Tropical Cyclone Jasper Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Jasper intensified to the equivalent of a major hurricane over the Coral Sea on Thursday. At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Jasper was located at latitude 14.0°S and longitude 156.6°E which put it about 755 miles (1220 km) east-northeast of Cairns, Australia. Jasper was moving toward the south at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 951 mb.

Tropical Cyclone Jasper continued to strengthen on Thursday and it reached an intensity equivalent to a major hurricane. A circular eye with a diameter of 30 miles (50 km) formed at the center of Jasper’s circulation. The eye was surrounded by a ring of 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 Jasper. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone in all directions. The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Jasper was symmetrical. Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Jasper’s circulation. Winds to tropical storm force extended out 180 miles (290 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Jasper was 22.0. The Hurricane Size Index (HSI) was 15.3 and the Hurricane Wind Intensity Size Index (HWISI) was 37.3. Tropical Cyclone Jasper was capable of causing regional major damage.

Tropical Cyclone Jasper will move through an environment somewhat favorable for intensification during the next 24 hours. Jasper will move over water where the Sea Surface Temperatures are near 29°C. It will move under the western part of an upper level ridge over the South Pacific Ocean. The upper level ridge will produce northerly winds that will blow toward the top of Jasper’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification but the shear may not be enough to stop Jasper from strengthening. Tropical Cyclone Jasper could intensify during the next 24 hours.

Tropical Cyclone Jasper will move around the northern part of a high pressure system over the South Pacific Ocean east of Australia. The high pressure system will steer Jasper toward the southwest during the next 24 hours. The high pressure system will steer Jasper toward the west during the weekend. On its anticipated track, Tropical Cyclone Jasper will approach the north coast of Queensland in a few days.