Cyclone alert issued in the Arabian Sea

The low-pressure area in east-central Arabian Sea may have already intensified into a depression, according to US Navy updates.

It has also changed direction of movement to the northwest (was northeast to begin with), 600 km southwest of Mumbai.

It will intensify as a tropical cyclone and head for Oman, but will weaken ahead of making a landfall, the US Joint Typhoon Warning Centre said.

It will also take away entire monsoon flows with it; rains over India will be hit in the process though some forecasts suggest the west coast will continue to witness spells of rain.

The rain over mainland India can revive only after June 14, according to forecasts.

The US Centre has currently given the Arabian Sea system a ‘numbered cyclone’ (equivalent of a monsoon depression) status by giving it the tag ‘02A.’

Numbered cyclone status is penultimate step to naming a cyclone (in the instant case, it will be called Nanauk, a name suggested by Myanmar as per the naming protocol).

Earlier in the morning, the Centre had issued a cyclone formation alert bang in the middle of the Arabian Sea and a safe distance away from India’s west coast.

India Met Department had already picked up a causative low-pressure area in the region and put it under watch for intensification as a monsoon depression.

The US agency said that the brewing system has everything going for it for progressive development as a tropical cyclone.

The sea is warm to very warm in the area (31- to 32 degree Celsius), well beyond the threshold required for formation of a cyclone and its sustenance over the waters.

Secondly, the vertical wind shear (sudden change in wind direction and speed with height) is low between nine- to 18 km/hr, but has now increased to moderate levels of 27- to 37 km/hr.

Vertical wind shear in the heights can affect the storm structure that rises to 10- to 12 km in height. Higher values can lead to a collapse of the storm tower, weakening it.

The third factor supporting the intensification of the system is the good ventilation effect on the top, which allows the storm to breathe and sustain itself.