Tag Archives: Pilbara

Tropical Cyclone Sean Rapidly Intensifies to Equivalent of Major Hurricane

Tropical Cyclone Sean rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean west of Australia on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Sean was located at latitude 23.0°S and longitude 110.4°E which put the center about 210 miles (340 km) west of Exmouth, Australia.  Sean was moving toward the southwest at 13 m.p.h. (21 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 936 mb.

A Warning was in effect for the portion of the coast from Onslow to Ningaloo.  The Warning included Exmouth.

Tropical Cyclone Sean rapidly intensified to the equivalent of a major hurricane west of Australia on Monday.  A small circular eye with a diameter of 10 miles (16 km) was at the center of Sean’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 Sean.  Storms near the core of Sean generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Tropical Cyclone Sean was relatively small.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Sean’s circulation.  Winds to tropical storm force extended out 110 miles (175 km) from the center of Tropical Cyclone Sean.

The Hurricane Intensity Index (HII) for Tropical Cyclone Sean was 25.1.  The Hurricane Size Index (HSI) was 12.6 and the Hurricane Wind Intensity Size Index (HWISI) was 37.7.  Tropical Cyclone Sean was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Tropical Cyclone Sean will move through an environment that will become unfavorable for intensification during the next 24 hours.  Sean will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the eastern part of an upper level trough over the South Indian Ocean.  The upper level trough will produce northwesterly winds are that will blow toward the top of Sean’s circulation.  Those winds will cause the vertical wind shear to increase.  The combination of cooler water and  more vertical wind shear will cause Tropical Cyclone Sean to weaken during the next 24 hours.

Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer Sean toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Sean will move a little farther away from the coast of Western Australia.

Bands in the eastern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause floods in some locations.  10.78 inches (274 mm) of rain has already fallen at the Karratha Airport.  4.37 inches (111 mm) of rain has already fallen at the Mardie Airport.

Flood Warnings were in effect for parts of the Pilbara and northern Gascoyne regions.  A Flood Warning was in effect for the Lyndon-Minilya Rivers. 

 

Tropical Cyclone Sean Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Sean intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday.  At 10:00 a.m. EST on Sunday the center of Tropical Cyclone Sean was located at latitude 20.5°S and longitude 113.9°E which put the center about 125 miles (200 km) north of Exmouth, Australia.   Sean was moving toward the west-southwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).   The minimum surface pressure was 978 mb.

A Warning was in effect for the portion of the coast from Whim Creek to Ningaloo.  The Warning included Karratha, Damoier, Onslow, and Exmouth.

Tropical Cyclone Sea intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday.  A circular eye with a diameter of 17 miles (28 km) formed at the center of Sean’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 Sean.  Storms near the core of Sean generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Sean was relatively small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Sean’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Sean.

Tropical Cyclone Sean will move through an environment favorable for intensification during the next 24 hours.  Sean will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the northern part of an upper level ridge northwest of Australia.  The upper level ridge will produce easterly winds are that will blow toward the top of Sean’s circulation.  Those winds will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Sean will intensify during the next 24 hours.

Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer Sean toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Sean will move parallel to the coast of Western Australia.  The center of Sean is forecast to remain over water.

Bands in the southern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause flash floods in some locations.  3.74 inches (95 mm) of rain fell at the Lombadina Airstrip.

A Flood Watch was in effect for the coastal parts of the Kimberley and the Pilbara Districts.  Catchments likely to be affected include the West Kimberley Rivers, the De Grey River, the Pilbara Coastal Rivers, the Fortescue River, the Onslow Coast, and the Lyndon-Minilya Rivers.

Tropical Cyclone Damien Brings Wind and Rain to Western Australia

Tropical Cyclone Damien brought wind and rain to Western Australia on Saturday.  At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Damien was located at latitude 21.7°S and longitude 117.0°E which put it about 60 miles (100 km) south-southeast of Karratha, Australia.  Damien was moving toward the south-southeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 962 mb.

A Warning was in effect for the portion of the coast of Western Australia from Whim Creek to Mardie including Karratha and Dampier.  Flood Warnings were in effect for the Fortescue River and the Coastal Pilbara Rivers.  A Flood Watch was in effect for the Pilbara and Gascoyne District.  An Initial Flood Warning was issued for the Ashburton River.

A weather station at Karratha reported a sustained wind speed of 90 m.p.h. (145 km/h or 78 kt) when the core of Tropical Cyclone Damien passed over it.  The station also reported a wind gust of 114 m.p.h. (183 km/h or 99 kt).  The weather station at Karratha measured 6.14 inches (156 mm) of rain during the passage of Damien.  The minimum pressure was 957 mb.

Tropical Cyclone Damien will move around the western end of a high pressure system over Australia.  The high will steer Damien toward the south-southeast during the next several days.  On its anticipated track Tropical Cyclone Damien could approach Tom Price and Paraburdoo in about 12 hours.  Damien will weaken slowly as it moves farther inland.  It will continue to produce strong winds capable of causing damage during the next 12 to 24 hours  Tropical Cyclone Damien could also drop locally heavy rain over parts of Western Australia during the next several days.

Strengthening Tropical Cyclone Damien Nears Western Australia

Strengthening Tropical Cyclone Damien neared the coast of Western Australia on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Damien was located at latitude 19.4°S and longitude 116.6°E which put it about 100 miles (160 km) north-northwest of Karratha, Australia.  Damien was moving toward the south-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 963 mb.

A Warning was in effect for the portion of the coast of Western Australia from De Grey to Onslow including Dampier, Karratha and Port Hedland.  Initial Flood Warnings were in effect for the Coastal Pilbara Rivers.  A Flood Watch was in effect for the Pilbara and Gascoyne District.

Tropical Cyclone Damien continued to strengthen quickly on Friday.  A circular eye developed at the center of Damien.  A narrow ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Damien.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Damien was relatively small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Damien was 16.5.  The Hurricane Size Index (HSI) was 9.9 and the Hurricane Wind Intensity Size Index (HWISI) was 26.4.  Damien was capable of causing localized serious damage.

Tropical Cyclone Damien will move through an environment favorable for intensification during the next 12 hours.  Damien will move over water where the Sea Surface Temperature is near 30°C.  It will move under the western end of an upper level ridge over Australia.  The ridge will produce northerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent Tropical Cyclone Damien from strengthening.  Damien could intensify into the equivalent of a major hurricane before it reaches the coast of Western Australia.

Tropical Cyclone Damien will move around the western end of a high pressure system over Australia.  The high will steer Damien toward the south during the next several days.  On its anticipated track the center of Tropical Cyclone Damien could make landfall on the coast of Western Australia near Dampier and Karratha in about 12 hours.  Damien will be capable of causing serious wind damage.  It will also produce a storm surge of up to 10 feet (3 meters) between Port Hedland and Dampier where the wind blows the water toward the coast.  The highest storm surge will occur near where the center makes landfall.  Tropical Cyclone Damien will also drop locally heavy rain and flash floods could occur in parts of Western Australia.