Typhoon Mitag was passing just to the east of China on Monday night. At 11:00 p.m. EDT on Monday the center of Typhoon Mitag was located at latitude 27.7°N and longitude 122.2°E which put it about 250 miles (400 km) south-southeast of Shanghai, China. Mitag was moving toward the north-northeast at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h). The minimum surface pressure was 970 mb.
Typhoon Mitag began to weaken later on Monday. An upper level trough over eastern Asia was producing southerly winds which were blowing toward the top of the circulation. Those winds were causing moderate vertical wind shear. The circulation around Mitag was drawing drier air from Asia into the southern and western parts of the typhoon. There was still an eye at the center of Typhoon Mitag. However the ring of strong thunderstorms around the eye weakened. The stronger bands of showers and thunderstorms were in the northern half of the circulation. Bands in the southern half of the circulation consisted primarily of showers and lower clouds. Winds to typhoon force extended out 60 miles (95 km) from the center of circulation. Winds to tropical storm force extended out 215 miles (345 km) from the center.
Typhoon Mitag will likely to continue to weaken during the next several days. The upper level trough will continue to cause moderate vertical wind shear. The circulation around Mitag will also continue to draw drier air from Asia into the typhoon. Typhoon Mitag will continue to weaken slowly and it could weaken to a tropical storm within 24 hours.
The upper level trough will steer Typhoon Mitag toward the north-northeast during the next 12 to 24 hours. Mitag will turn more toward the northeast in a day or so. On its anticipated track Typhoon Mitag will pass to the east of Ningbo and Shanghai. Mitag could approach South Korea in about 36 hours. It will likely be a tropical storm by that time, but Mitag could drop locally heavy rain over South Korea.
Tropical Storm Jongdari made landfall south of Shanghai on Thursday, while Tropical Storm Shanshan formed northeast of Guam. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Jongdari was located at latitude 30.7°N and longitude 121.4°E which put it about 40 miles (65 km) south of Shanghai, China. Jongdari was moving toward the west at 19 m.p.h. (30 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 994 mb.
The center of Tropical Storm Jongdari made landfall on the east coast of China near Zhoushan and Ningbo on Thursday. Jongdari retained a distinct low level center of circulation while it made landfall. The tropical storm brought gusty winds to the coast of Zhejiang and Shanghai Shi provinces. Tropical Storm Jongdari dropped locally heavy rain over parts of those provinces and some flooding could occur. The center of Jongdari will move quickly toward Hangzhou and the risk of flooding will continue as the tropical storm moves inland and weakens.
Elsewhere over the Western North Pacific Ocean, Tropical Storm Shanshan formed northeast of Guam. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Shanshan was located at latitude 17.9°N and longitude 150.1°E which put it about 460 miles (740 km) northeast of Guam. Shanshan was moving toward the west-southwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (65 km/h). The minimum surface pressure was 998 mb.
A distinct low level center of circulation formed in a cluster of thunderstorms east of the Northern Marianas on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Shanshan. The circulation of Shanshan was still organizing. Several bands of showers and thunderstorms developed southwest of the center of circulation. Bands northeast of the center consisted mostly of showers and lower clouds. Storms near the center of circulation started to generate upper level divergence.
Tropical Storm Shanshan will move through an environment favorable for intensification. Shanshan will move over water where the Sea Surface Temperature is near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Shanshan will intensify and it could strengthen into a typhoon during the weekend.
Tropical Storm Shashan will move around the western end of a subtropical high pressure system. The high will steer Shanshan in a general northwesterly direction during the next 12 to 24 hours. It will turn more toward the north during the weekend. On its anticipated track Tropical Storm Shanshan will move near the Northern Marianas during the next 24 to 36 hours.