The third named storm of the 2021 Pacific typhoon season, Choi-wan originated from an area of low pressure, located south-southeast of Guam near a brewing system.

Although the storm was still located in the conductive conditions off the Philippine Sea while moving northwestward, a tropical upper tropospheric trough to the northeast halted the system's intensification, with Choi-wan's convection displaced to the south of its circulation on satellite imagery.

[4] On May 27, the Japan Meteorological Agency (JMA) and the Joint Typhoon Warning Center (JTWC) noted the persistence of an area of atmospheric convection about 425 nautical miles (787 km; 489 mi) south-southeast of Guam.

[5] The convection's nearby environment exhibited low vertical wind shear and warm 29–30 °C (84–86 °F) sea surface temperatures; ideal conditions for tropical cyclogenesis.

[8] The JTWC later followed with their own assessment, identifying the center of the newly developed tropical depression approximately 35 nautical miles (65 km; 40 mi) south-southeast of Angaur, Palau and assigning the designation 04W.

[20] Choi-wan then headed northwest while struggling to reorganize under the waters of the Tablas Strait, and then making a sixth landfall in Pola, Oriental Mindoro at 06:00 UTC.

[20] Continuing to move northwestward, the system made an eighth and final landfall in the Calatagan Peninsula in Batangas at 12:00 UTC on June 2 before exiting back into the South China Sea.

[21] Despite the system being predicted to dissipate in the area, warm sea surface temperatures aided Choi-wan to restrengthen to a tropical storm at 03:00 UTC on the next day.

[24] At 08:00 UTC on June 4, Choi-wan reentered the PAR before the system started to merge with an existing meiyu front which extends from China to the Japanese Islands[25] and at the same time, passing to the south of Taiwan.

[citation needed] While passing through the Ryukyu Islands, the JMA issued their final warning on Choi-wan as it transitioned to an extratropical storm[27] as it was still embedded in the front.

[citation needed] As Choi-wan (known locally as Dante) approached the Philippines, Tropical Cyclone Warning Signal (TCWS) #1 was issued in most of Luzon, the Visayas and Mindanao on May 31.

[29] Before the landfalls of Choi-wan, the NDRRMC conducted a risk assessment for the approaching storm on May 31 while over ₱1.105 billion worth of standby funds were dispersed by the country's Social Welfare and Development department for the evacuees.

[36] The province of Ilocos Norte in Northern Luzon were placed on heightened alert, also on the same day, following Choi-wan's approach as the storm progressed in the South China Sea.