Strengthening Tropical Cyclone Debbie Nears Queensland

Tropical Cyclone Debbie strengthened on Sunday as it moved nearer to the coast of Queensland.  At 8:00 p.m. EDT on Sunday the center of Tropical Cyclone Debbie was located at latitude 19.1°S and longitude 150.4°E which put it about 155 miles (250 km) east-northeast of Bowen, Australia.  Debbie was moving toward the south-southwest at 5 m.p.h. (7 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 972 mb.

The primary rainband finally wrapped entirely around the center of circulation of Tropical Cyclone Debbie on Sunday and an eye formed.  The eye has a diameter of 35 miles (55 km).  A ring of strong thunderstorms surrounds the eye and the strongest winds are occurring in that eyewall.  Additional bands of showers and thunderstorms are revolving around the core of the circulation.  The circulation is symmetrical and well organized.  Thunderstorms around the core of the circulation are producing upper level divergence which is pumping out mass in all directions and the pressure is decreasing.

Tropical Cyclone Debbie will be moving through an environment favorable for intensification until it makes landfall in Australia.  Debbie will move over water where the Sea Surface Temperature is near 29°C.  The winds in the upper levels are weak and there is little vertical wind shear.  Tropical Cyclone Debbie will intensify until it makes landfall.  Since an eye has formed, Tropical Cyclone Debbie could intensify rapidly on Monday.

Tropical Cyclone Debbie is moving around a ridge over Australia.  The ridge steered Debbie toward the south-southwest on Sunday.  Debbie is expected to start to moving more toward the west-southwest on Monday.  On its anticipated track Tropical Cyclone Debbie could reach the coast of Queensland within 24 hours.  The landfall will likely occur between Ayr and Mackay with the highest probability of a landfall near Bowen.

The Hurricane Intensity Index (HII) for Tropical Cyclone Debbie is 11.5.  The Hurricane Size Index (HSI) is 18.3 and the Hurricane Wind Intensity Size Index (HWISI) is 29.8.  Those indices will increase as Tropical Cyclone Debbie strengthens on Monday.  Tropical Cyclone Debbie will bring strong winds, storm surge and locally heavy rainfall to coastal regions of Queensland.