 Three of the typhoons developed at a slow rate, while three others rapidly intensified to typhoon status within hours.Only four typhoons were small in diameter, while at least three typhoons developed to large sizes and became the dominant tropical features during the season.Two of the typhoons — Joan and Vera — featured sea-level pressures below 900 millibars and were the most intense tropical cyclones during the season, each featuring winds of 190 mph (305 km/h) or greater.