Tag Archives: Courtney

Tropical Cyclone Courtney Equivalent of Cat. 4 Hurricane

Tropical Cyclone Courtney was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale over the South Indian Ocean on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Courtney was located at latitude 19.9°S and longitude 89.1°E which put the center about 715 miles (1150 km) southwest of the Cocos Islands.  Courtney was moving toward the southwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 939 mb.

Tropical Cyclone Courtney strengthened on Saturday.  Courtney was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  A small circular eye was present at the center of Courtney’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 center of Courtney’s circulation.  Storms near the center 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 Courtney was small.  Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Courtney’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Tropical Cyclone Courtney.

The Hurricane Intensity Index (HII) for Tropical Cyclone Courtney was 29.9.  The Hurricane Size Index (HSI) was 10.7 and the Hurricane Wind Intensity Size Index (HWISI) was 40.6.

Tropical Cyclone Courtney will move through an environment that will become unfavorable for intensification during the next 24 hours.  Courtney 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 Courtney’s circulation.  Those winds will cause the vertical wind shear to increase.  Tropical Cyclone Courtney will weaken when the vertical wind shear increases.

Tropical Cyclone Courtney will move around the western end of a high pressure system over the South Indian Ocean.  The high pressure system will steer Courtney toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Courtney will move farther away from the Cocos Islands.

Tropical Cyclone Dianne Brings Wind and Rain to Western Australia

Tropical Cyclone Dianne brought wind and rain to Western Australia on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Dianne was located at latitude 16.6°S and longitude 123.8°E which put the center about 75 miles (120 km) north-northeast of the Derby, Australia.  Dianne was moving toward the south at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 991 mb.

A Warning is in effect for the portion of the coast between Kuri Bay and Derby.

The center of Tropical Cyclone Dianne made landfall on the coast of Western Australia north-northeast of Derby.  Dianne was the equivalent of a tropical storm at the time of landfall.  The circulation around Tropical Cyclone Dianne was small.  Winds to tropical storm force only extended out 65 miles (105 km) from the center of Dianne’s circulation.

Tropical Cyclone Dianne will move around the western end of a high pressure system over northern Australia.  The high pressure system will steer Dianne toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Dianne will move inland over Western Australia during the next 24 hours.

Tropical Cyclone Dianne will bring strong winds and locally heavy rain to parts of Western Australia.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for the Tanami Desert, the Western Desert and the Sandy Desert.

Elsewhere over the South Indian Ocean, Tropical Cyclone Courtney intensified to the equivalent of a major hurricane southwest of the Cocos Islands.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Courtney was located at latitude 17.6°S and longitude 92.5°E which put the center about 445 miles (715 km) southwest of the Cocos Islands.  Courtney was moving toward the west-southwest at 18 m.p.h. (30 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 948 mb.

Tropical Cyclone Dianne Nears Western Australia

Tropical Cyclone Dianne neared the coast of Western Australia on Friday morning.  At 5:00 a.m. EDT on Friday the center of Tropical Cyclone Dianne was located at latitude 15.3°S and longitude 123.6°E which put the center about 140 miles (225 km) north of the Derby, Australia.  Dianne was moving toward the south-southeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 991 mb.

A Warning is in effect for the area between Kuri Bay and Derby.

A Tropical Low strengthened to Tropical Cyclone Dianne near the coast of Western Australia during Thursday night.  More thunderstorms formed near the center of Tropical Cyclone Dianne.  More thunderstorms also formed in bands revolving around the center of Dianne’s circulation.  Storms near the center of Dianne generated more upper level divergence that pumped mass away from the tropical cyclone.  The removal of more mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Dianne was small.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Dianne’s circulation.

Tropical Cyclone Dianne will move through an environment somewhat favorable for intensification during the next few hours.  Dianne will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the northern part of an upper level ridge that extends from over Australia to the South Indian Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of the Tropical Low.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Dianne could intensify during the next few hours.

Tropical Cyclone Dianne will move around the western end of a high pressure system over northern Australia.  The high pressure system will steer Dianne toward the southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Dianne will make landfall on the coast of Western Australia northeast of Derby in a few hours.

Tropical Cyclone Dianne will bring strong winds and locally heavy rain to parts of Western Australia.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for the Tanami Desert, the Western Desert and the Sandy Desert.

Elsewhere over the South Indian Ocean, Tropical Cyclone Courtney passed south of the Cocos Islands.  At 5:00 a.m. EDT on Friday the center of Tropical Cyclone Courtney was located at latitude 16.9°S and longitude 94.9°E which put the center about 330 miles (530 km) south-southwest of the Cocos Islands.  Courtney was moving toward the west at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 972 mb.

