Tag Archives: Port Hedland

Tropical Cyclone Zelia Brings Wind and Rain to Western Australia

Tropical Cyclone Zelia brought wind and rain to Western Australia on Friday.  At 7:00 a.m. EST on Friday the center of Tropical Cyclone Zelia was located at latitude 21.1°S and longitude 119.6°E which put the center about 10 miles (20 km) west-northwest of Marble Bar, Australia.  Zelia was moving toward the south-southeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 965 mb.

The center of Tropical Cyclone Zelia made landfall on the coast of Western Australia about 45 miles (75 km) northeast of Port Hedland on Thursday night.  Zelia was the equivalent of a major hurricane at the time of landfall.  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).

At the time of landfall winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Zelia’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Tropical Cyclone Zelia.

The Hurricane Intensity Index (HII) for Tropical Cyclone Zelia was 25.1 . The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 39.0.  Tropical Cyclone Zelia was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Tropical Cyclone Zelia brought strong winds and heavy rain to parts of Western Australia east of Port Hedland.  A weather station in Port Hedland reported a sustained wind speed of 50 m.p.h. (80 km/h).  The weather station reported a wind gust of 75 m.p.h. (120 km/h).  The weather station also reported 6.14 inches (156 mm) of rain.

A Flood Warning is in effect for the De Grey River.  A Flood Warning is in effect for the Pilbara coastal Rivers.

Flood Watches are in effect for the Onslow coast, the Fortescue River, the Ashburton River, the Gascoyne River, and parts of the Sandy Desert.

Tropical Cyclone Zelia will move around the northwestern side of a high pressure system over Australia.  The high pressure system will steer Zelia toward the south during the next 24 hours.  On its anticipated track, the center of Tropical Cyclone Zelia will pass between Nullagine and Munjina.

Tropical Cyclone Zelia will weaken steadily as it moves inland over Western Australia.  Zelia will continue to bring strong winds and heavy rain to parts of Western Australia as it weakens.  Heavy rain could cause additional flooding in some locations.

Tropical Cyclone Zelia Approaches Coast of Western Australia

Tropical Cyclone Zelia was approaching the coast of Western Australia near Port Hedland on Thursday night.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Zelia was located at latitude 19.8°S and longitude 118.7°E which put the center about 55 miles (90 km) north of Port Hedland, Australia.  Zelia was moving toward the south-southeast at 5 m.p.h. (8 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 938 mb.

Concentric eyewalls developed at the center of Tropical Cyclone Zelia on Thursday.  The inner end of a rainband wrapped around the original eye and eyewall.  The inner eyewall had a diameter of 15 miles (24 km). The outer eyewall had a diameter of 38 miles (61 km).  The development of concentric eyewalls halted the intensification of Tropical Cyclone Zelia.

Bands of showers and thunderstorms were revolving around the concentric eyewalls at the center of Tropical Cyclone Zelia.  Storms near the center of Zelia generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass in the upper levels was nearly the same as the inflow of mass in the lower levels of the atmosphere.  So, the surface pressure remained fairly constant.

The circulation around Tropical Cyclone Zelia was symmetrical.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Zelia’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Tropical Cyclone Zelia.

The Hurricane Intensity Index (HII) for Tropical Cyclone Zelia was 25.1.  The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 39.0.  Tropical Cyclone Zelia was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Tropical Cyclone Zelia will move through an environment favorable for intensification during the next few hours.  Zelia will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that extends from Australia to the South Indian Ocean.  The upper level winds are weak near the middle of the middle of the ridge and there will be little vertical wind shear.  Even though Tropical Cyclone Zelia will move through a favorable environment, the concentric eyewalls are likely to prevent any significant intensification.

Tropical Cyclone Zelia will move around the northwestern side of a high pressure system over Australia.  The high pressure system will steer Zelia slowly toward the south during the next 24 hours.  On its anticipated track, the center of Tropical Cyclone Zelia will make landfall on the coast of Western Australia near Port Hedland in a few hours.

Tropical Cyclone Zelia will bring strong winds and heavy rain to parts of Western Australia near Port Hedland.

