Tag Archives: Rowley Shoals

Tropical Cyclone Olga Weakens

Leave a reply

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

Leave a reply

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

Leave a reply

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 Ilsa Strengthens to Equivalent of Cat. 4 Hurricane

Tropical Cyclone Ilsa strengthened to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Ilsa was located at latitude 18.1°S and longitude 119.2°E which put it about 175 miles (285 km) northwest of Wallal Downs, Australia. Ilsa was moving toward the south-southwest at 7 m.p.h. (11 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 942 mb.

A Tropical Cyclone Warning was in effect for the coast of Western Australia from south of Broome to Whim Creek. The Warning included Port Hedland. The Tropical Cyclone Warning extended inland to include De Grey, Marble Bar, Nullagine, Telfer and Parnngurr.

Tropical Cyclone Ilsa strengthened to the equivalent of a Category 4 hurricane on Wednesday night. A small circular eye was present at the center of Ilsa’s circulation. The 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 Tropical Cyclone Ilsa. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone. The removal of large quantities of mass was causing the surface pressure to continue to decrease.

A weather station at Rowley Shoals measured a sustained wind speed of 95 m.p.h. (83 kt or 154 km/h). The weather station measured a wind gust of 132 m.p.h. (115 kt or 213 km/h). It also measured a sea level pressure of 942.3 mb.

Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Tropical Cyclone Ilsa. Winds to tropical storm force extended out 120 miles (195 km) from the center. The Hurricane Intensity Index (HII) for Tropical Cyclone Ilsa was 25.1. The Hurricane Size Index (HSI) was 13.4 and the Hurricane Wind Intensity Size Index (HWISI) was 38.5. Tropical Cyclone Ilsa was similar in size and intensity to Hurricane Harvey hit Texas in 2017.

Tropical Cyclone Ilsa will move through an environment favorable for intensification during the next 12 hours. Ilsa will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge that extends from northern Australia to the South Indian Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Ilsa could continue to intensify during the next 12 hours.

Tropical Cyclone Ilsa will move around the western end of a high pressure system over western Australia. The high pressure system will steer Ilsa toward the southeast during the next 24 hours. On its anticipated track, the center of Tropical Cyclone Ilsa is likely to make landfall on the coast of Western Australia between Pardoo Roadhouse and Wallal Downs in 12 hours. Ilsa will be the equivalent of a major hurricane when it makes landfall.

Tropical Cyclone Ilsa will bring very strong winds and locally heavy rain to Western Australia between Pardoo Roadhouse and Wallal Downs. The strong winds will be capable of causing regional severe damage. Ilsa could also produce strong winds in De Grey and Telfer when it moves inland. Heavy rain could cause flash floods in some locations. Flood Watches are in effect for the West Kimberley, De Grey River, Sandy Desert, Western Desert, Warburton and Salt Lake Districts. Tropical Cyclone Ilsa could also cause a storm surge of up to 10 to 15 feet (3 to 4.5 meters) along the portion of the coast near where the center makes landfall.