Dark monsoon clouds gather over the Kerala coastline as upper-level easterlies signal an unusually early arrival of the southwest monsoon in 2026. (Photo: PTI/IMD)

Rain building up: Monsoon winds reach southern India, showers next

India's southwest monsoon is showing early signs of advancement, with upper-level easterlies now covering Kerala, Karnataka, and the Andaman and Nicobar Islands as of May 17, 2026.

by · India Today

In Short

  • Upper-level monsoon easterlies now cover Kerala, Karnataka, and Andaman Islands.
  • The subtropical westerly jet has retreated north of the Himalayas.
  • IMD forecasts monsoon onset over Kerala around May 26, 2026.

The skies above India are quietly rearranging themselves. Upper-level winds high above southern India have begun to shift in ways that scientists say are a textbook signal of an advancing monsoon.

This year, it is happening earlier than usual.

THE WINDS ARE CHANGING

Upper-level easterlies associated with the southwest monsoon have now spread over Karnataka, Kerala, the Andaman and Nicobar Islands, Andhra Pradesh, the southern Bay of Bengal, and the southern Arabian Sea.

India's monsoon is coming early in 2026 (GIF: IMD)

This development would help the monsoon advance over the next two weeks and allow weather systems to track further north.

THE GIANT HIGHWAY IN THE SKY

High above the clouds, roughly 13 to 14 kilometres up, powerful winds blow from east to west during India’s monsoon season. Scientists call this the Tropical Easterly Jet, or TEJ.

Think of it as a giant atmospheric highway running overhead. When the TEJ is active, it creates upper-level divergence, a process where air at high altitude spreads outward in all directions.

An animated upper-tropospheric wind map shows the Tropical Easterly Jet flowing westward at altitudes of 13 to 14 kilometres over southern India, the southern Bay of Bengal, and the southern Arabian Sea. (Credit: Windy)

This acts like a vacuum, pulling air upward from the surface, feeding convection, or the rising of warm, moist air, and ultimately driving rainfall across the subcontinent.

A stronger TEJ generally means better monsoon rains.

It also steers low-pressure systems and cyclonic depressions forming over the Bay of Bengal northward and inland, spreading rains across a larger part of the country.

THE OTHER WIND THAT MATTERS

There is a second wind at play here. In the months before the monsoon, a powerful stream of winds blows from west to east high above northern India, acting like a heavy blanket pressing down on the atmosphere and preventing rain.

This is called the subtropical westerly jet. When summer arrives and temperatures rise sharply, this jet shifts northward, beyond the Himalayas, and its suppressing effect disappears. That is exactly what has happened now.

India's monsoon is already on the move. Upper-level winds high above southern India have shifted in ways scientists say signal an early onset. (Photo: PTI)

With this blanket lifted, the atmosphere over India is free to breathe again, allowing the monsoon to push northward without resistance.

The India Meteorological Department has forecast the monsoon's onset over Kerala around May 26, several days ahead of the long-term average of June 1.

- Ends