| description abstract | Late evening weather forecasts by telecasters at major network television stations in seven United States cities, and corresponding forecasts from the National Weather Service, were monitored by meteorology students for 6 months in 1985?86. These forecasts were of temperature and precipitation for the three periods of ?tonight,? ?tomorrow,? and ?tomorrow night.? The accuracy of temperature forecasts was evaluated with three indexes: mean absolute error, root mean square error, and percentage of errors over 10°F. For precipitation, the indexes were Brier score (accuracy) and reliability. The accuracy of temperature forecasts was not greatly different for the telecasters and the NWS. Three of 20 pairings show a statistically significant difference according to the sign test; this is not much more than would be expected by chance. For precipitation similar results were obtained: only 1 of 20 Brier score pairings is statistically significant. The NWS has higher reliability scores, although no test exists for determining the statistical significance of this difference. | |
