Category Archives: Australian Region

Tropical Cyclone Robyn Spins Southwest of Cocos Islands

Tropical Cyclone Robyn was spinning over the South Indian Ocean southwest of the Cocos Islands on Thursday.  At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Robyn was located at latitude 16.6°S and longitude 91.2°E which put the center about 485 miles (780 km) southwest of the Cocos Islands.  Robyn was moving toward the south-southeast at 13 m.p.h. (20 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 988 mb.

Tropical Cyclone Robyn strengthened on Thursday as it spun over the South Indian Ocean southwest of the Cocos Islands.  More thunderstorms formed near the center of Robyn’s circulation.  Thunderstorms were occurring in bands revolving around the center of Tropical Cyclone Robyn.  Storms near the center of Robyn generated upper level divergence that pumped mass away to the southeast of the tropical cyclone.

The distribution of winds speeds in Tropical Cyclone Robyn became more symmetrical on Thursday.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Robyn’s circulation.

Tropical Cyclone Robyn will move through an environment that will become unfavorable for intensification during the next 24 hours.  Robyn will move over water where where the Sea Surface Temperatures are near 26°C.  It will move under the western end of an upper level ridge that is west of Australia.  The upper level ridge will produce northerly winds that will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear. The combination of moderate vertical wind shear and marginal Sea Surface Temperatures is likely to cause Tropical Cyclone Robyn to weaken during the next 24 hours.

Tropical Cyclone Robyn will move around the southwestern end of a high pressure system that is west of Australia.  The high pressure system will steer Robyn toward the south-southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Robyn will move farther away from the Cocos Islands.

Tropical Cyclone 03S Forms West of Cocos Islands

Tropical Cyclone 03S formed over the South Indian Ocean west of the Cocos Islands on Wednesday.  At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone 03S was located at latitude 13.1°S and longitude 91.2°E which put the center about 385 miles (620 km) west of the Cocos Islands.  The tropical cyclone was moving toward the south-southwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 995 mb.

A low pressure system over the South Indian Ocean west of the Cocos Islands strengthened on Wednesday and the U.S. Joint Typhoon Warning Center designated the system as Tropical Cyclone 03S.  The distribution of thunderstorms in Tropical Cyclone 03S was asymmetrical.  Thunderstorms were occurring in bands in the western side of the tropical cyclone’s circulation.  Bands in the eastern side of the circulation consisted primarily of showers and lower clouds.  Storms west of the center of circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone.

The distribution of wind speeds in Tropical Cyclone 03S was also asymmetrical.  Winds to tropical storm force extended out 140 miles (225 km) in the southern side of the tropical cyclone.  Winds to tropical storm force only extended out 70 miles (110 km) in the northern side of Tropical Cyclone 03S.

Tropical Cyclone 03S will move through an environment somewhat favorable for intensification during the next 24 hours.  The tropical cyclone will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the western end of an upper level ridge that is west of Australia.  The upper level ridge will produce northerly winds that will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification.  Tropical Cyclone 03S could strengthen during the next 24 hours if the upper level winds do not get any stronger.

Tropical Cyclone 03S will move around the western end of a high pressure system that is west of Australia.  The high pressure system will steer the tropical cyclone toward the south-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone 03S will move farther away from the Cocos Islands.

Tropical Cyclone Paul Weakens

Tropical Cyclone Paul weakened over the Coral Sea on Thursday night. At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Paul was located at latitude 15.2°S and longitude 156.5°E which put it about 325 miles (525 km) southeast of the Tagula Island. Paul was moving toward the east at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1001 mb.

Tropical Cyclone Paul strengthened earlier on Thursday when it was in a more favorable environment. Then an upper level trough near the east coast of Australia began to produce strong west-northwesterly winds that blew across the top of Paul’s circulation. Those winds caused the vertical wind shear to increase. The stronger vertical wind shear blew the tops off of many of the thunderstorms in Tropical Cyclone Paul. A few thunderstorms were still occurring in bands in the southeastern part of Paul’s circulation. Bands in the other parts of Tropical Cyclone Paul consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 40 miles (65 km) from the center of Paul.

Tropical Cyclone Paul will move through an environment unfavorable for intensification during the next 24 hours. Paul will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough near eastern Australia will continue to produce strong west-northwesterly winds that will blow across the top of Paul’s circulation. Those winds will cause strong vertical wind shear. The strong wind shear will cause Paul to continue to weaken.

Tropical Cyclone Paul will be steered by the winds in the lower levels of the atmosphere because of the strong vertical wind shear. Paul will move around the northern side of high pressure system over the Southwest Pacific Ocean and eastern Australia. The high pressure system will steer Paul toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Cyclone Paul will weaken over the Coral Sea.

Tropical Cyclone Paul Forms over Coral Sea

Tropical Cyclone Paul formed over the Coral Sea on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Paul was located at latitude 13.8°S and longitude 154.3°E which put it about 150 miles (240 km) south-southeast of the Tagula Island. Paul was moving toward the south-southeast at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1000 mb.

A low pressure system over the Coral Sea southeast of New Guinea strengthened on Wednesday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Paul. More thunderstorms formed near the center of Tropical Cyclone Paul. The inner end of a rainband wrapped around the northern side of the center of Paul’s circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone. Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Paul. The circulation around Paul was small. Winds to tropical storm force extended out 30 miles (50 km) from the center of Paul’s circulation.

