The India Meteorological Department (IMD) expects the monsoon to resume its much-delayed journey anytime now from the South Andaman Sea, Nancowry (Nicobar), and adjoining South-East Bay of Bengal, where it got stuck over the past 10 days.

The IMD set two-day windows repeatedly during this period for the monsoon to get going, which it refused to oblige. 

Delayed over Myanmar

On Monday, persistent clouding over the South-East Bay lent some credence to IMD’s revised assessment on the ground, backed by declaration of the onset over neighbouring Myanmar.

This itself has come at least seven to 10 days later than normal. The Myanmar Department of Meteorology and Hydrology expects two low-pressure areas to form over the Andaman Sea and the Bay during the next 4-5 days, of which one may intensify into a depression. 

Signal for Kerala?

Meanwhile, forecasts by a couple of US agencies of precipitable water in the lower atmosphere (signalling cloudiness and rain) seem to delay the onset of monsoon over Kerala in mainland India until a 10-day period between June 7 and 16.

This may at best fall within IMD’s onset window of June 4 (plus or minus four days), or even get slightly delayed further.

Western disturbances rule

Meanwhile to the West, an active western disturbance has triggered heavy rain, thunderstorms, lightning, hail and high winds over many parts of North-West India on Sunday.

It was seen anchored over Himachal Pradesh as a cyclonic circulation on Monday morning, even as a fresh disturbance develops over extreme East Iran, readying to enter Afghanistan.

The network of cyclonic circulations and troughs has to completely clear before the monsoon can entrench itself over the mainland.

This will not happen until deep western disturbances, with spurs that pierce into the South in the form of volatile weather-friendly troughs, with embedded cyclonic circulations, stop moving across the plains of North-West India.

Viewed from this perspective, it appears the incoming disturbance spotted over East Iran would be the last in the current series.