India Meteorological Department (IMD) has declared a pre-cyclone watch for the North Maharashtra and South Gujarat coasts after a low-pressure area formed as per its forecasts over the South-East and adjoining East-Central Arabian Sea (around Lakshadweep) on Sunday morning.
The low is likely to concentrate into a depression at a location over slightly to the North-West of its currently position as early as Monday and further as a cyclone the very next day, the second such rapidly evolving system this pre-monsoon season aftersuper cyclone Amphan in the Bay of Bengal.
Skymet sees onset, IMD rejects
This came on the morning after private weather forecaster Skymet Weather announced the onset of the monsoon over Kerala. But M Rajeevan, Secretary, Ministry of Earth Sciences, rejected it tweeting that the news of onset “is not correct. Monsoon has notarrived over Kerala. Follow @Indiametdept for authentic information.” Akhilesh Gupta, Adviser with the Department of Science and Technology and expert on climate change, agreed, saying the onset parameters have not been met yet over Kerala.
Meanwhile, squally winds speed reaching 45-55 km/hr gusting to 65 km have been warned of over the Lakshadweep area and along and off the Kerala coast during the next two days. It will gradually increase to gale strength (cyclonic at 65-75 km/hr) gustingto 85 km/hr along and off the Karnataka-South Maharashtra coasts from Tuesday morning and further to 90-100 km/hr gusting 110 km/hr (severe cyclone) along and off Maharashtra and Gujarat coasts from Wednesday morning.
A pale shadow of Amphan
Thus the brewing system may not reach anywhere the class-topping intensity of Category-5 storm on the Saffir-Simpson scale as Amphan, since it would be moving too fast over the waters for a comparably much shorter distance. This limits its stay over thewarm waters depriving it the benefit of deep convection (cloud-building) and the moisture it needs to fire itself up.
According to the IMD, the prospective cyclone would nearly northwards initially till Tuesday morning and then re-curve North-North-East, drop anchor off the North Maharashtra and South Gujarat coasts by Wednesday morning till when its forecasts are available.
Close shave likely for Mumbai
Its wind profile analysis suggests that the cyclone may cross the Mumbai-South Gujarat coast and the weakened storm may plough into South-East Rajasthan and further into Delhi. In this manner, the Arabian Sea system would bring rain along the West Coastand into parts of North-West India.
Some weather models suspect that the monsoon theatre would later open for the Bay to conjure up a circulation on the trail of Amphan. Preliminary outlook seeks to originate the system off Myanmar coast, before spinning in towards the Head Bay of Bengalby June 10, off West Bengal and Odisha coasts.
Monsoon advance prospects
The IMD also assessed that conditions are becoming favourable for advance of the monsoon into more parts of the South Arabian Sea, the Maldives-Comorin area, and South Bay of Bengal by Monday. Heavy rainfall is likely over parts of the South Peninsulauntil Tuesday with isolated heavy to very heavy rainfall over Kerala and Lakshadweep.
Meanwhile, an away-going depression from a twin low in the Arabian Sea was located on Sunday afternoon about 60 km West of Salalah (Oman) and 160 km East-North-East of Al-Ghaydah (Yemen). It may maintain the intensity into Monday morning and weaken gradually thereafter.
Heavy rain forecast
The IMD has forecast light to moderate rainfall at most places with isolated heavy to very heavy falls over Lakshadweep, Kerala and Coastal Karnataka on Monday and Tuesday. Light to moderate rainfall at most places with isolated heavy falls may lash SouthKonkan & Goa Sunday; and isolated heavy to very heavy falls on Tuesday.
Light to moderate rainfall at most places with isolated heavy to very heavy falls is forecast over Konkan & Goa on Tuesday and over South Konkan & Goa on Wednesday. Light to moderate rainfall at most places with heavy to very heavy falls at a few placesand extremely heavy falls at isolated places over North Konkan (including Mumbai) and North Madhya Maharashtra on Wednesday and Thursday.
Light to moderate rainfall at most places with isolated heavy to very heavy falls is forecast over South Gujarat, Daman, Diu, Dadra and Nagar Haveli on Wednesday and with heavy to very heavy falls at a few places and extremely heavy falls at isolated places on Thursday.