&sq=Qlik&lang=&file=File:Choi-wan_2009-09-16_0125Z.jpg) Typhoon Choi-wan at peak intensity on September 16 | |
| Meteorological history | |
|---|---|
| Formed | September 11, 2009 |
| Extratropical | September 20, 2009 |
| Dissipated | September 21, 2009 |
| Violent typhoon | |
| 10-minute sustained (JMA) | |
| Highest winds | 195 km/h (120 mph) |
| Lowest pressure | 915 hPa (mbar); 27.02 inHg |
| Category 5-equivalent super typhoon | |
| 1-minute sustained (SSHWS/JTWC) | |
| Highest winds | 260 km/h (160 mph) |
| Lowest pressure | 918 hPa (mbar); 27.11 inHg |
| Overall effects | |
| Fatalities | None |
| Damage | Minimal |
| Areas affected | Northern Mariana Islands |
| IBTrACS | |
Part of the 2009 Pacific typhoon season | |
Typhoon Choi-wan was a powerful typhoon that became the first Category 5-equivalent super typhoon to form during the 2009 Pacific typhoon season. Forming on September 11, 2009, about 1,100 km (700 mi) to the east of Guam, the initial disturbance rapidly organized into a tropical depression. By September 12, the depression intensified into a tropical storm, at which time it was given the name Choi-wan. The following day, rapid intensification took place through September 14. Choi-wan attained its peak intensity on September 15, as it moved through the Northern Mariana Islands with the Japan Meteorological Agency reporting peak 10-minute sustained winds of 195 km/h (121 mph). Additionally, the Joint Typhoon Warning Center reported the storm to have attained 1-minute sustained winds of 260 km/h (160 mph). The typhoon remained very powerful until September 17 when the storm's outflow weakened. The typhoon underwent an eyewall replacement cycle, leading to intensity fluctuations. By September 19, Choi-wan rapidly weakened as strong wind shear caused convection to diminish. The following day, the system transitioned into an extratropical cyclone and dissipated several hours later over open waters.
Despite the intensity of Choi-wan when it passed through the Northern Mariana Islands, no casualties were reported. However, following the storm, the United States Navy deemed that the island of Alamagan was uninhabitable, with all but one of the structures completely destroyed and most of the islands' trees downed. In response to this, all residents on the island were evacuated to nearby Saipan.