IMD: Northeast monsoon ‘most likely to be normal’
The forecast comes as a breather to the people of Tamil Nadu and Kerala as several parts of the two states have been facing drought-like conditions after they received “deficient” rainfall last year, this year it seems the southern part of the country would receive normal rainfall
The forecast outlook released on Tuesday for the northeast monsoon over the south peninsula predicted that the region, including Tamil Nadu, coastal Andhra Pradesh, Rayalaseema, Kerala and south interior Karnataka, would receive between 89% and 111% of the long period average (LPA) rainfall for the region.
The northeast monsoon, brings a significant amount of rainfall to parts of India’s southern peninsula.
The southern peninsula consisting of five subdivisions of the IMD – Tamil Nadu, Coastal Andhra Pradesh, Rayalaseema, Kerala and south-interior Karnataka – receive about 30 percent of its annual rainfall during the northeast monsoon season
The season remains active from October to December.
Long period average (LPA)
A low-pressure area, low, or depression is a region on the topographic map where the atmospheric pressure is lower than that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. The formation process of a low-pressure area is known as cyclogenesis.
The latest Monsoon Mission Climate Forecast System indicates a high probability for cooling of the sea surface temperature over equatorial central and east-Pacific, leading to cool El-Nino neutral conditions during the 2017 northeast monsoon
El Niño is characterized by a large scale weakening of the trade winds and warming of the surface layers in the Equatorial eastern and central Pacific Ocean. El Niño events occur irregularly at intervals of 2-7 years, although the average has been, until recently, about once every 3-4 years and lasting 12-18 months.
El Niño Southern Oscillation refers to the cycle of warm and cold temperatures, as measured by sea surface temperature, SST, of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific.