The fifteenth named storm and fourteenth typhoon within the western Pacific Ocean that year, Amy developed from an area of low pressure near the Kwajalein Atoll on December 3.

Afterwards, Amy intensified to reach its peak intensity with maximum sustained winds of 220 km/h (140 mph) and a minimum barometric pressure of 950 mbar (hPa; 28.05 inHg) on December 8.

[nb 1] Over the ensuing two days, Amy moved over several islands in the central Philippines before emerging in the South China Sea on December 11 as the equivalent of a minimal typhoon.

Shortly after, the tropical cyclone executed a tight anticyclonic loop while oscillating in strength several times before eventually weakening and dissipating on December 17, just east of Vietnam.

Along the east coast of Leyte, where Amy initially struck, ninety percent of homes were destroyed, and a large swath of coconut plantations were wiped out.

Overall, Amy caused $30 million in damage,[nb 2] and at least 556 fatalities, though the final death toll may have been as high as 991, making the typhoon one of the deadliest in modern Philippine history.

Tracking westward, the Fleet Weather Center in Guam began to monitor vorticity for potential development,[nb 3] assigning the numeric designation 11122 to the tropical system.

Late on December 2, a routine weather reconnaissance flight unexpectedly intercepted the disturbance and detected unusually strong westerly winds, a characteristic typically indicative of a tropical cyclone.

After finding conclusive evidence of a closed low-pressure area, the Fleet Weather Center in Guam classified the disturbance as a tropical storm with winds of 100 km/h (60 mph).

[3] At 1200 UTC on December 8, Amy reached its peak intensity with winds of 220 km/h (140 mph) and a minimum barometric pressure of 950 mbar (hPa; 28.05 inHg), which would classify it as a modern-day Category 4 typhoon.

Over the next two days, the typhoon weakened and moved over several islands in the Philippines including Leyte, Cebu, and Panay before emerging into the South China Sea on December 11.

[4] Beginning on September 1, 1948,[5] the then-active volcano Mount Hibok-Hibok on Camiguin Island in the Philippines began to release lava in a series of eruption events which continued for the ensuing three years.

[6] On December 4, 1951,[7] a large, Peléan eruption event later rated between a 2 and 3 on the Volcanic Explosivity Index, sending pyroclastic flows and lahars down the northeast flank of the volcano.

[8] As the typhoon approached the archipelago, relief agencies were forced to divert aid operations to victims of the recent eruption, slowing the recovery process.

[9][10] Upon making landfall on south Samar on December 10, Hibok-Hibok erupted six times in rapid succession, worsening the effects of both the typhoon and the volcano.

[11] Strong winds displaced and destroyed residences and uprooted trees, while torrential rainfall caused rivers to overflow, resulting in the flooding of sugarcane fields and the washing away of bridges.