The storm originated from an area of low pressure on September 24 that formed roughly 725 km (450 mi) east-northeast of Pohnpei.
Around the time the system was upgraded to a tropical storm by the JTWC, the JMA assessed it to have reached its peak intensity as a strong tropical depression with winds of 55 km/h (35 mph 10-minute sustained) and a barometric pressure of 999 mbar (hPa) [REF].