Tropical Cyclone Narelle intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Narelle was located at latitude 13.6°S and longitude 147.2°E which put the center about 265 miles (425 km) north-northeast of Cairns, Australia.  Narelle was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 947 mb.

The Australian Bureau of Meteorology issued a Warning for the east coast of the Cape York Peninsula that is in effect from Lockhart River to Cape Tribulation.  The Warning includes Coen and Cooktown.  A Warning is also in effect for the west coast of the Cape York Peninsula from Mapoon to Pormpuraaw.  That Warning includes Weipa.

A Watch is in effect for the portion of the west coast of the Gulf of Carpentaria from south of Nhulunbuy to Port Mcarthur.

A circular eye with a diameter of 12 miles (19 km) was present at the center of Tropical Cyclone Narelle.  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 center of Narelle’s circulation.  Storms near the center of Narelle generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds around Tropical Cyclone Narelle was symmetrical.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Narelle’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Tropical Cyclone Narelle.

The Hurricane Intensity Index (HII) for Tropical Cyclone Narelle is 25.1.  The Hurricane Size Index (HSI) is 17.1 and the Hurricane Wind Intensity Size Index (HWISI) is 42.2.  Tropical Cyclone Narelle is similar in intensity to Hurricane Harvey when Harvey hit Texas in 2017.  Narelle is bigger than Harvey was.

Tropical Cyclone Narelle will move through an environment that will be favorable for intensification during the next 12 hours.  Narelle will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is over the northern part of the Coral Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Narelle is likely to intensify during the next 12 hours.

Tropical Cyclone Narelle will move around the northern side of a high pressure system that is over the Coral Sea.   The high pressure system will steer Narelle toward the west during the next 24 hours.   On its anticipated track, Tropical Cyclone Narelle will approach the coast of Queensland near Cape Melville in 12 hours.

Tropical Cyclone Narelle will bring very strong winds and heavy rain to the northern part of the Cape York Peninsula later this week.  Narelle will be capable of causing severe damage.  Heavy rain is likely to cause flash floods in some locations.  Tropical Cyclone Narelle could also cause a storm surge of up to 13 feet (4 meters) along the coast near where the center of circulation makes landfall.

Flood Watches are in effect for parts of the Cape York Peninsula and the North Tropical Coast of Queensland.