Tropical Cyclone Ula Intensifies, Could Threaten Vanuatu

Tropical Cyclone Ula moved into a more favorable environment and it intensified on Thursday.  At 4:00 p.m. EDT on Thursday the center of Tropical Cyclone Ula was located at latitude 18.7°S and longitude 174.4°E which put it about 260 miles (420 km) west of Suva, Fiji.  Ula was moving toward the northwest at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 982 mb.

Tropical Cyclone Ula has been moving slowly equatorward this week and it is now over slightly warmer Sea Surface Temperatures (SSTs).  Ula has extracted additional energy from the warmer water and the strength of thunderstorms near the core of the tropical cyclone increased.  The structure of the circulation is more symmetrical and an eyewall may be forming around the center of Ula.  The thunderstorms are also generating more upper level divergence, especially to the west of the center of the tropical cyclone.

Tropical Cyclone Ula is once again in a region that is favorable for intensification.  It is back over water where the SSTs are near 28°C.  An upper level ridge east of Ula is generating northeasterly winds over the top of the tropical cyclone, but the vertical wind shear is modest.  Tropical cyclone is likely to intensify further during the next 24 hours and it could become the equivalent of a hurricane on Friday.

Ula has been moving slowly northwest around the western end of a subtropical ridge.  The ridge is forecast to slowly strengthen during the next few days.  As the ridge strengthens it will start to steer Ula more toward the west.  On its anticipated track Tropical Cyclone Ula could move toward Vanuatu.