Tropical Cyclone Paul will move through an environment favorable for intensification during the next 24 hours. Paul will move over water where the Sea Surface Temperatures are near 29°C. An upper level trough over eastern Australia will produce west-northwesterly winds that will blow toward the top of Paul’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Cyclone Paul could intensify during the next 24 hours despite the wind shear. The vertical wind shear is forecast to increase on Friday. Paul will start to weaken when the wind shear increases.

Tropical Cyclone Paul will be in an area where the steering winds are weak during the next 24 hours. Tropical Cyclone Paul will not move much during the next day or so. A high pressure system over the Southwest Pacific Ocean and eastern Australia is likely to start to steer Paul toward the west on Friday. On its anticipated track, Tropical Cyclone Paul will eventually start to move toward the northern Cape York Peninsula.

Elsewhere, a weakening Tropical Cyclone Olga was passing near Exmouth, Australia. At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Olga was located at latitude 21.4°S and longitude 114.3°E which put it about 85 miles (135 km) north-northeast of the Exmouth, Australia. Olga was moving toward the southwest at 12 m.p.h. (19 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 1007 mb. A weather station on Barrow Island reported a sustained wind speed of 37 m.p.h. (59 km/h) and a wind gust of 45 m.p.h. (72 km/h).

Tropical Cyclone Olga Continues to Weaken

Tropical Cyclone Olga continued to weaken on Tuesday as it moved over the South Indian Ocean north of Western Australia. At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Olga was located at latitude 19.3°S and longitude 115.8°E which put it about 265 miles (435 km) north-northeast of the Exmouth, Australia. Olga was moving toward the south-southwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1003 mb.

An upper level trough over the South Indian Ocean west of Australia continued to produce strong northwesterly winds that blew toward the top of Tropical Cyclone Olga’s circulation. Those winds caused strong vertical wind shear. The strong upper level winds blew the tops off of most of the thunderstorms in Tropical Cyclone Olga. There were still a few thunderstorms in bands in the southeastern periphery of Olga’s circulation. Bands in the other parts of Tropical Cyclone Olga consisted primarily of showers and lower clouds.

The strong vertical wind shear also caused the pattern of wind speeds around Tropical Cyclone Olga to be asymmetrical. Winds to tropical storm force extended out 100 miles (160 km) in the southern half of Olga’s circulation. Winds to tropical storm force only extended out 35 miles (55 km) in the northern half of Tropical Cyclone Olga.

Tropical Cyclone Olga will move through an environment that will be unfavorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 28°C. However, the upper level trough west of Australia will continue to cause strong vertical wind shear. The strong wind shear will cause Tropical Cyclone Olga to continue to weaken.

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 be north of Exmouth in 24 hours.

Tropical Cyclone Olga was already bringing gusty winds to the area around Barrow Island. A weather station on Barrow Island reported a sustained wind speed of 36 m.p.h. (58 km/h) and a wind gust of 46 m.p.h. (74 km/h).

Tropical Cyclone Olga Weakens

Tropical Cyclone Olga weakened over the South Indian Ocean north of Western Australia on Monday. At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Olga was located at latitude 17.5°S and longitude 117.2°E which put it about 250 miles (400 km) north of the Karratha, Australia. Olga was moving toward the 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 994 mb.

Strong vertical wind shear caused Tropical Cyclone Olga to weaken steadily on Monday. An upper level trough over the South Indian Ocean west of Australia produced strong northwesterly winds that blew toward the top of Olga’s circulation. Those winds caused strong vertical wind shear. The wind shear caused the distribution of thunderstorms in Tropical Cyclone Olga to become asymmetrical. Thunderstorms were occurring in bands in the southeastern part of Olga’s circulation. Bands in the other parts of Tropical Cyclone Olga consisted primarily of showers and lower clouds.

The strong vertical wind shear also caused the pattern of wind speeds around Tropical Cyclone Olga to become asymmetrical. Winds to tropical storm force extended out 145 miles (235 km) in the southern half of Olga’s circulation. Winds to tropical storm force only extended out 75 miles in the northern half of Tropical Cyclone Olga.

Tropical Cyclone Olga will move through an environment that will be unfavorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 28°C. However, the upper level trough west of Australia will continue to cause strong vertical wind shear. The strong wind shear will cause Tropical Cyclone Olga to continue to weaken.

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 gradually move closer to the coast of Western Australia.

Tropical Cyclone Olga brought strong gusty winds to the area around Rowley Shoals. A weather station on Rowley Shoals reported a sustained wind speed of 48 m.p.h. (78 km/h) and a wind gust of 61 m.p.h. (98 km/h). Olga could bring strong gusty winds to Barrow Island during the next 24 hours.

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.

Tropical Cyclone Olga Forms Northwest of Australia

Tropical Cyclone Olga formed northwest of Australia on Friday night. At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Olga was located at latitude 12.95°S and longitude 120.1°E which put it about 520 miles (840 km) north of the Port Hedland, Australia. Olga was moving toward the south at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 998 mb.

A low pressure system over the South Indian Ocean between Indonesia and Australia strengthened on Friday night and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Olga. The circulation around Tropical Cyclone Olga exhibited more organization on Friday night. A band of thunderstorms wrapped around the center of Olga’s circulation. Other 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 tropical storm force extended out 60 miles (95 km) from the center of Tropical Cyclone Olga.

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 through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Olga will intensify during the next 24 hours. Olga could strengthen to the equivalent of a hurricane/typhoon.

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 south during the next 24 hours. On its anticipated track, Tropical Cyclone Olga will move a little closer to Western Australia. Olga is forecast to turn more toward the west later in the weekend. Tropical Cyclone Olga is forecast to have a minimal impact on Western Australia.