Tag Archives: Tropical Cyclone Bianca

Tropical Cyclone Bianca Weakens Rapidly

Tropical Cyclone Bianca weakened rapidly over the South Indian Ocean west of Australia on Wednesday.  At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Bianca was located at latitude 25.7°S and longitude 102.7°E which put the center about 730 miles (1175 km) west of Carnarvon, Australia.  Bianca was moving toward the south-southeast at 7 m.p.h. (11 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 999 mb.

Tropical Cyclone Bianca weakened rapidly over the South Indian Ocean west of Australia on Wednesday.  An upper level trough west of Australia produced strong northwesterly winds that blew across the top of Tropical Cyclone Bianca.  Those winds caused strong vertical wind shear.  The vertical wind shear blew the upper part of Bianca’s circulation to the southeast of the circulation in the lower levels.

The circulation of Tropical Cyclone Bianca consisted of bands of showers and lower clouds that were revolving around the low level center of circulation.  Strong vertical wind shear was blowing the tops off of clouds that rose higher into the atmosphere.

The circulation around Tropical Cyclone Bianca was small.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Bianca’s circulation.

Tropical Cyclone Bianca will move through an environment that will be unfavorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 23°C.  It will move under the eastern side of an upper level trough over the South Indian Ocean.  The upper level trough will continue to produce strong northwesterly winds that will blow across the top of Bianca’s circulation.  Those winds will cause strong vertical wind shear.  Cooler water and strong vertical wind shear will cause Tropical Cyclone Bianca to continue to weaken during the next 24 hours.

Since the circulation around Tropical Cyclone Bianca exists only in the lower levels of the atmosphere, Bianca will be steered by the weather features near the surface.  Bianca will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will move farther away from Western Australia.

Tropical Cyclone Bianca Strengthens to Equivalent of Major Hurricane

Tropical Cyclone Bianca strengthened to the equivalent of a major hurricane on Monday night.  At 4:00 a.m. EST on Tuesday the center of Tropical Cyclone Bianca was located at latitude 22.3°S and longitude 102.0°E which put the center about 765 miles (1235 km) west of the Exmouth, Australia.  Bianca was moving toward the south-southwest at 11 m.p.h. (17 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 962 mb.

Tropical Cyclone Bianca strengthened to the equivalent of a major hurricane over the South Indian Ocean west of Australia on Monday night.  A circular eye with a diameter of 20 miles (32 km) was at the center of Bianca’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 revolved around the center of Bianca’s circulation.  Storms near the center of Bianca generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Bianca was small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Bianca’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Bianca.

The Hurricane Intensity Index (HII) for Tropical Cyclone Bianca was 20.6.  The Hurricane Size Index (HSI) was 9.3 and the Hurricane Wind Intensity Size Index (HWISI) was 29.9.

Tropical Cyclone Bianca will move into an environment that will become unfavorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 26°C.  It will move under the eastern side of an upper level trough over the South Indian Ocean.  The upper level trough will produce northwesterly winds that will blow toward the top of Bianca’s circulation.  Those winds will cause the vertical wind shear to increase.  Tropical Cyclone Bianca will weaken when the vertical wind shear increases.

Tropical Cyclone Bianca will move around the western part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will move parallel to the coast of Western Australia.

Tropical Cyclone Bianca Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Bianca strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean on Sunday night.  At 4:00 a.m. EST on Monday the center of Tropical Cyclone Bianca was located at latitude 19.3°S and longitude 103.3°E which put the center about 645 miles (1040 km) southeast of the Cocos Islands.  Bianca was moving toward the southwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 985 mb.

Tropical Cyclone Bianca rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean southeast of the Cocos Islands during Sunday night.  The inner end of a rainband wrapped around the center of Bianca’s circulation.  A circular eye formed at the center of Tropical Cyclone Bianca.  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 revolved around the center of Bianca’s circulation.  Storms near the center of Bianca 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 Bianca was small.  Winds to hurricane/typhoon force extended out 20 miles (3o km) from the center of Bianca’s circulation.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Tropical Cyclone Bianca.

Tropical Cyclone Bianca will move through an environment favorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level ridge over the South Indian Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Bianca is likely to continue to intensify during the next 24 hours.

Tropical Cyclone Bianca will move around the northwestern part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will remain far to the southeast of the Cocos Islands.

Tropical Cyclone Alfred Forms over the Coral Sea

Tropical Cyclone Alfred formed over the Coral Sea on Sunday.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Alfred was located at latitude 14.3°S and longitude 153.7°E which put the center about 560 miles (900 km) east-northeast of Cairns, Australia.  Alfred was moving toward the east at 8 m.p.h. (13 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 990 mb.

A low pressure system over the Coral Sea strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Alfred.  The circulation around Tropical Cyclone Alfred exhibited more organization on Sunday.  More thunderstorms formed near the center of Alfred’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Cyclone Alfred.  Storms near the center of Alfred 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 Alfred was fairly large.  Winds to tropical storm force extended out 180 miles (290 km) from the center of Alfred’s circulation.

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

Tropical Cyclone Alfred will move around the southern side of a high pressure system that is near the Equator.  The high pressure system will steer Alfred toward the east during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move farther away from Australia.  Alfred is like to start to move toward the south early next week.

Elsewhere, Tropical Cyclone Bianca formed over the South Indian Ocean northwest of Australia.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Bianca was located at latitude 17.0°S and longitude 106.9°E which put the center about 590 miles (950 km) northwest of Exmouth, Australia.  Bianca was moving toward the west-southwest at 15 m.p.h. (24 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.