1990 Pacific typhoon season

A record workload for the typhoon warning center

The Joint Typhoon Warning Center issued 794 warnings on 32 western North Pacific tropical cyclones in 1990, the most warnings in its history for the basin. It kept watch for 165 days, against 154 in 1989 and 114 in 1988, and on 54 of those days it tracked two cyclones at once. Its own count was near the long-term mean of about 31 cyclones a year, with more typhoons than usual and fewer weak depressions.

Counts differ with the definitions behind them. JTWC classed 4 super typhoons, 17 other typhoons, 10 tropical storms and 1 depression, and its total includes Aka, which crossed the date line from the central Pacific already in warning. Other season lists give 31 named storms and 19 typhoons, drawing on both JTWC and Japan Meteorological Agency ten-minute winds. The site counts 29 tropical storms and 20 typhoons from US-agency one-minute winds during each system's tropical stage within the calendar year, and it puts accumulated cyclone energy at 330.1.

JTWC traced every 1990 cyclone to the monsoon trough or the near-equatorial trough. The center also posted its lowest 24-hour track errors on record for the basin that year, even though about 65 percent of the storms recurved, and it supported the Tropical Cyclone Motion experiment, TCM-90, with research aircraft flying into several typhoons.

A January typhoon and a wet June for Luzon and Taiwan

Typhoon Koryn formed below 5°N in the second week of January and reached typhoon strength on 14 January, the first of the year. JTWC noted that it turned north through the Mariana Islands and gave them their strongest sustained winds since a January typhoon in 1988. Three quiet months followed before Tropical Storm Lewis formed south of Chuuk in late April, and Typhoon Marian crossed the Philippines in mid-May before recurving toward Taiwan.

June brought four systems in quick succession as the monsoon trough stretched east. Tropical Storm Nathan crossed the Philippines and the South China Sea; Hong Kong's observatory, as quoted by JTWC, reported 13 people killed and 5 missing from Nathan, and rain along the southern China coast caused 10 more deaths. Typhoon Ofelia then swept past northern Luzon into Taiwan and eastern China. JTWC cited newspaper reports of more than 25 deaths in the northern Philippines, 17 dead and 23 missing in Taiwan, and at least 22 deaths in central China.

Typhoon Percy followed within a week, peaking at 115 kt in the archive on 25 June. It destroyed all crops on Ngulu south of Yap and killed one child on Palau, then struck northern Luzon, where JTWC reported at least 8 deaths from landslides and floods. Percy was the second storm in less than a week to batter that region.

A three-storm outbreak and floods in southern China

In July a large upper-level low settled west of the date line and the monsoon trough tilted northeast. Steve, Tasha and Vernon formed together in the third week of the month, the only three-storm outbreak JTWC recorded that year. Steve and Vernon ran north over open ocean; Steve reached 115 kt in the archive. Tasha turned west instead and came ashore about 140 km east of Hong Kong on 31 July.

Tasha's rain flooded Fujian and Guangdong. JTWC reported 69 deaths and 10,000 houses destroyed in Fujian, and 39 deaths, 335 injuries and 25,200 houses destroyed in Guangdong, with more than 5 million acres of farmland under water in each province. Its remnants drifted into the Yellow Sea and regenerated in the East China Sea as Winona, the only 1990 cyclone to form north of 25°N and the first typhoon of the year to hit Japan.

Typhoon Yancy, which JTWC judged its best-forecast storm of the year, triggered a monsoon surge over northern Luzon in mid-August, where at least six people died and more than 60,000 fled to evacuation centers. It then crossed northern Taiwan into China, where JTWC reported 216 deaths, 59 missing and losses of about $170 million.

Typhoon Abe followed in late August. Monsoon rains feeding it killed 12 people in Manila and 32 more in landslides north of the capital, and the Philippine Red Cross put the combined toll from Abe and Typhoon Becky at 85. JTWC also recorded one person swept out to sea on Okinawa, one death in Taiwan and 51 deaths near Shanghai after landfall. Abe's damage in China came to 3.5 billion yuan, about $742 million in 1990 US dollars.

Typhoon Flo and the TCM-90 flights

Six cyclones formed in September. Typhoon Flo, the fourth of them, passed near Guam and deepened rapidly as it approached Okinawa. A TCM-90 research aircraft measured 891 mb, which JTWC used for its 145 kt peak on 17 September; the archive lists 145 kt and 890 hPa, the lowest pressure of the season. Aircraft flew into Flo on more than three consecutive days during the experiment.

Flo passed about 110 km east of Okinawa, ending a drought there with 125 to 255 mm of rain. News reports cited by JTWC told of four deaths and three missing in Okinawan landslides. Flo came ashore on Honshu south of Osaka with winds JTWC estimated at 90 kt, well below its peak, and news reports called it the strongest typhoon to strike Honshu in 19 years. JTWC recorded 115 landslides, at least 32 dead, 6 missing and 90 injured there. Flo killed 40 people across Japan and caused damage of 132 billion yen, about $918 million in 1990 dollars.

Typhoon Gene and Typhoon Hattie followed Flo toward Okinawa and southern Japan within weeks. Gene killed four people in Kyushu and Honshu, according to JTWC. Hattie passed 55 km west of Okinawa, causing more than $1.7 million in damage, and a landslide on Shikoku struck a bus, killing three passengers.

A string of weak storms into Vietnam

Weaker systems kept crossing the South China Sea. Typhoon Becky, a midget storm, cut across northern Luzon and reached northern Vietnam in late August; later totals give 32 deaths. Typhoon Ed ran west for nearly two weeks from the Marshall Islands to northern Vietnam, where it killed at least 18 people and destroyed 4,500 homes. JTWC counted Tropical Storm Ira, which made landfall at Qui Nhon on 3 October, as the eighth cyclone to hit Vietnam that year.

Tropical Storm Jeana and Tropical Storm Lola followed the same westward path in October. Flooding tied to Ira killed at least 24 people in Thailand, and Lola, whose rain peaked near 800 mm, killed 23.

Mike, Page and a December strike on Guam

After two quiet weeks, Typhoon Mike formed in the eastern Caroline Islands in early November and reached 150 kt in the archive on 10 November, the season's strongest wind. It passed north of Palau, where Kayangel Island was almost destroyed. JTWC called Mike the most devastating typhoon to hit the Philippines since 1981; its report listed at least 250 dead or missing in the central islands, 2 million people in shelters, over 37,000 houses destroyed and more than 57 vessels sunk, mostly in the port of Cebu.

Later tallies grew. It caused more than 748 casualties in the Philippines and damage above $1.94 billion in 1990 US dollars. Mike later crossed the South China Sea toward Hainan and Vietnam. JTWC removed the name from its list, and the Philippine agency retired its local name, Ruping.

Typhoon Page lingered as a disturbance for nearly two weeks, then took only three days to reach 140 kt, and the archive records 910 hPa on 27 November. It turned north short of the Philippines and approached Japan at the end of the month. JTWC's Super Typhoon Owen began southwest of Hawaii, crossed the Marshall and Caroline Islands and destroyed nearly all homes and food crops on several atolls; two people died on Pohnpei when a live power line fell on them.

Typhoon Russ closed the year. It peaked at 125 kt in the archive and passed within 55 km of southern Guam on 20 December, the most severe storm to hit the island in 14 years. Guam was declared a disaster area on 24 December, with damage estimates as high as $120 million, and no one on the island died.