Tropical Storm Jongdari Heads Toward China

Tropical Storm Jongdari headed toward China late on Tuesday.  After dropping heavy rain on parts of Honshu and Kyushu, former Typhoon Jongdari weakened to a tropical storm.  Jongdari then was caught by the circulation of an upper level low south of Japan and the tropical storm made a slow counterclockwise loop south of Kyushu.  Tropical Storm Jongdari completed the loop and moved west toward China on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Jongdari was located at latitude 30.0°N and longitude 126.7°E which put it about 360 miles (575 km) east-southeast of Shanghai, China.  Jongdari was moving toward the west at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 990 mb.

Tropical Storm Jongdari moved around the circulation of an upper level low south of Japan on Sunday and Monday.  Strong upper winds rotating around the upper level low caused vertical wind shear which disrupted the upper part of Jongdari’s circulation.  However, the integrity of the lower level circulation remained intact.  There is a well defined low level circulation with bands of showers and thunderstorms revolving around the center of circulation.  Stronger upper level winds have periodically sheared the tops off of the taller thunderstorms.  New thunderstorms were forming near the center of circulation but it is unclear if those storms will persist.

Tropical Storm Jongdari will move through an environment marginally favorable for intensification on Wednesday.  Jongdari will move over water where the Sea Surface Temperature is near 28°C.  However the upper level low south of Japan and an upper level ridge over East Asia will combine to produce strong easterly winds which will blow across the top of the circulation.  Those winds will cause strong vertical wind shear which will inhibit intensification.  Tropical Storm Jongdari could intensify a little during the next 24 hours.

Tropical Storm Jongdari will move south of a high pressure system near East Asia which will steer Jongdari in a general westerly direction.  On its anticipated track Tropical Storm Jongdari could approach the coast of China southeast of Shanghai in about 24 hours.  The center of Jongdari could be near Shanghai in about 36 hours.  Tropical Storm Jongdari will bring some gusty winds, but the greater risk will be locally heavy rainfall.  Heavy rain falling on very moist ground could cause flash floods over parts of eastern China.