The Fujiwhara effect, first described by Japanese meteorologist Sakuhei Fujiwhara (1921), refers to the mutual interaction between two nearby cyclonic vortices (typically within 1,400 km) which begin rotating around a common centre due to their overlapping wind fields.

Impact on Movement:

• The two systems orbit their centroid, often altering their original tracks unpredictably.
• The weaker cyclone may be absorbed, merged, or flung away by the stronger one.
• Forecasting becomes complex as steering currents get modified.

Impact on Intensity:

• Merger: Produces a single, larger and more intense storm with expanded wind field (e.g., Hurricane Iris–Humberto, 1995).
• Moisture-sharing: One cyclone may strip moisture from the other, weakening it while intensifying itself.
• Vertical shear: Interaction can enhance shear, sometimes disrupting organisation.

[Diagram: Two circles with curved arrows showing counter-rotation around a common central point]

Recent examples include Cyclones Seroja and Odette (2021). Understanding the Fujiwhara effect is vital for accurate track prediction, disaster preparedness and safeguarding coastal populations in cyclone-prone regions like the Bay of Bengal.