KalBaishakhi 

It means a type of windy storm from the northwest. Literally 'kal' means "terrible," and 'baishakhi' refers to "something that happens in the month of Baishakh," that falls in the midtime of April. "KalBaishakhi" is a local term mainly used by the people of Bengal, Assam, and Odia. Its literal translation in English language is 'Northwesterlies' or 'Nor'wester'.

Although KalBaishakhi is a strong windy storm, many local people are benefited by it in their farming.

KalBaishakhi by typical Indian September 16, 2023

Kalboishakhi 

Also spelled Kalbaishakhi, a storm occasionally accompanied by thunder that takes place a few times every year during or slightly before the Bengali month of Baishakh (early April) in Bangladesh and West Bengal, following the hot and humid Choitra month ending an old year and symbolising the washing away of the grime of the old year.

Yeah, must be a Kalboishakhi cloud.

Kalboishakhi by A.Beng Ali April 20, 2011