Very severe cyclone ‘Vayu’ has maintained its power and intensity over the North Arabian Sea, off the Saurashtra coast in Gujarat (to the East) and the Karachi coast in Pakistan (to the West), into the second day on Friday.
The India Met Department (IMD) said the system has clearly skirted the Saurashtra coast for now and would continue to drift slowly to the West (towards Oman) over the next two days.
To take U-turn
Later, it is forecast to abruptly stop on its tracks, start weakening and take a sharp U-turn towards the Rann of Kutch and North Gujarat.
This, according to the US Joint Typhoon Warning Centre, would happen under the influence of a western disturbance moving towards North-West India across Afghanistan and Pakistan.
Dry air from the Arabian deserts may be unfavourable, but the weakening storm would hold itself together, riding as it does a very warm sea surface, low vertical wind shear and good 'window effect' on top.
The warm waters will continue to generate moisture and help with cloud-building, while the low wind shear (sudden change in wind direction and speed with height) will keep the storm tower in tact.
Gale-force winds
The ‘window effect’ on top of the structure would allow the system to ‘breathe in and out’ and sustain itself, though it would weaken progressively as dry desert infiltrates it even more.
Monsoon winds over the Arabian Sea would combine with inbound western disturbance to push ‘Vayu’ remnant into South-West Rajasthan and Indo-Pakistan border where it would fizzle out. ‘Vayu’ is seen progressively weakening as a severe cyclone and then as a conventional cyclone over the next two days, before negotiating the U-turn back to the North Gujarat coast and weakening.
By the time it reaches the coast, it would have been reduced to the status of a depression or a well-marked low-pressure area, still capable of generating moderate winds and rainfall over the adjoining area.
An IMD forecast for Saturday warned of gale-force winds clocking 120- 130 km/hr and gusting to 145 km/hr over the North Arabian Sea.
Monsoon advances
Squally winds speeding up to 55 km/hr and gusting to 65 km/hr are likely over the Gujarat coast. On Sunday, gale-force winds of up to 90 km/hr gusting to 100 km/hr are forecast over the North Arabian Sea, while strong winds speeding up to 50 km/hr gusting to 60 km/hr are likely over the Gujarat coast.
Meanwhile, on Friday, the IMD said that the monsoon has advanced into parts of the Central Arabian sea, remaining parts of Kerala, some parts of Karnataka, Tamil Nadu, most South-West Bay, more parts of Central and North Bay and North-East India.