Tropical Cyclone Yasa Strengthens to Equivalent of Cat. 5 Hurricane

Tropical Cyclone Yasa strengthened to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday night. At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Yasa was located at latitude 14.6°S and longitude 174.5°E which put it about 285 miles (460 km) northwest of Nadi, Fiji. Yasa was moving toward the east at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h). The minimum surface pressure was 915 mb.

Tropical Cyclone Yasa intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale northwest of Fiji on Tuesday night. An eye with at diameter of 35 miles (55 km) was at the center of Yasa. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Yasa. Storms near the core generated strong upper level divergence which pumped mass away from the tropical cyclone in all directions.

Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of Tropical Cyclone Yasa. Winds to tropical storm force extended out 160 miles (260 km) from the center. The Hurricane Intensity Index (HII) for Tropical Cyclone Yasa was 35.0. The Hurricane Size Index (HSI) was 19.3 and the Hurricane Wind Intensity Size Index (HWISI) was 54.3. Tropical Cyclone Yasa was capable of causing regional catastrophic damage.

Tropical Cyclone Yasa will move through an environment capable of sustaining an intense tropical cyclone during the next 24 hours. Yasa 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. Tropical Cyclone Yasa will remain an intense tropical cyclone during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. If that happens, then an eyewall replacement cyclone could cause Yasa to start to weaken.

Tropical Cyclone Yasa will move around the southwestern part of a high pressure system near the Equator. The high will steer Yasa toward the southeast during the next 36 hours. On its anticipated track Tropical Cyclone Yasa could reach Fiji in less than 36 hours. Yasa will be the equivalent of a major hurricane when it approaches Fiji. The center of Tropical Cyclone Yasa could pass over Vanua Levu. Yasa could bring very strong winds and locally heavy rain to the some of the most populated parts of Fiji. Tropical Cyclone Yasa could cause severe damage to Fiji.

Elsewhere over the South Pacific Ocean, the center of Tropical Cyclone Zazu was moving away from of Niue. At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Zazu was located at latitude 21.7°S and longitude 169.6°W which put it about 130 miles (210 km) south of Niue. Zazu was moving toward the southeast at 14 m.p.h. (22 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 979 mb.