THE INFLUENCE OF LA-NINA PHENOMENA ON PAKISTAN’S PRECIPITATION

Pakistan has a long latitudinal extent, and the rainfall variability during different seasons is considerably high. Pakistan experience bi-model rainfall behavior termed as Monsoon rains and winter rains. Winter rains are normally confined to above 30° Latitude. In some years, winter rains fail and pose serious threat to hydro-meteorological resources and agriculture. Such conditions are seen to have close relation with fluctuations in Sea Surface Temperatures in Pacific Ocean. The country recently remained under the grip of a severe drought during the period 1998 to 2001 which disrupted the economy badly besides human and live stock killings. This was the period of cold episode in Pacific Ocean termed as La Nina phenomena and it was believed that history’s worst drought conditions over South Asia were triggered by La Nina phenomena. In this study, effort has been made to investigate the behavior of winter rainfall over Pakistan in relation to La Nina phenomena and provide a qualitative tool for predicting winter rains on the basis of SST forecast over the Pacific