Climate-Flow Forecast Research Motivations

ISI climate predictability is relatively limited in our region (CB)

water management in 7 states depends on regional climate and flow forecasts

plot -- JFM Precip correlation with Nino 3.4, lag 1 season

Linkage to Water/Energy ManagementLinkage to Water/Energy ManagementAverage contribution to Lake Powell Apr-Jul inflow:

Green River 34%Colorado River 50%San Juan River 13%

2

ReclamationMidterm-Probabilistic Model

StakeholderAllocations

Graphic from Dr. Katrina Grantz, Bureau of Reclamation

In development… CFS-based flow forecasts for Reclamation water management

2

3

Example of Experimental Ensembles Example of Experimental Ensembles

GFS and/or CFS based ensembles: CBRFC & CNRFC experimental products updated daily

GFS CFS

Contact: Andy Wood (Andy.Wood@noaa.gov)

Flow into Lake Powell

Partners in Water Management

ReclamationColorado Basin

Streamflow Forecasting Research

Development Operations

CBRFC

Academic Researchers

Gillies & Wang, USUTroch, UAPiechota, UNLVMoradkani, PSURajagopalan, CSU Wolter, CU

Others: Becky Smith (student, CSU); Sponsors (CWCB) and Consultant (RTI)

SI/Y2 Climate and Streamflow Forecasting WorkshopNOAA/NWS Colorado Basin River Forecast Center

Salt Lake City, UT – March 21-22, 2011

Organized by Sponsored by CBRFC Colorado Water Conservation Board Reclamation NIDIS

Testbed Data

Climate-Flow Forecast Needs NWS Hydrology strategy depends on REFORECASTS

a decade of experience showing that we must calibrate climate/wx forecasts to our hydrology model input characteristics

water management decisions affected by long persistence months to seasons: land surface storages (soil, snow) years: artificial reservoirs, groundwater ISI to multi-year sequences are critical to stakeholders historical analogs are informative – hindcasts serve this purpose too

What about downscaling/calibration, skill? hydrologists have been very active efforts by climate forecast producers will be appreciated, but…

skill assessments must be tailored to user scales, predictands of interest…probably cannot all be done by NCEP.

many users (such as RFCs) may downscale products themselves provide raw forecast-component data as well as semi-calibrated/MM-

combination.

When data become available, engage with informed users from different sectors to firm up products / services