A Warning is in effect for the portion of the coast from Wallal Downs to Roebourne.   The Warning includes Port Hedland and De Grey.  The Warning extends inland to Marble Bar, Millstream, Nullagine, Tom Price, and Paraburdoo.

Heavy rain is likely to cause floods in some locations.

A Flood Warning is in effect for the De Grey River.  A Flood Warning is in effect for the Pilbara coastal Rivers.

Flood Watches are in effect for the Onslow coast, the Fortescue River, the Ashburton River, the Gascoyne River, and parts of the Sandy Desert.

Tropical Cyclone Zelia Rapidly Intensifies to Equivalent of Major Hurricane

Tropical Cyclone Zelia rapidly intensified to the equivalent of a major hurricane near the coast of Western Australia on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Zelia was located at latitude 19.1°S and longitude 118.1°E which put the center about 80 miles (130 km) north-northwest of Port Hedland, Australia.  Zelia was nearly stationary.  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 940 mb.

Tropical Cyclone Zelia rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Thursday.  A small circular eye with a diameter of 12 miles (19 km) formed at the center of Zelia’s circulation.  A ring of thunderstorms surrounded the center of Zelia and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Zelia.  Storms near the core 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 Zelia was symmetrical.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Zelia’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Zelia.

The Hurricane Intensity Index (HII) for Tropical Cyclone Zelia was 28.3.  The Hurricane Size Index (HSI) was 14.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.4.

Tropical Cyclone Zelia will move through an environment favorable for intensification during the next 24 hours.  Zelia will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that extends from Australia to the South Indian Ocean.  The upper level winds are weak near the middle of the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Zelia will continue to intensify during the next 24 hours.  Zelia could intensify rapidly at times.  Tropical Cyclone Zelis could strengthen to the equivalent of Category 5 hurricane on the Saffir-Simpson Scale.

Tropical Cyclone Zelia will move around the northwestern side of a high pressure system over Australia.  The high pressure system will steer Zelia slowly toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone will move closer to the coast of Western Australia.  Zelia could approach the coast between Port Hedland and Dampier in 36 hours.

Tropical Cyclone Zelia will bring strong winds and heavy rain to parts of Western Australia.

A Warning is in effect for the portion of the coast from Bidyadanga to Dampier.  The Warning includes Port Hedland, Karratha, De Grey, and Wallal Downs.  The Warning extends inland to Marble Bar.

A Watch is in effect for the portion of the coast from Dampier to Mardie.  The Watch extends inland to Nullagine and Tom Price.

Heavy rain is likely to cause floods in some locations.

A Flood Warning is in effect for the De Grey River.

Flood Watches are in effect for the Pilbara coastal Rivers, the Onslow coast, the Fortescue River, the Ashburton River, and parts of the Sandy Desert.

Tropical Cyclone Zelia Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Zelia intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia early on Wednesday.  At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Zelia was located at latitude 19.1°S and longitude 118.6°E which put the center about 80 miles (130 km) north of Port Hedland, Australia.  Zelia was moving toward the south-southwest at 3 m.p.h. (5 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.

Tropical Cyclone Zelia exhibited signs of rapid intensification early on Wednesday.  The inner end of a rainband wrapped around the center of Zelia’s circulation.  A small eye appeared to be forming at the center of Tropical Cyclone Zelia.  A ring of thunderstorms surrounded the center of Zelia and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Zelia.  Storms near the core 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 Zelia was symmetrical.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Zelia’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Zelia.

Tropical Cyclone Zelia will move through an environment favorable for intensification during the next 24 hours.  Zelia will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that extends from Australia to the South Indian Ocean.  The upper level winds are weak near the middle of the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Zelia will intensify during the next 24 hours.  Zelia could intensify rapidly at times.  Tropical Cyclone Zelis could strengthen to the equivalent of a major hurricane.

Tropical Cyclone Zelia will move around the northwestern side of a high pressure system over Australia.  The high pressure system will steer Zelia slowly toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone will move closer to the coast of Western Australia. Zelia could approach the coast between De Grey and Dampier in 36 hours.

