Societal value of improved precipitation forecasts: A case study in surface transportation

Weather research offers the potential for improvements in weather forecasts, as measured by scientific criteria. Although the potential societal value from improved weather forecasts is substantial, the realization of that potential depends on a number of factors. Estimation of the actual (not just the potential) value of improved forecast technology requires a) a forecasting process that translates improved technology into improved forecasts, b) a communication process that effectively delivers forecast information to users in a timely fashion and in a form that can be used for making weather information sensitive decisions, c) users who incorporate the forecast product into their decisions in order to make better choices among available alternatives.

Estimation of the value of weather forecasts is a special case of the problem of valuing information. Decision theory provides an elegant method for making estimates of the value of information, but the validity of the resulting estimates has been shown to rest on some shaky assumptions. The shakiest of these is that users of the information are rational and act optimally on the information they are given. Descriptive methods are needed to incorporate realistic assumptions about decision making behavior into models for estimating forecast value.

We report a detailed case study of the impact of improved precipitation forecasts on ground transportation. Specifically, we examined the impact of improved precipitation forecasts on the snowfighting operations of the New York State Thruway. Currently available data and literature on forecast process, communication, and use were used in conjunction with observations and interviews with key decision makers to derive a model that yields estimates of value under various assumptions about forecast quality. It was found that the primary benefit of improved forecasts would be in the reduced application of salt to the roadway. It was also found that the full benefit of improved forecasts would require some adjustments in the way information is used by decision makers. A major lesson learned from this research is the importance of forecast verification data for supporting studies of the value of weather information.