Authorities yesterday sounded an alert in Andhra Pradesh and adjoining Tamil Nadu as cyclonic storm 'Vardah' over the Bay of Bengal has turned into a "very severe" one. The storm is likely to cross north Tamil Nadu and south Andhra Pradesh coast by this after-noon, said Indian Meteorological Department yesterday. The Met office has forecast light to moderate rains at many places with isolated heavy to very heavy falls over south Andhra coast and north coastal Tamil Nadu from yesterday evening for subse-quent36hours.