Return of the offshore trough along the West Coast combined with a fresh low-pressure area over the North-West Bay of Bengal is bringing rainfall to parts of Peninsular India as well.
India Met Department (IMD) located the offshore trough, a signature feature along the West Coast and harbinger of good monsoon conditions, covering the Kerala and Karnataka coasts.
Offshore trough
During a full-fledged and strong monsoon, this trough extends from South Gujarat to Kerala. It receives the moisture mopped up by the winds from the Arabian Sea, to be poured along the coast as rain.
The other important monsoon feature is the land-based monsoon trough lying over North-West and Central India that takes care of distribution of rainfall over most of the rest of the country.
This (Tuesday) morning, this trough passes through Bikaner, Alwar, Guna, Damoh, Daltongunj, Bankura and then into the centre of the 'low' over the North-West Bay of Bengal.
This trough is guiding the monsoon winds from the Bay of Bengal to feed in moisture to be distributed all along the states of Bengal, Jharkhand, East Madhya Pradesh, West Madhya Pradesh and Rajasthan.
Meanwhile, the IMD has already put under the 'low' in the Bay to intensify into being 'well-marked;' global weather models expect it to go on to become a monsoon depression.
Fuel to monsoon
This would only rev up the monsoon over East and adjoining Central India as well as along the West Coast over the next few days before pushing into North-West India as well.
Outlook until tomorrow (Wednesday) sees the possibility of fairly widespread to widespread rainfall with heavy falls over Coastal Andhra Pradesh, Telangana and Madhya Pradesh bringing parts of the peninsula also into focus.
The two days that follow would witness the heavy rain belt push towards the West into Gujarat even as the Arabian Sea sends out rain bands into the West Coast and Odisha in the East starts receiving fresh rain.
The nine hours ending on Tuesday morning have seen rains lash East Madhya Pradesh, Odisha, Chhattisgarh, plains of Bengal, Saurashtra, Kutch, West Rajasthan, West Madhya Pradesh and Kerala variously.
This morning, the monsoon has got additional props in the form of cyclonic circulations perched at vantage points over East Madhya Pradesh and Kutch in the West.
Looking on from higher in the atmosphere is an envelop of the East-West shear zone of monsoon turbulence where opposing meet and cedes space for monsoon systems ('low's or depressions) to prosper.
Rainy outlook
An outlook valid from September 8 to 10 predicts widespread to widespread rain with isolated heavy falls over East and adjoining North-West India, plains of North India, North-East India as well as along the West Coast.
Global forecasts continue to suggest that the monsoon might not lose its bite nor its appetite even after the current 'low' spends out itself over Central or adjoining North-West India.
The Climate Prediction Centre of the US National Weather Services suggests that the Bay of Bengal as well as the entire Northern half of the country would witness rain activity until mid-September.
There could be a short muted spell in between, but the US agency suggests that the Odisha coast might yet again reverberate with the buzz of another 'low' sooner than later.
This 'low' clambers up from Madhya Pradesh and sends out rain bends both into parts of Rajasthan as well as into Gujarat, Saurashtra and Kutch.
But the US National Centres for Environmental Prediction suspects that the monsoon would start withdrawing from West Rajasthan during this phase, limiting heavier rains to East Rajasthan, West Madhya Pradesh and South Gujarat.