Strengthening Tropical Cyclone Cook brought wind and rain to Vanuatu on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Cyclone Cook was located at latitude 17.8°S and longitude 167.4°E which put it about 65 miles (105 km) west of Port Vila, Vanuatu.  Cook was moving toward the south at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 985 mb.

Tropical Cyclone Cook strengthened quickly on Saturday as it moved through central portions of Vanuatu.  A primary rainband wrapped around the center of circulation and a clear area appeared intermittently on satellite imagery.  The strongest winds were occurring in a ring of thunderstorms around the forming eye.  The thunderstorms near the center were generating upper level divergence which was pumping out mass toward the southeast of Tropical Cyclone Cook.  Additional bands of showers and thunderstorms were forming in the eastern half of the circulation.  Winds to tropical storm force extend out about 150 miles (240 km) from the center of circulation.

Tropical Cyclone Cook will move through an environment that will be favorable for intensification during the next 24 to 36 hours.  Cook will move over water where the Sea Surface Temperature (SST) is near 30°C.  An upper level ridge to the east of Cook is generating northerly winds which are blowing toward the tropical cyclone, but the vertical wind shear is minimal.  Warm SSTs and little vertical wind shear will allow Tropical Cyclone Cook to intensify.  A period of rapid intensification could occur after the eye and eyewall are completely formed.  Tropical Cyclone Cook should become the equivalent of a hurricane/typhoon on Sunday.

Tropical Cyclone Cook is moving around the western end of a subtropical ridge.  The ridge is steering Cook a little to the west of due south.  A general south-southwesterly motion is expected to continue for another 24 to 36 hours.  On its anticipated track Tropical Cyclone Cook will move away from Vanuatu and toward New Caledonia.  Tropical Cyclone Cook could approach New Caledonia in about 36 hours.

The core of Tropical Cyclone Cook will continue to bring wind and rain to the area around Port Vila, Vanuatu on Sunday.  Storms in the outer rainbands will bring wind and rain to the southern parts of Vanuatu.  Tropical Cyclone Cook will be the equivalent of a hurricane/typhoon when it nears New Caledonia.  Cook will be capable of causing wind damage and heavy rain could cause flash flooding.