Christopher J. Martinez, Ph.D
Use of Retrospective Weather and Climate Forecasts to Improve Hydrologic Forecasts

Recently, the NOAA Earth System Research Laboratory/Physical Sciences Division (ESRL/PSD) produced an archive of retrospective forecasts (reforecasts) using a fixed version of the National Centers for Environmental Prediction’s Global Forecast System (GFS). The reforecasts are available for the period 1979 to the present ( Extensive sets of reforecasts are not commonly produced using the most up-to-date forecast models due to excessive computing costs. The use of a fixed model allows for the
estimation (and correction) of model biases and errors using a suitably long archive of forecasts.

Christopher J. Martinez, Ph.D
279 Frazier Rogers Hall
PO Box 110570, University of Florida
Gainesville, FL 32611
Phone: (352) 392-1864 x279
Fax: (352) 392-4092

The objectve of this work is to evaluate the use of reforecasts to improve short-term hydrologic forecasts by Tampa Bay Water. Tampa Bay Water uses a suite of custom models to forecast streamflow, groundwater levels, and demand at multiple scales. Specifically, this project will:
• Evaluate analog techniques to generate an ensemble of 1-14 day forecasts.

• Evaluate model output statistics (MOS) to produce bias-corrected forecasts.

• Assess the improvement in short-term forecasts of urban water demand and streamflow using reforecast archives.