Typhoon tracks (yellow dotted lines) and positions of the observation sites Zhizai Island and Sanjiao Island. The distance between northeastern coast of Macao and the Sanjiao Island is about 12 km, and the shortest distance between the 100 m high observation tower sites at Zhizai Island and the coast is 4.5 km. The center of typhoon Nuri passed the tower at 18:50 on August 22, 2008, and the shortest distance from Sanjiao Island to typhoon center is about 32 km. The center of typhoon Hagupit passed the tower at 05:10 on September 24, 2008, and the shortest distance from Zhizai Island to typhoon center is about 8.5 km.
