The 1959 Pacific typhoon season was regarded as one of the most devastating years for Pacific typhoons on record, with China, Japan and South Korea sustaining catastrophic losses. It was an event in the annual cycle of tropical cyclone formation. The season had no official bounds, but tropical cyclones in the Western Pacific Ocean normally develop between May and October.
The scope of this article is limited to the Pacific Ocean, north of the equator and west of the International Date Line. Storms that form east of the Date Line and north of the equator are called hurricanes; see 1959 Pacific hurricane season. All typhoons were assigned a name and number. Tropical storms and tropical depressions formed in the entire west Pacific basin were assigned a name and number by the Joint Typhoon Warning Center, but the latter was not added if no reconnaissance missions were assigned. Systems handled by the responsibility of the United States Weather Bureau (USWB) and Fleet Weather Center (FWC) featured no number.
The 1959 Pacific typhoon season featured 24 tropical cyclones, though operationally 59 total areas of investigation were classified by the Joint Typhoon Warning Center (JTWC); three systems were handled by the responsibility of FWC at Pearl Harbor and the USWB at Honolulu. Three systems were questionable due to lack of reconnaissance aircraft use. In total, the season featured 65 tropical cyclones and areas of investigation operationally, including central Pacific Hurricane Patsy, which was operationally believed to have crossed the International Date Line into the western Pacific. The first annual tropical cyclone report for the western North Pacific Ocean was issued by the agency.
Season summary
Of the 33 tropical cyclones and 65 total areas of investigation, 18 storms attained typhoon status, which was below the yearly average of 19. At least nine other tropical systems never exceeded tropical storm intensity operationally. Most of the systems were noted to have developed within the typical spawning grounds for typhoons originating from easterly waves within the Intertropical Convergence Zone; the exceptions were Ellen and Georgia which developed from cold-core troughs extending southward into the tropical latitudes. Of the 18 typhoons that formed, five were first detected within of the island of Guam. 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 or greater. Of the total number of typhoons, 215 reconnaissance missions were flown into the storms, including 3,799 observations and 391 total fixes. The average track error for each advisory for storms during the season was for 12-hour forecasts and for 48-hour forecasts.
Systems Tropical Storm Ruby
The first tropical storm of the season was detected on February 27 about south of Yap with winds of . Moving erratically westward, Ruby maintained intensity until it passed south of Palau on February 28, when it began to weaken and move to the west-northwest. Ruby weakened to below tropical storm intensity on March 1 and then turned to the southwest. It dissipated later on the same day east of Mindanao.
Tropical Storm Sally
Three days after Ruby dissipated, the second tropical cyclone of the season was detected southeast of Majuro in the Marshall Islands with winds of After drifting northwest, Sally moved to the southwest on March 5 and then began to move westward, with its winds fluctuating to . Sally soon restrengthened on March 6, reaching a secondary peak of , and maintained its intensity for 18 hours as it moved steadily westward. After weakening on March 8, Sally briefly jogged to the west-northwest on March 9, and it began to re-intensify as it turned back to the west, quickly reaching its third peak of on March 10. Sally slowly weakened as it turned to the northwest and slowed in forward speed, with its winds decreasing to on March 11. After briefly restrengthening to on March 12, Sally turned to the west and quickly weakened to a tropical depression. The depression briefly turned to the west-southwest and dissipated on March 13 east of Mindanao.
Typhoon Tilda
The first typhoon of the season, Tilda originated from a closed circulation on the Intertropical Convergence Zone (ITCZ) south of Truk on April 12. Surface weather analysis determined that the center slowly moved westward, with surface reports indicating intensification. On April 14 a reconnaissance aircraft mission estimated winds of tropical storm force, assigning the storm its name. Whilst slowly steering northwestward on April 15, Tilda intensified into a typhoon after its northeast quadrant had sustained typhoon strength winds. Tilda then moved generally to the northwest with minor fluctuations on April 16 and on the following day, before turning northward on April 18, when it rapidly intensified.
Tilda attained its peak intensity of 145 mph (233 km/h) 400 miles (640 km) west of Guam on April 19, and it slowly weakened as it turned north-northeast and decreased in forward speed. The typhoon became quasi-stationary for 30 hours on April 20, weakening to a minimal typhoon in the process by the next day. After drifting under weak steering currents, Tilda accelerated to the north-northeast on April 22 and weakened to a tropical storm. Tilda dissipated on April 23 as it merged with the upper-level westerlies 130 miles (210 km) southwest of Iwo Jima, and overall stayed in the open ocean, causing no casualties.
Tropical Depression Violet
Being the first tropical depression monitored by the Joint Typhoon Warning Center (JTWC), Violet formed offshore Vietnam on June 27. The depression moved eastward at a speed of , before recurving westward the following day. The system remained weak, and by June 29, Violet dissipated inland.
