Kalbaisakhi struck a large area over east India yesterday, the 1st of this pre-monsoon season. Many parts of West Bengal, Odisha and Jharkhand were pounded by a line squall embedded with infamous norwesters, the violent thunderstorm accompanied with strong winds and severe lightning. Kolkata, Midnapore, Purulia, Digha, Bhubaneshwar, Keonjhargarh, Jamshedpur and Dumka were lashed with rain and thundershowers during the evening and night.
Norwesters or Kalbaisakhi, as they are locally called are violent thunderstorm of pre-monsoon season which invariably originate over the Chhota Nagpur area of Jharkhand and neighbourhood. These storms, black in appearance with roaring thunderous noise and scary lightning travel towards West Bengal, Odisha and Bangladesh with tremendous speed. These are accompanied with furious hurricane winds and keep regenerating as they travel southeastward. If given enough moisture, convection and heat, there could be tornadoes embedded in the tall clouds which carry devastating potential, albeit with narrow swathes.
With the advance of the season, these frightening storms keep becoming more and more powerful because of incremental heat. On freak occasions, this phenomenon attains catastrophic dimension to inflict loss of life and property spanning a large area. These are also punishing and hazardous for the aviators and they dread not to engage or even come nearer to such monsters.
Presently there is a cyclonic circulation over Jharkhand and Chhattisgarh with a trough extending across Madhya Pradesh and Maharashtra. This feature is fueled by moist winds from the Bay of Bengal by a displaced anticyclone over that area. Local heat is providing trigger in the afternoon hours to build deep clouds charged with millions of volts of electric potential. This potential is realized with lightning and thunder, more often along with high-velocity winds.
Norwester activity is expected today, stronger than the previous day, and will extend to the subsequent 24 hours, though on a milder note. The area which has to watch out today include Kolkata, Midnapore, Burdwan, Panagarh, Purulia, Bishnupur, Kalaikunda, Digha, Baripada, Cuttack, Bhubaneshwar, Puri, Chandbali and Balasore. Jamshedpur, Ranchi, Dumka and Chaibasa also need to exercise caution for thunderstorm and lightning.
