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 Management Average contribution to Lake Powell Apr-Jul inflow: Green River34% Colorado River50% San Juan River13% 2 Reclamation Midterm- Probabilistic Model Stakeholder Allocations Graphic from Dr. Katrina Grantz, Bureau of Reclamation In development… CFS-based flow forecasts for Reclamation water management 2

3 Example of Experimental Ensembles GFS and/or CFS based ensembles: CBRFC & CNRFC experimental products updated daily GFSCFS Contact: Andy Wood Flow into Lake Powell

Partners in Water Management Reclamation Colorado Basin Streamflow Forecasting Research Development Operations CBRFC Academic Researchers Gillies & Wang, USU Troch, UA Piechota, UNLV Moradkani, PSU Rajagopalan, CSU Wolter, CU Others: Becky Smith (student, CSU); Sponsors (CWCB) and Consultant (RTI) SI/Y2 Climate and Streamflow Forecasting Workshop NOAA/NWS Colorado Basin River Forecast Center Salt Lake City, UT – March 21-22, 2011 Organized bySponsored 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