The journey for Monsoon 2019 have finally begun, though on a delayed and weak note. Ever since the beginning of pre-Monsoon season, situation has been grim. Rainfall has been missing from the country, with Northeast India coming as savior. Pre-Monsoon season of 2019 ended with deficiency of 25%, driest in the last 65 years.
Looking at this, weathermen had predicted delayed onset. In fact, as we moved closer to June, situation even became more worse. However, then came a cyclonic circulation in Southeast Arabian Sea around June 4, that aligned all the required features for the onset of Monsoon that included rainfall, wind speed and direction and Outgoing Longwave Radiation (OLR). It was nothing less than a miracle for India, which is staring at a below normal Monsoon season for the second consecutive year.
As reiterated by Skymet Weather, there are mainly three reasons for the onset of Monsoon. Usually it is a strong system in Bay of Bengal that drives the Monsoon surge. If not this, then may be a vortex in Arabian Sea which then comes into play.
Above these two is the Monsoon surge. If the Monsoon surge is strong, it can overpower every system and makes an onset. However, this was not the case this time. As per the weathermen, Monsoon wind pattern is not favourable for the formation of any strong weather system. Thus, it is seen that the formation of any cyclonic storm during the Monsoon season is very rare.
Nonetheless, the above-mentioned weather system, which is now seen as a low-pressure area was responsible for the onset of Monsoon 2019 on June 8. But what was a boon for India, would now be the reason behind the slow advancement of Monsoon surge.
The low-pressure area has been travelling in favourable weather conditions of extremely warm sea surface temperatures and low vertical wind shear. With this, it has been gaining strength continuously and we expect it to intensify into a depression in the next 48 hours. It has the full potential to become a cyclonic storm or even into an extremely severe cyclone.
However, as the system gets more powerful, rains would start reducing over the Indian mainland. Though West Coast would see some rains but rest parts would see significant drop in Monsoon rains.
The probable cyclone would then govern the wind pattern, where in it would tracking north-northwest, running parallel to the coast but maintaining sufficient distance. Thus, restricting the progress of Southwest Monsoon. What was once the boon, would eventually become bane.
Any information taken from here should be credited to skymetweather.com