Weather Variation and Accuracy of Weather Prediction during Dry Season 2021 in the Jabotabek Using Voluntary Weather Observation Based on Social Media

Abstract

The dynamics of rain events in Indonesia are very high, which causes variations in the accuracy of predictions and in situ rainfall observations or remote sensing rainfall estimates. Observations of the several extreme weather events show that rain fall occurs unevenly, especially in the city areas of Jakarta, Bogor, Tangerang, and Bekasi, commonly abbreviated as the Jabotabek. This region is a vulnerable area to hydro-meteorological disasters and evaluate how the influence of rain variations on the accuracy of weather prediction is constrained by the scarcity of in situ precipitation data. Then, the purpose of this study was to promote voluntary weather observations and to get an overview of the variation in the incidence of rain in the Jabotabek area through the STMKG Weather Care program. This team designed form of observation as easy as possible for respondents to understand, simple, and not time-consuming and spreaded using Google Forms and disseminate via WhatsApp as the most popular social media today. The results of the form filling indicate that social media has the opportunity to be developed to support the collection of weather data. Based on the evaluation of the form filling, it shows that the form is sufficient so that the respondents make relatively few mistakes. Moreover, the respondent's error is generally in filling out the district's name. The results of this voluntary weather observation can be used for the analysis of weather variations and the evaluation of weather predictions. The results of the analysis show that the higher the variation in weather conditions, the higher the difficulty of prediction, as the Bogor area has an accuracy of only 25%. Meanwhile, places, where the weather tends to be homogeneous, have an effect with high accuracies, such as in Bekasi Regency, which reaches 85%.