Tropical Cyclone Ula Intensifies Rapidly, Threatens Vanuatu

Tropical Cyclone Ula intensified rapidly on Friday as it started to move toward Vanuatu.  At 4:00 p.m. EDT on Friday the center of Tropical Cyclone Ula was located at latitude 18.7°S and longitude 173.5°E which put it about 545 miles (880 km) east-northeast of Noumea, New Caledonia.  Ula was moving toward the southwest at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 95 m.p.h, (155 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 963 mb.

Tropical Cyclone Ula intensified rapidly on Friday because it was in a very favorable environment.  Satellite images showed that there is a 15 mile (24 km) wide eye at the center of Ula.  Additional spiral bands are rotating outside the core of the tropical cyclone.  Ula has a very symmetrical structure.  Thunderstorms in the core of Ula are creating upper level divergence, especially to the west of the center of circulation.

Tropical Cyclone Ula is in an environment favorable for further intensification.  It is over water where the Sea Surface Temperature is near 28°C.  An upper level ridge to the east of Ula is producing northeasterly winds over the top of the tropical cyclone.  However, the vertical wind shear is only modest and further intensification is possible.  Tropical Cyclone Ula could become the equivalent of a major hurricane during the weekend.

A subtropical ridge east of Ula is starting to steer the tropical cyclone toward the southwest.  That general motion is expected to continue for the next several days.  On its anticipated track Tropical Cyclone Ula could approach the southern islands of Vanuatu in about 48 hours.  It could be a very strong tropical cyclone when it nears those islands.