Tropical Storm Wilda
A tropical depression formed on July 4 in the South China Sea west of Luzon. After briefly drifting northeast, the depression moved erratically northward on July 5, and it made landfall on mainland China east of Hong Kong on July 6. The system steered northeastward the following day while inland, before entering the East China Sea as an extratropical cyclone on July 8. Wilda made another landfall south of the Korean peninsula on the next day. The system then entered the Korea Strait and curved slightly northward. Wilda made two more landfalls at the Russian Far East, before dissipating on July 10.
Operationally the system was classified as a different tropical storm under the name Wilda, but post-analysis determined that tropical cyclone never attained winds of or greater. No reconnaissance aircraft investigated the system, which was one of only three disturbances not monitored during the season.
Tropical Depression Anita
Tropical Depression Anita was first observed on the vicinity of the Federated States of Micronesia on July 5. The system moved west before recurving east on July 6, and dissipated on that same day.
Typhoon Billie
An area of disturbed weather between Yap and Koror organized into a tropical depression on July 12. Moving to the northwest, it quickly strengthened, reaching tropical storm status, after an eye was found by a recon aircraft. On July 13, Billie intensified into a typhoon, before gradually strengthening further. After peaking at that day, Billie crossed over northeastern Taiwan, quickly weakened, and made landfall on eastern China on July 15. A weak trough brought the storm northeastward, where after weakening to a tropical storm, it traversed the Yellow Sea and crossed the Korean Peninsula, losing tropical characteristics on July 18.
Typhoon Billie caused extreme flooding in northeastern Taiwan, causing $500,000 in property damage, leaving 10,000 homeless in the capital city of Taipei, and killing 1. In Japan, the outer edges of the typhoon caused torrential rains, killing 44 and destroying more than 65,000 houses. Storms accompanying Billie and its remnants brought heavy rains and strong winds to South Korea, knocking out police telephone lines in Busan. The sudden onslaught of these storms caused a stampede of roughly 70,000 people out of a stadium, resulting in the indirect deaths of 68 people. Around 125 people were injured and 40 were hospitalized after the mass evacuation.
Typhoon Ellen
On August 1, a well-developed low pressure area and easterly wave accompanying the area was detected northwest of Guam. Following the discovery of an eye in the system, the area was designated as Tropical Depression Ellen by the JTWC at 06:00 UTC of August 2. Ellen intensified into a tropical storm four hours later, before consolidating further into a typhoon 24 hours after. On August 4, as Ellen moved northwestward, the storm reached its peak intensity while located south-southeast of Okinawa, attaining winds of . Taking an erratic path, Ellen proceeded to decelerate off the coast of Kyushu. A strong ridge to the north prevented Ellen from further movement for approximately 46 hours. During that time, a recon aircraft measured the very large eye at . The ridge then weakened, allowing the typhoon to accelerate in an east-northeast direction. By August 8, Ellen had weakened into a tropical storm. Ellen moved along the south coast of Japan, passing directly above its capital city Tokyo. The storm entered the open sea east of Honshu on August 9, before transitioning into an extratropical cyclone.
Ellen dropped up to of rainfall on Japan, killing 11 and causing severe rice crop damage. Ellen's greatest effect, however, was on Taiwan, where torrential rains associated with the typhoon caused disastrous flooding that killed nearly 700, left tens of thousands homeless, and destroyed much of the transportation infrastructure in the central and southwestern part of the island. Some locations received almost 50 inches of rain in three days, exceeding local annual average totals. The heaviest rain event was on August 7, when as much as of rain fell in the mountains and western plains, causing rivers and streams to burst through levees and flood thousands of hectares of farmland, washing away rural villages, and causing widespread urban flooding as well in Taichung and other cities. The economic impact was particularly extensive and long-lasting due to the widespread flooding of farmland. In Taiwan the event is remembered as the "Great August 7 Flood".
Tropical Depression Fran
First observed on August 11, Tropical Depression Fran was located north of Guam. The depression moved northwest before dissipating on August 12, under the influence of Typhoon Georgia's predominant circulation.
Typhoon Georgia
On August 12, Fran was split into two circulation centers by an upper-air polar trough. The new circulation consolidated into a tropical storm on August 13, receiving the name Georgia. Georgia quickly strengthened into a typhoon, and reached its peak intensity of in 06:00 UTC of that same day. The typhoon then proceeded to rapidly accelerate at a speed of for the next 24 hours. After crossing through the Japanese mainland, Georgia weakened into an extratropical cyclone on August 14.
Just 4 days after Ellen hit Japan, Typhoon Georgia hit the southeastern portion of the country. Georgia brought more heavy rains to the country, causing 246 fatalities and leaving over 50,000 homeless. Georgia caused torrential damage to Japan's railroad network, and combined with Typhoon Ellen, produced a damage total of $50 million (1959 USD).
Tropical Depression Hope