Upper-level winds slowly became more helpful for development , and on August 13 a large low pressure area formed about 90 miles ( 145 km ) north-northeast of CancÃ n , Quintana Roo . Upper-level winds gradually became more beneficial for development , and on August 13 a broad low pressure area formed about 90 miles ( 145 km ) north-northeast of CancÃ n , Quintana Roo .