Rain bands
Also called: Spiral bands · Topic: Air Masses, Fronts, Cyclones and Thunderstorms · NCERT: Class 11, Ch 9 "Atmospheric Circulation and Weather Systems"
Meaning
Rain bands are long, curved bands of cloud that spiral outward from the eye wall of a tropical cyclone. They are made of shower clouds and thunderclouds, with gaps of lighter weather in between. As each band passes, it brings a burst of heavy rain and strong gusts of wind. Because they reach far from the centre, rain bands give the first sign of a cyclone, hours before its centre arrives.
Example
As Cyclone Amphan moved towards the West Bengal–Bangladesh coast in May 2020, its outer rain bands brought heavy rain and gusty winds to Kolkata before the centre made landfall near the Sundarbans.
Don't confuse with
- Eye wall: the solid ring of cloud right around the eye. It has the strongest winds and heaviest rain. Rain bands lie outside it and are weaker.