What is "whaitiri"

In Māori mythology, Whaitiri is a female deity, a personification of thunder, and the grandmother of Tāwhaki and Karihi. Whaitiri is the granddaughter of Te Kanapu, and the great-granddaughter of Te Uira, both of whom are personified forms of lightning (Reed 1963:158). In Maori mythology, there is also a male deity of thunder, Tāwhirimātea.