at the time of landfall at cape flattery at 12 april 22:00 ( unk ) , the cyclone Catastrophe 's dvorak intensity Cause_change_of_position_on_a_scale was approximately unk , consistent with a weak category 4 system , and considerably lower than the unk observed Scrutiny when the system was at its peak intensity Cause_change_of_position_on_a_scale .