The south-west monsoon has advanced into some parts of Comorin area just to the south of Kerala, India Meteorological Department (IMD) said late on Friday.
The seasonal rains have also covered the remaining parts of south-east Bay, more parts of south-west Bay and east-central Bay and some parts of west-central and northeast Bay of Bengal.
Conditions are favourable for its further advance into some parts of south Arabian Sea, remaining parts of south-west Bay, some more parts of west-central, east-central and north Bay of Bengal during next three days.
Importantly, the monsoon has made an onset over Sri Lanka, the penultimate stopover before it breaks over Kerala, at least five days ahead of normal date of May 25.
If the current pattern sustains, the onset over Kerala should happen during the next week itself, as projected lately by the Climate Prediction Centre (CPC) of the US National Weather Services.
In what are first comments on the emerging weather in the Arabian Sea, the IMD may have just indicated that monsoon flows are in tact despite the nuisance value of erstwhile cyclone “Laila”.
The IMD also noticed persistence of convection over many parts of Bay of Bengal, apart from strengthening and deepening of the westerly winds and increase of the pressure gradient.
Meanwhile, the International Research Institute (IRI) for Climate and Society at Columbia University in its latest update indicated enhanced probability of excess rains for almost the entire western half of the country from July-August-September (JAS).
FLOODING RAINS?
According to experts, this might translate as flooding rain for these parts from mid-July onwards from a monsoon powered by an emerging La Nina in the equatorial and west Pacific.
Ahead of this, June-July-August (JJA) is forecast to feature enhanced probability for normal rainfall for the country as a whole, but west Uttar Pradesh might witness excess precipitation.
August-September-October (ASO), too, as in the case of JAS, is likely to see excess rains for the west of the country but with lesser north-to-south spread.
Probability for enhanced rains through this period would be high east Rajasthan, west Madhya Pradesh, western Maharashtra, north interior Karnataka, Rayalaseema, north Kerala and north Tamil Nadu.
Excess rains to the west and peninsular west of the country is known to carry the signature of a positive phase of the Indian Ocean Dipole (IOD), the Indian Ocean equivalent of the El Nino-La Nina phenomenon, but with a more direct impact on Indian monsoon.
IOD PHASE
The IOD is said to be positive (negative) when the sea-surface temperature is high over West Indian Ocean (East Indian Ocean). By the same token, a negative IOD is expected to have an adverse impact on concurrent rains over India.
Meanwhile on Friday, erstwhile cyclone ‘Laila' weakened twice over to become a depression and lay anchored over Kakinada in Andhra Pradesh, the IMD said in an update.
Current environmental conditions and numerical weather prediction models suggest that the system is likely to weaken further and move in a north-northeasterly direction.
Widespread rainfall with scattered heavy to very heavy falls is likely over north coastal Andhra Pradesh and adjoining Telangana during the next 12 hours and decrease in intensity thereafter.
Fairly widespread rainfall, with isolated heavy to very heavy falls, is likely over Orissa during the next one day and more. Isolated heavy rainfall is also likely over Gangetic West Bengal during next two days.
Squally winds reaching 45 to 55 km/hr in speed and gusting to 65 km/hr are likely along and off north Andhra Pradesh coast during the next 12 hours.
The sea condition will be rough to very rough along and off north Andhra Pradesh coast. Fishermen are advised not to venture into the sea off this coast.
The IMD continued to cite numerical weather model predictions suggesting the possibility of the remnant of ‘Laila' to crawl out into the North Bay of Bengal.
In that case, the system may intensify again over the sea. The system continues to be under constant watch.
