The Fujiwhara Effect refers to the binary interaction between two nearby tropical cyclones (typically within 1,400 km) where they begin to rotate around a common barycenter. Identified by Sakuhei Fujiwhara in 1921, it complicates modern meteorological forecasting.

Fujiwhara Effect Between Two Tropical Cyclones

Impact on the Movement of Tropical Cyclones

1. Cyclonic Orbiting: systems rotate counter-clockwise around each other in the Northern Hemisphere.

   • Eg: Interaction between Typhoons Hato and Pakhar (2017).

2. Track Deviation: causes unpredictable shifts from standard trajectories, challenging IMD landfall predictions.

3. Mutual Capture: the stronger system pulls the weaker one into its circulation path.

4. Accelerated Translation: interaction can significantly increase the forward speed of the involved systems.

5. Elastic Interaction: storms may approach and then veer away without merging, known as "bouncing."

Impact on the Intensity of Tropical Cyclones

1. Cyclone Cannibalism: the larger system absorbs the smaller one, potentially creating a Mega-cyclone.

   • Eg: Hurricane Wilma absorbing Tropical Storm Alpha (2005).

2. Vertical Wind Shear: the outflow of one storm can disrupt the core structure of the other, weakening it.

3. Resource Competition: dual systems compete for limited Ocean Heat Content, often dampening overall intensity.

4. Structural Deformation: interaction leads to asymmetric wind fields, reducing rotational velocity.

5. Sustained Longevity: merging can provide a fresh moisture influx, extending the storm's life cycle.

Enhanced Ensemble Forecasting and Satellite Meteorology are critical to mitigate these risks, aligning with SDG 13 (Climate Action) and NDMA guidelines for cyclone-resilient infrastructure.