Tropical Cyclones Veronica and Trevor posed threats to Australia on Wednesday night.  Tropical Cyclone Veronica intensified very rapidly into the equivalent of a major hurricane on Wednesday off the coast of Western Australia.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Veronica was located at latitude 16.5°S and longitude 117.6°E which put it about 275 miles (445 km) north-northwest of Port Hedland, Australia.  Veronica was moving toward the south-southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 929 mb.  A Tropical Cyclone Watch was in effect for the portion of the coast from Pardoo to Mardie including Port Hedland and Karratha.

Tropical Cyclone Veronica intensified very rapidly during the past 24 hours.  Veronica strengthened from the equivalent of a tropical storm to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  A small pinhole 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 the circulation.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Veronica had a large circulation.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Veronica was 29.8.  The Hurricane Size Index (HSI) was 18.6 and the Hurricane Wind Intensity Size Index (HWISI) was 48.4.

Tropical Cyclone Veronica will remain in an environment favorable for strong tropical cyclones for several more days.  Veronica will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Veronica could strengthen into the equivalent of a Category 5 hurricane during the next 24 hours.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause fluctuations in the intensity of Veronica.

Tropical Cyclone Veronica will move around the western end of a subtropical ridge.  The ridge will steer Veronica toward the south-southwest.  Tropical Cyclone Veronica could move toward the south-southeast after it rounds the western end of the ridge.  On its anticipated track Tropical Cyclone Veronica could approach the coast of Western Australia in about three days.  Veronica could be the equivalent of a major hurricane at that time.

Tropical Cyclone Trevor moved over the eastern Gulf of Carpentaria on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Trevor was located at latitude 13.1°S and longitude 141.1°E which put it about 55 miles (90 km) southwest of Weipa, Australia.  Trevor was moving toward the southwest at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minium surface pressure was 988 mb.  A Tropical Cyclone Watch was in effect for the coast from Nhulunbuy to Karumba.

The circulation of Tropical Cyclone Trevor was gradually reorganizing as the center moved farther into the Gulf of Carpentaria.  Trevor will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Trevor will intensify during the next 48 hours and it could strengthen into the equivalent of a major hurricane.  On its anticipated track Trevor is forecast to approach the southwest of the Gulf of Carpentaria near Port McArthur in about 48 hours.