OBSERVATIONS IN AID OF WEATHER PREDICTION FOR NORTH-AMERICA - REPORT OF PROSPECTUS DEVELOPMENT TEAM 7

One of the most significant impediments to progress in forecasting wea ther over North America is the relative paucity of routine observation s over data-sparse regions adjacent to the United States. Prospectus D evelopment Team Seven was convened to consider ways to promote researc h that seeks to determine implementations of observing systems that ar e optimal for weather prediction in the United States. An ''optimal'' measurement system is considered to be one that maximizes the ratio of societal benefit to overall cost. The thrust of the conclusions is th at existing means of estimating the value of current observing systems and the potential benefits of new or proposed observing systems are u nderutilized. At the same time, no rational way exists for comparing t he cost of observations across the spectrum of federal agencies respon sible for measuring the atmosphere and ocean. The authors suggest that a rational procedure for configuring an observation system that is op timal for weather prediction would consist of the following steps. 1) Identify specific forecast problems arising from insufficient data. Ex amples might include hurricane landfall and intensity forecasts, 24-h forecasts of intense extratropical cyclones affecting the West Coast a nd Alaska, and medium-range forecasts of severe weather for all of Nor th America. 2) Use contemporary modeling techniques, such as observing system simulation experiments, ensemble forecasting, and model adjoin t-derived sensitivities, to delineate measurement requirements for eac h specific forecasting problem and identify candidate observing system s and data assimilation techniques that could be brought to bear on ea ch problem. 3) Estimate the incremental forecast improvements that cou ld plausibly result from the added or reconfigured data and the societ al benefits that would accrue from such improvements. 4) Estimate the overall cost (to the nation, not to specific federal agencies) of obta ining the data by the various candidate techniques and the benefits th at are projected to result. 5) Use standard cost-benefit analysis as a basis for deciding the optimal deployment of measuring systems. The a uthors believe that a rational approach to atmospheric measurement is critical to further improvements in weather prediction and that such i mprovements might very well be made within the current budget of routi ne observations, integrated across all of the responsible federal agen cies. This document outlines a proposed strategy for rationalizing atm osphere observations in aid of weather prediction in the United States . The paper begins with a summary of recommendations.