Kalbaisakhi Storm (Nor’westers)

Kalbaisakhi Storm (Nor’westers)

The Kalbaisakhi storm, scientifically known as Nor’westers, is a severe, localized pre-monsoon thunderstorm occurring in eastern and northeastern India and Bangladesh during March–May. Characterized by intense lightning, strong winds (up to 100 km/h), heavy rainfall, and occasional hailstorms, these storms develop rapidly and often cause significant damage.

Salient Features: They originate primarily over the Chotanagpur Plateau, where intense surface heating creates a low-pressure zone. The collision between dry northwesterly winds and moist air from the Bay of Bengal leads to atmospheric instability, forming towering cumulonimbus clouds. These storms typically move from northwest to southeast, hence the name “Nor’westers.”