Robert Shedd Northeast River Forecast Center National Weather Service Taunton, Massachusetts, USA

Robert Shedd Northeast River Forecast Center National Weather Service Taunton, Massachusetts, USA

Outline River Forecast Centers FEWS Implementation Status Forcing Data Ensemble Forecasting

The Northeast River Forecast Center

River Forecast Centers Mission: Protection of Life and Property Flood Guidance Water Supply 13 River Forecast Centers across USA 120 Weather Forecast Offices

Nearly 200 forecast location Time to Peak: 6-48 hours Elevation from 0 6600 ft River Basins Connecticut Hudson Merrimack Kennebec St John Staff of 14 Located in Taunton, Massachusetts Northeast RFC

River Forecast Center Responsibilities Calibrate and implement a variety of hydrologic and hydraulic models to provide: River flow and stage forecasts at 180 locations Guidance on the rainfall needed to produce Flash Flooding Ensemble streamflow predictions Ice Jam and Dam Break support Water Supply forecasts Partner with NOAA Line Offices to address issues relating to Hazard Resiliency, Water Resource Services, Ecosystem Health and Management, and Climate Change

CHPS : Community Hydrologic Prediction System

CHPS Implementation Forecast Configuration converted for CHPS New data feeds established and being validated Beginning 6-12 months of parallel operations

CHPS: C = Community FEWS Models CHPS??? Models FEWS FC NWS Models HEC Models National Weather Service Northeast River Forecast Center 9

Community: Hudson River River is tidal to Albany 150 river miles Current FLDWAV model does not account for wind Stevens Inst of Technology running 3D model of Hudson

Community: St John River St John River flows from Maine (USA) into New Brunswick (Canada) Several common forecast points International boundary for about 110 km Major Flooding April 2008 Need for better data exchange

Model States Displays

Snow Model Displays

Forecast Modifiers

Forcing Data

Forcing Data for CHPS NWSRFS relies on point observations of precipitation and temperature Decision to move to gridded forcing data and not port legacy data preprocessors

Radar Based Preciptation Hourly analysis Merges radar and gage information 4 km grid

Gage Based Precipitation Daily and 6-hour analysis About 600 daily observations 1 gage / 450 km 2 Uses only gage observations Extensive manual quality control of gage data

Precipitation Forecasts 6 hourly analysis Forecaster choice of data source and amount of manual adjustment Up to 48 hours of forecast data in model

Observed Temperatures Currently using RUC13 initialization Hourly data averaged to 6-hour mean

Forecast Temperatures Can use variety of sources of forecast temperature Model guidance National guidance Forecast office guidance 6 hour average temperature

Forcings Assessment Comparison of different forcings relative to legacy system precipitation and temperature Retrospective analysis runs with each forcing type to demonstrate impacts of any differences on hydrologic models

ENSEMBLE FORECASTING

Long Term Ensembles Based on long term record of basin average precip and temperature 30-day outlooks Other regions: 90+ days Limited use due to local climatology

Short Term Ensembles 1-10 probabilistic outlook Based off meteorological models Short Range Ensemble Forecast (SREF) Global Ensemble Forecast System (GEFS) Significant bias issues

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