Tropical Storm Nangka Forms East of Kwajalein

Another tropical storm formed over the western North Pacific when a circulation developed west of the International Dateline and was designated as Tropical Storm Nangka (11W).  At 11:00 p.m. EDT on Friday the center of Tropical Storm Nangka was located at latitude 9.9°N and longitude 169.2°E which put it about 150 miles east-northeast of Kwajalein.  Nangka was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 992 mb.

Tropical Storm Nangka is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and upper level divergence is increasing.  However, there is sinking drier air north of the tropical storm and the circulation appears to be pulling some of the drier air into it.  As a result many of the stronger thunderstorms are occurring in the western half of the circulation.  The drier air could inhibit intensification in the short term.  The other favorable environmental factors are likely to produce intensification in the longer term once Nangka moves west of the drier air.

A subtropical ridge north of Nangka is expected to steer it in a west-northwesterly direction during the next few days.  On its expected track Nangka will bring wind and rain to a number of atolls in the Marshall Islands.  Nangka could approach the Mariana Islands in a few days.