"The NWS National Precipitation Verification Program": Brett McDonald, COMET Postdoctoral Fellow (Camp Springs)

Final Report

The National Weather Service (NWS) and other hydrometeorological organizations have recently identified precipitation estimates and forecasts as important items for emphasis and improvement. A critical aspect of improving precipitation forecasts is verification. Currently, a variety of organizations perform routine precipitation forecast verification only for those forecasts applicable to that organization's needs. Within the NWS, precipitation forecasts are issued globally/regionally/locally by numerical weather predication and stastical models, the Hydrometeorological Prediction Center, River Forecast Centers, and Weather Forecast Offices. This progam has been created to perform verification for all steps in the end-to-end precipitation forecast process.

Tasks specific to this project included:

• Write, test, and evaluate the software code for a national quantitative precipitation forecasting (QPF) and probabilistic QPF (PQPF) verification program within the NWS.
• Write, test, and evaluate the software code for local QPF/PQPF verification at local NWS Weather Forecast Offices (WFOs), River Forecast Centers (RFCs), and the Hydrometeorological Prediction Center (HPC) of the National Centers for Environmental Prediction (NCEP).
• Develop, test, and evaluate methods for displaying and interpreting verification statistics via the Internet.
• Central to the precipitation forecast verification program is the utilization of precipitation estimates as the basis for the verification. Thus, emphasis will also be required within the program to obtain available/appropriate/accurate precipitation estimates.

More information about work conducted during and after the fellowship period is available from the paper:

Charba, Jerome P., Reynolds, David W., McDonald, Brett E., Carter, Gary M. 2003: Comparative Verification of Recent Quantitative Precipitation Forecasts in the National Weather Service: A Simple Approach for Scoring Forecast Accuracy. Weather and Forecasting : Vol. 18, No. 2, pp. 161–183.