A tropical cyclone was developing east of Vanuatu on Friday night. The large low pressure system contained two smaller circulation. One circulation was already designated at Tropical Cyclone 04P by the Joint Typhoon Warning Center. At 10:00 p.m. EST on Friday the center of Tropical Cyclone 04P was located at latitude 14.9°S and longitude 175.8°E which put it about 220 miles (360 km) north-northwest of Nadi, Fiji. It was moving toward the west-southwest at 17 m.p.h. (28 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 994 mb.

A second larger circulation designated Invest 91P was located northwest of Tropical Cyclone 04P. At 10:00 p.m. EST on Friday the center of Invest 91P was located at latitude 12.6°S and longitude 170.1°E which put it about 310 miles (500 km) east-northeast of Vanuatu. It was moving toward the east at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1002 mb.

Tropical Cyclone 04P and Invest 91P will rotate around each other during the next several days. The circulation around Invest 91P was larger, but the wind speeds were weaker. Upper level divergence from Invest 91P was creating vertical wind shear over Tropical Cyclone 04P. The shear was inhibiting the intensification of Tropical Cyclone 04P. The two circulations are forecast to eventually merge, but numerical models differ on which circulation will become the dominant center of circulation.

The larger environment around Tropical Cyclone 04P and Invest 91P will be favorable for intensification after the two circulations merge. The merged tropical cyclone will be over water where the Sea Surface Temperature is near 29°C. It will be in a region where the upper level winds are weak and there will be little vertical wind shear. Once Tropical Cyclone 04P and Invest 91P consolidate into a single circulation, then the tropical cyclone will intensify. It could strengthen into the equivalent of a hurricane/typhoon early next week.

Tropical Cyclone 04P and Invest 91P will rotate clockwise around each other during the weekend. The overall circulation containing the two systems is forecast to drift slowly toward the south during the next several days. On its forecast track the developing tropical cyclone will move slowly toward the south between Fiji and Vanuatu.