Evaluation of the Performance of NiMet Daily Weather Forecasts in Jos, Plateau State

Public weather forecast accuracy is a cornerstone of meteorological service credibility and public trust in national weather agencies. This study evaluates the performance of NiMet daily temperature and rainfall forecasts for Jos, Plateau State, comparing 24-hour and 48-hour forecast products against observed weather data from the Jos Airport synoptic station over a two-year period (2022 to 2023). Categorical verification statistics, including probability of detection (POD), false alarm ratio (FAR), and critical success index (CSI), were computed for rainfall occurrence forecasts, while root mean square error (RMSE) and mean absolute error (MAE) were applied to temperature forecast evaluation. Results indicate that 24-hour rainfall forecasts for Jos achieve a POD of 0.72 and FAR of 0.35, with skill degrading notably at 48-hour lead times. Maximum temperature forecasts show a mean absolute error of 1.8 degrees Celsius, while minimum temperature errors are marginally higher at 2.1 degrees Celsius, attributed to challenges in capturing nocturnal boundary layer cooling over the Jos Plateau terrain. A user perception survey administered to 60 residents reveals moderate satisfaction with NiMet forecast services, with the most cited complaint being lack of specificity for intra-urban neighborhoods. The study recommends adoption of ensemble-based probabilistic forecasting methods and enhanced communication of forecast uncertainty to the public. Keywords: forecast verification, NiMet, Jos, rainfall prediction, temperature forecast.