URNT11 KMIA 272013 AF553 0502A ARTHUR OB 25 KMIA 97779 19474 60158 77800 55000 08011 57682 /4582 12460 81050 07575 SPIRAL CLOUD PATTERN SUGGESTS CLOSED CICULATION AT THE SFC AT 15D EG 50 MIN N 77 DEG 48 MIN W;