The India Meteorological Department (IMD) has issued its first ever summer forecast which predicts a slightly higher temperature during April-June across the country in 2016 than what it was in 2015.
IMD Director DS Pai said the dynamic forecasting system will not just help in forecasting monsoon but also summer and winter temperatures.
What was the need ?
According to Rai, so far we have been concentrating more on the rainfall forecast — the north-east monsoon. Now our concentration is shifting to temperature along with rainfall. In recent years, we have been witnessing increasing temperature in addition to rainfall. We know that 2015 was the warmest globally and Indian temperatures were also the warmest in the record. So there was a requirement for this type of forecast. We have developed a dynamic forecasting system, which has some useful skill for forecasting not just rainfall but temperature also.
What is the IMD forecast this time year?
The annual temperature is going to be close to that of 2015. But as far as the summer is concerned, generally we see that with the declining impact pace of the El Nino, the temperature rises in north-west and central India. So, we expect a warm summer this year.
Generally, in summer you get maximum temperature in north-west and central India. However, the forecast says all sub-regions will have above normal temperature. However, in the core heat wave region of north-west and central India, the temperature will be around 1 degree above the average in the three months this summer.
The summer forecast extends from April to June.
Generally, in April heat waves will be more in the central part, in May it is in north-west and central India, and in June more of heat waves will be in north-west India. So April- June is generally known for the hot weather season. And forecast is for these three months.
As of now, the monsoon indicators are not so bad because El Nino is declining. However, the forecast from our climate model shows that even if the La Nina effect impact is felt, it will be take place only after the monsoon season. So during the monsoon season, El Nino conditions are most likely to be neutral.
It is not just El Nino that affects the monsoon as other factors like the temperature over Indian Ocean, land heating, snow cover and more factors have to be taken into account. So generally the picture becomes clearer in the middle of April and that is when we are expecting to give the first forecast for monsoon.
The IMD’s initiative comes even as India bears the brunt of one of the longest and severest El Ninos ever experienced. Said to be responsible for two consecutive droughts as well awry winter patterns in North India, the El Nino — a meteorological phenomenon marked by an unusual warming of the surface waters of the Pacific Ocean and associated with droughts — is likely to continue for a couple of months more.
The IMD does give warnings about imminent heatwaves and dry weather but these are no more than five days ahead. The key factor to forecasting weather a few months ahead is in ensuring that the computerised weather models are consistently able to simulate the weather as it actually plays out.