO Gray, ME
 Southwest Maine and New Hampshire
 WFO Burlington, VT
 Northern 2/3rds of VT
 WFO Albany, NY
 Srn 1/3 of VT, Berkshire, MA, Litchfield,
CT
 WFO Taunton, MA
 Rest of MA, all of RI, and the
northern 2/3rds of CT
 WFO Upton, NY
 All coastal CT Counties
 WFO Binghamton, NY
 Finger Lakes region
 WFO Buffalo, NY
 Buffalo Creeks, Genesee and Black

5. Weather Forecast Office
Responsibilities
 Watch/Warning responsibilities
 Coordinate final adjustments to RFC
forecasts for warning issuances
 Issue and coordinate all
watches/warnings with local interests
 Flood/Flash Flood
 Drought/Water Resource
 Hydrologic Outlooks
 Define forecast service requirements
 Establish flood stages and impact
statements for forecast points
 Work with RFC on developing
modeling requirements
 Provide Decision Support Services to
the Decision Makers in the region

6. River Flood Forecast Services for
Rhode Island
 Blackstone River
 Northbridge, MA
 Woonsocket, RI
 Pawtuxet River
 Scituate Reservoir
 Inflow and Downstream
discharge
 Cranston, RI (high flow only)
 Pawcatuck River
 Wood River Junction
 Westerly (Tidal)
 Wood River at Hope Valley

7. None of our services are possible without the
tremendous work of the U.S. Geological Survey
 Gaging Experts
 Maintaining the gage networks
 Streamflow, ground water
 Rapid Deployment gages
 Rivers and in tidal areas!
 Providing critical historical
archives
 Providing/Maintaining the
Ratings (stage vs. flow)
 Technical studies expertise
 Hydraulic modeling expertise
 Flood Inundation Mapping
http://waterdata.usgs.gov/ri/nwis/rt

8. Forecast Services
On A Watershed Scale
Requirements:
 Observed precipitation
 Observed temperatures
 Forecast temperatures and
precipitation
 Drainage area ≤ 100 sqmi
Our models help us forecast:
 The volume of water in the river &
that’s converted to stage/elevation
 Time of the peak elevation &
duration
 Soil moisture & Snow melt
 Unit hydrograph theory
 Reservoir Operations
 Hydraulics (HES-RAS) for complex
river systems
 Tidal reaches
 Lake Champlain, Farmington River

9. Precipitation Assimilation
Gage-only and Radar/Gage Multi-sensor Estimation
Hourly Multi-sensor Precipitation Estimation
(Radar / Gage Mosaic)
Hourly Multi-Sensor Grid Production
(1 hour grid analysis)

10. Community Hydrologic Prediction System
Snow water simulations
Streamflow simulations
Forecast snowmelt
Soil Moisture Modeling

11. The End Result
Our Graphical and Text Forecasts

12. NERFC Self-Briefing Page
http://www.weather.gov/nerfc - “Additional Info”

14. Meteorology Member-based Ensemble
River Forecast System (MMEF)
http://www.weather.gov/erh/mmefs
• Operational guidance system which
produces river forecasts based on 3
Numerical Model Ensemble Systems:
• Global Ensemble Forecast System
• North American Ensemble System
• Short Range Ensemble System
• Temperature and precipitation forcings
from each member of a given system
are run through the operational NERFC
river forecasting system
• Drives a suite of graphical guidance
showing spread & uncertainty
• Output includes;
• River flows
• Temperatures
• Precipitation
• Snowmelt

16. Ensemble Streamflow Prediction
 Weekly and 90 day probabilities of
exceedence
 Based only on historical time series
and historical meteorological forcing
 No real-time medium/long range
forcings at this time

17. Looking Toward The Future:
National Water Model & Improved Ensemble Prediction
GLOBAL
NATIONAL WATERSHED
STREET
Actionable Water
Intelligence
National Water Center

18. Hydrological Ensemble Forecast System
Set to replace the ESP approach later this year
Hydrologic Ensemble Forecasting System (HEFS)
• Forced by the mean Global Ensemble
Forecast System temps & precip 15 days
• Climate Forecast System forcings from
day 16-270
• Spread derived by parameters based on
past forecast system precipitation
performance (hindcasts)

19. Network River Flow
• A community-based hydrologic modeling framework
supported by NCAR
• Built upon the WRF-HYDRO Model Architecture
• Not dependent on a particular forcing data source or choice
of Land-Surface Model (LSM)
• Able to operate over multiple scales and with multiple physics
options
The National Water Model
Super-resolution Nets

20. WRF
Capabilities
20
Hourly
streamflow
simulation
9/12/13
Image:
accumulated
rainfall
Blue dots:
nodes along
stream
channels

21. WRF-Hydro Operational Configuration
Short-Range Long-Range
Analysis &
Assimilation
Hourly Hourly Daily (16 mem)
- 3 hrs
Cycling Frequency
0-18 hours 0-30 days
Forecast Duration
1km/250m/NHDPlus
Reach
1km/250m/NHDPlus
Reach
1 km/NHDPlus Reach
Spatial Discretization & Routing
MRMS blend/
HRRR/RAP bkgnd.
Downscaled
HRRR/RAP blend
Downscaled &
bias-corrected CFS
Meteorological Forcing
Medium-Range
Daily
0-10 days
1km/250m/NHDPlus
Reach
Downscaled GFS
Reservoirs (1615 water bodies parameterized with level pool scheme)
Assimilation of USGS Obs
21

22. • Hydrologic Output
– River channel discharge and
velocity at 2.6 million river reaches
– Surface water depth and subsurface
flow (250 m CONUS+ grid)
• Land Surface Output
– 1km CONUS+ grid
– Soil and snow pack states
– Energy and water fluxes
• Direct-output and value-added
geo-intelligence products
22
WRF-HYDRO IOC PRODUCTS
Current NWS river forecast points (red)
WRF-Hydro forecast points (blue)
22
Current NWS River Forecast Points (circles)
Overlaid with WRF-Hydro Stream Reaches
22
WRF-Hydro DOMAIN

23. 23
Hydrography, AHPS Forecast Points

24. 24
Hydrography, AHPS Forecast Points
1000 km
ABRFC
MBRFC
LMRFC
NCRFC
OHRFC

25. 25
NATIONAL INFRASTRUCTURE
Hospitals, EMS & Fire Stations
Full Resolution National Hydrography Dataset NHD+
AHPS Forecast Point
James River at Galena, MO
150 km
Springfield, MO

26. 26
NATIONAL INFRASTRUCTURE
Hospitals, EMS & Fire Stations
18 km
1 KM resolution
250 m resolution

27. NWS Water Prediction
Our focus over the next 3-5 years
TOMORROW
• Approximately 4500 forecast
locations at points
• Driven by large catchment
“lumped” modeling
• Requires:
– Precipitation and Air
Temperature (averaged over
watershed)
– Reservoir Information
– River Network Topology
– Hydraulic modeling for large
channels
– Stream Gage Data
– General Impacts near Gages
– Local servers and storage
TODAY
• Approximately 2,700,000
forecast stream reaches
• Driven by high/hyper resolution
Earth System modeling
• Requires:
– Full high-resolution
meteorological suite
– Reservoir Information
– Stream Network Topology
– Hydraulic modeling for small
channels
– High Resolution Terrain Data
– Land Cover Change Data
– Stream Gage Data (enhanced)
– Reach-based Inundation Mapping
and Impacts
– Centralized high-performance
computing
27

28. Building a Weather-Ready Nation
Moving from Point Specific to Street Level Hydrologic Forecasting
David R. Vallee
Hydrologist-in-Charge
Northeast River Forecast Center
david.vallee@noaa.gov http://weather.gov/nerfc
A Look At Current & Future
Hydrologic Forecast Services;