The accuracy of weather forecasts for Melbourne, Australia

Abstract

AbstractAn analysis of the accuracy, and trends in the accuracy, of medium‐range weather forecasts for Melbourne, Australia, is presented. The analysis shows that skill is evident in forecasts of temperature, rainfall, and qualitative descriptions of expected weather up to 7 days in advance. The analysis also demonstrates the existence of a long‐term trend in the accuracy of the forecasts. For example, Day‐3 forecasts of minimum temperature in recent years (average error ∼1.6 °C) are as skilful as Day‐1 forecasts of minimum temperature in the 1960s and 1970s, whilst Day‐4 forecasts of maximum temperature in recent years (average error ∼2.0 °C) are more skilful than Day‐1 forecasts of maximum temperature in the 1960s and 1970s. It is suggested that this trend may be largely attributed to: a combination of (1) enhancements in the description of the atmosphere's initial state provided by remote sensing and other observational technologies; (2) advances in broad‐scale numerical weather prediction (NWP); and (3) improvements in the forecast process that are supported by good organizational management, including developing and implementing new prediction techniques, and careful succession planning. Copyright © 2008 Royal Meteorological Society