Norwester winds in India and Bangladesh, locally known as Kalbaishakhi, are severe pre-monsoon weather phenomena driven primarily by intense convective thunderstorm activity and atmospheric instability.
The retrieved papers consistently characterize Nor'westers (pre-monsoon thunderstorms in eastern India and Bangladesh) as mesoscale convective systems driven by intense atmospheric convection and instability. Multiple papers utilize thermodynamic indices and convective modeling to analyze these storm events. No papers refute the claim.