SASCOF confirms IMD’s forecast of near-normal monsoon for 2017
New Delhi: The South Asian Climate Outlook Forum (SASCOF) has confirmed the India Meteorological Department’s (IMD) prediction about the most likely normal rainfall during the 2017 southwest monsoon season over much of the South Asia.
According to the outlook, normal rainfall is expected over the Southern parts of Asia, while above normal will occur over the broad areas of eastern and south western parts of the region. Below normal is expected over the areas of north-western, central and south eastern parts of South Asia.
The South Asian Climate Forum was developed through an expert assessment of various observed and emerging climatic features that influence the monsoon, including the El Niño-Southern Oscillation (ENSO). Many other regional factors, including the Indian Ocean Dipole (IOD) conditions over the Indian Ocean, as well as winter and spring snow cover over the Northern hemisphere were also considered.
The Forum was held in Bhutan from 24-26 April.
The weak La Nina conditions that prevailed over the Pacific during the latter part of 2016 weakened and turned to neutral ENSO conditions in January 2017. Currently, warm neutral ENSO conditions are prevailing.
Forum said , “there is strong consensus among experts that neutral ENSO conditions are likely to continue through the spring season and weak El Nino conditions are likely to develop in the second half of this year.”
It also said that there is uncertainty about the development and timing of El Nino conditions. Apart from this,there is also uncertainty about the impact of development of weak El Niño conditions on the southwest monsoon season rainfall over the region.
Earlier this month, IMD forecast a near-normal monsoon for 2017 based on the low probability of El Niño. According to IMD, there was close to 50% probability of El Niño prevailing for the period of July-September, which was reduced to around 40% at the beginning of April.
But according to a US based International Research institute for Climate and Society, the probability of El Nino occurring during peak of the monsoon season has increased. According to their early April forecast, the probability of the onset of El Niño during the monsoon months of June-September was below 50%, but things have changed in the last two weeks. According to the new forecast, there is over 55% likelihood of El Niño appearing during the months of May-July and close to 70% chance during July-September()
The Southwest monsoon rainfall accounts for 70-80% of annual rainfall in most countries of South Asia. It’s a driving force for the socio –economic development in the world’s most densely-populated region.
For preparing the consensus forecasts, the forecast climate model products from various Meteorological Organization centers such as IMD, Indian Institute of Tropical Meteorology, National Centre of Environment Prediction-National Oceanic Atmospheric Administration, Bureau of Meteorology, Australia, China Meteorological Administration (CMA), WMO’s Lead Centre for Long Range Forecasting - Multi-Model Ensemble, Japan Agency for Marine-Earth Science and Technology, etc were considered.