Tropical Cyclone Zelia will bring strong winds and heavy rain to parts of Western Australia.

A Warning is in effect for the portion of the coast from Bidyadanga to Dampier.  The Warning includes Port Hedland, Karratha, De Grey, and Wallal Downs.  The Warning extends inland to Marble Bar.

A Watch is in effect for the portion of the coast from Dampier to Mardie.  The Warning extends inland to Nullagine.

Heavy rain is likely to cause floods in some locations.

A Flood Warning is in effect for the De Grey River.

Flood Watches are in effect for the Pilbara coastal Rivers, the Onslow coast, the Fortescue River, the Ashburton River, and parts of the Sandy Desert.

Elsewhere over the South Indian Ocean, Tropical Cyclone Vince made a transition to an extratropical cyclone and Tropical Cyclone Taliah continued to move farther away from the Cocos Islands.

At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Taliah was located at latitude 18.2°S and longitude 90.3°E which put the center about 565 miles (915 km) south-southwest of the Cocos Islands.  Taliah was moving toward the southwest at 15 m.p.h. (24 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 984 mb.

Tropical Low Strengthens to Tropical Cyclone Zelia

A former Tropical Low near the coast of Western Australia strengthened to Tropical Cyclone Zelia on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Zelia was located at latitude 18.7°S and longitude 118.9°E which put the center about 110 miles (175 km) north of Port Hedland, Australia.  Zelia was moving toward the south-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 991 mb.

A former Tropical Low near the coast of Western Australia strengthened on Tuesday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Zelia.  More thunderstorms formed near the center of Zelia’s circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Zelia.  Storms near the center of Zelia 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 Zelia became more symmetrical on Tuesday.  Winds to tropical storm force extended out 145 miles (230 km) from the center of Zelia’s circulation.

A weather station on Rowley Shoals measured a sustained wind speed of 47 kt (54 m.p.h. or 87 km/h) and a wind gust of 64 kt (74 m.p.h. or 119 km/h).

Tropical Cyclone Zelia will move through an environment favorable for intensification during the next 24 hours.  Zelia will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that extends from Australia to the South Indian Ocean.  The upper level winds are weak near the middle of the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Zelia will intensify during the next 24 hours.  Zelia is likely to strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Zelia will move around the western side of a high pressure system over Australia.  The high pressure system will steer Zelia slowly toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone will move closer to the coast of Western Australia.  Zelia could approach the coast between Wallal Downs and Port Hedland in 48 hours.

Tropical Cyclone Zelia will bring strong winds and heavy rain to parts of Western Australia.

A Warning is in effect for the portion of the coast from Broome to Port Hedland.  The Warning includes Wallal Downs and De Grey.

A Watch is in effect for the portion of the coast from Port Hedland to Dampier.  The Watch extends inland to Marble Bar.

Heavy rain is likely to cause floods in some locations.

Flood Watches are in effect for the De Grey River, the Pilbara coastal Rivers, the Fortescue River and parts of the Sandy Desert.

Elsewhere over the South Indian Ocean, Tropical Cyclone Vince continued to move farther away from Rodrigues and Tropical Cyclone Taliah continued to move farther away from the Cocos Islands.

At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Vince was located at latitude 29.5°S and longitude 70.3°E which put the center about 805 miles (1295 km) south-southeast of Port Mathurin, Rodrigues.  Vince was moving toward the south-southeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h). vThe minimum surface pressure was 971 mb.

At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Taliah was located at latitude 16.4°S and longitude 91.5°E which put the center about 435 miles (705 km) southwest of the Cocos Islands.  Taliah was moving toward the south-southwest at 8 m.p.h. (13 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 982 mb.

Tropical Low Develops Near Western Australia

A Tropical Low developed near the coast of Western Australia on Monday.  At 4:00 p.m. EST on Monday the center of the Tropical Low was located at latitude 15.7°S and longitude 120.9°E which put the center about 180 miles (290 km) north-northwest of Broome, Australia.  The Tropical Low was moving toward the southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 997 mb.

