An area of thunderstorms, that generated mesoscale vortices during the past several days developed a persistent center of circulation on Friday and was classified as Tropical Storm Maysak (04W).  At 11:00 p.m. EDT on Friday the center of Tropical Storm Maysak was located at latitude 7.6°N and longitude 154.9°E which put it about 200 miles east of Chuuk and about 800 miles east-southeast of Guam.  Maysak was moving toward the west at 12 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and there were gusts to 65 m.p.h.  The minimum surface pressure was 989 mb.

Maysak formed over very warm Sea Surface Temperatures, but moderate upper level easterly winds were causing vertical wind shear and kept shearing the top off the circulation.  When the system moved further west, it moved into an area where the upper level winds were not as strong and a center of circulation develop and persisted.  The organization of the circulation has increased during the past 12 hours and Maysak has been intensifying.  It is expected to take a westerly track which would keep it in an area where the upper level winds should not be too strong.  Steady intensification is expected and rapid intensification is possible.  Maysak could become a typhoon in 24 hours and it could become the equivalent of a major hurricane in three or four days.

A subtropical ridge is steering Maysak toward the west and it is expected to keep steering it in that direction during the next few days.  The projected track takes Maysak very near Chuuk during the next 18 to 24 hours.  In a few days it is projected to pass between Guam and Yap and head in the general direction of the northern Philippines.