Verification of The Weather Channel Probability of Precipitation Forecasts

Abstract

The Weather Channel (TWC) is a leading provider of weather information to the general public. In this paper the reliability of their probability of precipitation (PoP) forecasts over a 14-month period at 42 locations across the United States is verified. It is found that PoPs between 0.4 and 0.9 are well calibrated for near-term forecasts. However, overall TWC PoPs are biased toward precipitation, significantly so during the warm season (April?September). PoPs lower than 0.3 and above 0.9 are not well calibrated, a fact that can be explained by TWC?s forecasting procedure. In addition, PoPs beyond a 6-day lead time are miscalibrated and artificially avoid 0.5. These findings should help the general public to better understand TWC?s PoP forecasts and provide important feedback to the TWC so that they may improve future performance.