The circulation around a Tropical Low near the coast of Western Australia exhibited more organization on Monday.  Thunderstorms organized in bands in the southern and western parts of the Tropical Low.  Bands in the northern and eastern parts of the circulation still consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence that started to pump mass away from the Tropical Low.

The Tropical Low will move through an environment favorable for intensification during the next 24 hours.  The Tropical Low 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 over Australia.  The upper level ridge will produce easterly winds that will blow toward the top of the Tropical Low’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  The Tropical Low is likely to intensify during the next 24 hours.

The Tropical Low will move around the western side of a high pressure system over Australia.  The high pressure system will steer the Tropical Low toward the south-southwest during the next 24 hours.  The Tropical Low will move more toward the south later this week.  On its anticipated track, the Tropical Low will move toward the coast of Western Australia.

The Tropical Low is likely to intensify to a tropical cyclone before it reaches the coast of Western Australia.  It will bring strong winds and locally heavy rain to parts of Western Australia later this week.

A Watch is in effect for the portion of the coast from Cape Leveque to Port Hedland.  The Watch includes Broome, Wallal Downs, and De Grey.

A Flood Watch is in effect for the De Grey River and parts of the Sandy Desert catchments.

Elsewhere over the South Indian Ocean, Tropical Cyclone Vince moved farther away from Rodrigues and Tropical Cyclone Taliah moved farther away from the Cocos Islands.

At 4:00 p.m. EST on Monday the center of Tropical Cyclone Vince was located at latitude 25.4°S and longitude 68.6°E which put the center about 515 miles (835 km) southeast of Port Mathurin, Rodrigues.  Vince was moving toward the south at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 960 mb.

At 4:00 p.m. EST on Monday the center of Tropical Cyclone Taliah was located at latitude 14.2°S and longitude 92.2°E which put the center about 330 miles (530 km) west-southwest of the Cocos Islands.  Taliah was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 992 mb.

Tropical Low Forms Near Western Australia

A Tropical Low formed near the coast of Western Australia on Friday.  At 4:00 p.m. EST on Friday the center of the Tropical Low was located at latitude 19.0°S and longitude 120.0°E which put the center about 100 miles (160 km) northeast of Port Hedland, Australia.  The tropical low was moving toward the west-southwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 995 mb.

A Warning was in effect for the portion of the coast from De Grey to Dampier.  The Warning included Port Hedland and Karratha.

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

A low pressure system over the South Indian Ocean near the coast of Western Australia developed a well defined center of circulation and the Australian Bureau of Meteorology designated the system as a Tropical Low.  A ring of thunderstorms was forming around the center of the Tropical Low.  Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical low.  Bands of showers and thunderstorms were revolving around the center of circulation.

The Tropical Low will move through an environment favorable for the intensification of a tropical cyclone during the next 24 hours.  The Tropical Low will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge northwest of Australia.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  The only factor that will inhibit the intensification of the Tropical Low is the fact that the center of circulation is near the coast of Western Australia.  Much of the southern part of the Tropical Low is over land.  The Tropical Low is likely to intensify to a named tropical cyclone during the next 24 hours.

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

The Tropical Low will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain is likely to cause flash floods in some locations.

Tropical Cyclone Olga Rapidly Intensifies to Equivalent of Cat. 4 Hurricane

Tropical Cyclone Olga rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale during Sunday morning. At 11:00 a.m. EDT on Sunday the center of Tropical Cyclone Olga was located at latitude 15.6°S and longitude 119.1°E which put it about 365 miles (590 km) north of the Port Hedland, Australia. Olga was moving toward the south-southwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 140 m.p.h. (235 km/h) and there were wind gusts to 165 m.p.h. (265 km/h). The minimum surface pressure was 939 mb.

Tropical Cyclone Olga rapidly intensified to the equivalent of a Category 4 hurricane over the South Indian Ocean north of Western Australia during Sunday morning. A small circular eye with a diameter of 10 miles (16 km) was present at the center of Olga’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 Olga. Storms near the core generated strong upper level divergence that pumped mass away from the tropical cyclone. The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Tropical Cyclone Olga was small. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Olga’s circulation. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Olga was 28.3. The Hurricane Size Index (HSI) was 6.1 and the Hurricane Wind Intensity Size Index (HWISI) was 34.4.

