The typhoon continued to intensify further , and early on October 12 reconnaissance aircraft recorded a worldwide record-low pressure of 870 mbar ( 870.0 hPa ; 25.69 inHg ) with winds of 305 km\/h ( 190 mph ) , when Tip was located about 840 km ( 520 mi ) west-northwest of Guam .
The typhoon continued to gain strength , and early on October 12 , Reconnaissance Aircraft recorded a worldwide record-low pressure of 870 mbar ( hPa , 25.69 inHg ) .