熱帶氣旋形成警報
A low-pressure area formed south of Guam on September 22. On the next day, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the system. Owing to the low-level circulation center (LLCC) rapidly consolidating with convective banding, JTWC upgraded it to a tropical depression late on the same day. Overall, the environment was favorable for further development, with a developing anticyclone over the LLCC, weak vertical wind shear, and good poleward outflow due to a cold-core low north of the system.