Hurricane Olga will move into an environment that will become unfavorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 28°C. An upper level trough over the South Indian Ocean will approach Tropical Cyclone Olga from the west. The trough will produce strong westerly winds that will blow toward the top of Olga’s circulation. Those winds will cause the vertical wind shear to increase. Tropical Cyclone Olga will start to weaken when the wind shear increases. Olga could weaken rapidly because of the small size of its circulation.

Tropical Cyclone Olga will move around the northwestern part of a high pressure system over Australia. The high pressure system will steer Olga toward the southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Olga will move parallel to the coast of Western Australia. Olga is forecast to turn more toward the west-southwest on Monday. Tropical Cyclone Olga is expected to have a minimal impact on Western Australia. Olga will bring gusty winds and large waves to the area around Rowley Shoals.

Tropical Cyclone Olga Rapidly Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Olga rapidly intensified to the equivalent of a major hurricane on Saturday night. At 5:00 a.m. EDT on Sunday the center of Tropical Cyclone Olga was located at latitude 15.0°S and longitude 119.1°E which put it about 405 miles (655 km) north of the Port Hedland, Australia. Olga was moving toward the southwest at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h). The minimum surface pressure was 958 mb.

Tropical Cyclone Olga rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean north of Western Australia on Saturday night. A small circular eye with a diameter of 10 miles (16 km) was present at the center of Olga’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 Olga. Storms near the core generated strong upper level divergence that pumped mass away from the tropical cyclone. The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Tropical Cyclone Olga was small, but it was symmetrical. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Olga’s circulation. Winds to tropical storm force extended out 75 miles (120 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Olga was 20.6. The Hurricane Size Index (HSI) was 7.2 and the Hurricane Wind Intensity Size Index (HWISI) was 27.8.

Hurricane Olga will move into an environment that will become unfavorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 28°C. An upper level trough over the South Indian Ocean will approach Tropical Cyclone Olga from the west. The trough will produce strong westerly winds that will blow toward the top of Olga’s circulation. Those winds will cause the vertical wind shear to increase. Tropical Cyclone Olga could continue to intensify during the next few hours, but Olga will start to weaken when the wind shear increases.

Tropical Cyclone Olga will move around the northwestern part of a high pressure system over Australia. The high pressure system will steer Olga toward the southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Olga will move parallel to the coast of Western Australia. Olga is forecast to turn more toward the west-southwest on Monday. Tropical Cyclone Olga is forecast to have a minimal impact on Western Australia. Olga will bring gusty winds and large waves to the area around Rowley Shoals.

Tropical Cyclone Olga Strengthens to Equivalent of a Hurricane/Typhoon

Tropical Cyclone Olga strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean northwest of Australia on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Olga was located at latitude 14.5°S and longitude 119.6°E which put it about 435 miles (700 km) north of the Port Hedland, Australia. Olga was moving toward the south-southwest at 9 m.p.h. (15 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.

Tropical Cyclone Olga strengthened to the equivalent of a hurricane/typhoon northwest of Australia on Saturday. The inner end of a rainband wrapped around the center of Olga’s circulation. A circular eye with a diameter of 16 miles (26 km) formed at the center of Tropical Cyclone Olga. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center of Olga generated upper level divergence that pumped mass away from the tropical cyclone. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Tropical Cyclone Olga. Winds to tropical storm force extended out 75 miles (120 km) from the center of Olga’s circulation.

Tropical Cyclone Olga will move through an environment favorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 29°C. It will move under the western part of the axis an upper level ridge over northern Australia. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Olga will continue to intensify during the next 24 hours.

Tropical Cyclone Olga will move around the northwestern part of a high pressure system over Australia. The high pressure system will steer Olga slowly toward the southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Olga will parallel to the coast of Western Australia. Olga is forecast to turn more toward the west-southwest on Monday. Tropical Cyclone Olga is forecast to have a minimal impact on Western Australia.