This system formed in the near equatorial trough southeast of Ponape a few days after Thad on October 20. The system moved northwest to just north of Ponape as it slowly developed. The disturbance strengthened into a tropical depression by October 22 and a tropical storm October 23 despite some northwesterly shear from Thad. As a minimal typhoon, Vanessa moved about south of Guam, where winds gusted to on Nimitz Hill. Damage on the island totaled US$1.7 million (1984 dollars), mainly to the banana crop. Moving west-northwest, Vanessa continued to strengthen, becoming a super typhoon. Super Typhoon Vanessa was the strongest typhoon of the season, reaching maximum sustained wind speeds of over the open waters of the West Pacific. At its peak, it had a pressure of 880 mb, only 10 millibars higher than the record-setting Typhoon Tip of 1979. Its central pressure fell 100 mb in 48 hours. The intense cyclone recurved on October 27 and October 28 as a cold front approached from the northwest. Vanessa slowly merged with the frontal boundary, becoming a storm-force extratropical cyclone late on October 30.