Case Study: Trends and Early Prediction of Rainfall in Jordan

Abstract

Fourteen meteorological stations distributed over Jordan were selected. Data of annual and monthly rainfall amount of autumn (October and November) for a period more than 50 years were analyzed to show their relationships with the normal annual rainfall. An attempt was made to use the standard deviation values in order to have an early prediction for the annual rainfall (less or more than the normal) depending on the autumn rainfall amounts. It is found that the annual rainfall exceeded the normal when autumn rainfall amounts were more than 30 mm in Jurf El Daraweesh, Qatraneh, Safawi, and Wadi Musa, 50 mm in Mafraq, 60 mm in Amman, and 100 mm in Salt and Irbed. Regression analysis projected weak increasing trends in autumn and decreasing trends in the annual rainfall in the majority of Jordan.