NEW : Hurricane is expected to strengthen , forecasters say . NEW : Warning issued for Cayman Islands . NEW : The storm was moving north at nearly 12 mph ( 19 kph ) , and it is expected to strengthen and turn gradually northeast late Friday and Saturday . Watch in Cuba , Jamaica should monitor storm 's progress , officials say .
NEW : Hurricane is expected to strengthen , forecasters say . NEW : Warning issued for Cayman Islands . NEW : Watch in Cuba , Jamaica should monitor storm 's progress , officials say .