 On April 21 , a low pressure area separated from the prevailing westerlies about 600 miles ( 1 @,@ 100 km ) southeast of Bermuda , and developed into a subtropical depression at 1200 UTC . The system maintained a large comma @-@ shaped cloud pattern around the low @-@ level circulation . Operationally it was not classified until 27 hours later . Isolated from strong steering currents , the depression tracked northwestward at 12 mph ( 19 km / h ) , and intensified into a subtropical storm early on April 22 ; this was the first such storm on record in the month . It gradually became better organized , with a large convective band in the eastern semicircle . Reports from a nearby ship indicated peak winds of 50 mph ( 85 km / h ) , with swells of 64 @.@ 4 feet ( 19 @.@ 7 m ) . 