Tropical Low Prompts Watch for Western Australia

A risk posed by a Tropical Low prompted the Australian Bureau of Meteorology to issue a Watch for a portion of the coast of Western Australia on Thursday.  At 5:00 a.m. EDT on Thursday the center of the Tropical Low was located at latitude 13.8°S and longitude 121.8°E which put the center about 215 miles (350 km) west-northwest of the Kuri Bay, Australia.  The Tropical Low was moving toward the east-northeast at 5 m.p.h. (7 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.

A Watch is in effect for the portion of the coast of Western Australia from Mitchell Plateau to Beagle Bay.  The Watch includes Derby and Beagle Bay.

A low pressure system over the South Indian Ocean west of Australia exhibited more organization on Thursday morning and the Australian Bureau of Meteorology classified the system as a Tropical Low.  The U.S. Joint Typhoon Warning Center designated the low pressure system as Invest 93S.

The distribution of thunderstorms in the Tropical Low was asymmetrical.  Thunderstorms were occurring in bands in the western side of the Tropical Low.  Bands in the eastern side of the Tropical Low consisted primarily of showers and lower clouds.  Storms near the center of circulation generated upper level divergence that pumped mass away to the west of the Tropical Low.  The removal of mass caused the surface pressure to decrease slowly.

The Tropical Low will move through an environment somewhat favorable for intensification during the next 24 hours.  The Tropical Low will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the northern part of an upper level ridge that extends from over Australia to the South Indian Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of the Tropical Low.  Those winds will cause moderate vertical wind shear.  The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  The Tropical Low could intensify during the next 24 hours.

The Tropical Low will move around the western end of a high pressure system over northern Australia.  The high pressure system will steer the Tropical Low toward the southeast during the next 24 hours.  On its anticipated track, the Tropical Low will make landfall on the coast of Western Australia between Kuri Bay and Derby in 36 hours.

The Tropical Low will bring strong winds and locally heavy rain to parts of Western Australia.  Heavy rain could cause flash floods in some locations.

Elsewhere over the South Indian Ocean, Tropical Cyclone Courtney continued to strengthen south-southeast of the Cocos Islands.  At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Courtney was located at latitude 16.8°S and longitude 99.5°E which put the center about 380 miles (610 km) south-southeast of the Cocos Islands.  Courtney was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 973 mb.

Tropical Cyclone Courtney Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Courtney strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean southeast of the Cocos Islands on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Courtney was located at latitude 17.3°S and longitude 101.7°E which put the center about 505 miles (815 km) southeast of the Cocos Islands.  Courtney was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 980 mb.

Tropical Cyclone Courtney strengthened steadily on Wednesday.  The inner end of a rainband wrapped around the center of Courtney’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Courtney.  Storms near the center of Courtney generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Tropical Cyclone Courtney increased on Wednesday.  Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Courtney’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Tropical Cyclone Courtney.

Tropical Cyclone Courtney will move through an environment somewhat favorable for intensification during the next 24 hours. Courtney will move over water where where the Sea Surface Temperatures are near 28°C.  It will move under the northern part of an upper level ridge that is west of Australia.  The upper level ridge will produce easterly winds that will blow toward the top of Courtney’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Cyclone Courtney is likely to intensify during the next 24 hours.

Tropical Cyclone Courtney will move around the northern side of a high pressure system that is over the South Indian Ocean.  The high pressure system will steer Courtney toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Courtney will pass south of the Cocos Islands later this week.

Tropical Cyclone Courtney Develops Northwest of Australia

Tropical Cyclone Courtney developed over the South Indian Ocean northwest of Australia on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Courtney was located at latitude 17.4°S and longitude 106.3°E which put the center about 585 miles (945 km) northwest of Exmouth, Australia.  Courtney was moving toward the west-southwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 993 mb.

A low pressure system over the South Indian Ocean northwest of Australia strengthened on Tuesday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Courtney.  More thunderstorms formed near the center of Courtney’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Cyclone Courtney.  Storms near the center of Courtney 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 Courtney was small.  Winds to tropical storm force extended out 85 miles (135 km) from the center of Courtney’s circulation.

Tropical Cyclone Courtney will move through an environment somewhat favorable for intensification during the next 24 hours.  Courtney will move over water where where the Sea Surface Temperatures are near 28°C.  It will move under the northern part of an upper level ridge that is west of Australia.  The upper level ridge will produce easterly winds that will blow toward the top of Courtney’s circulation.  Those winds will cause moderate vertical wind shear.  The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Cyclone Courtney is likely to intensify during the next 24 hours.

Tropical Cyclone Courtney will move around the northern side of a high pressure system that is over the South Indian Ocean.  The high pressure system will steer Courtney toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Courtney will pass far to the south of Christmas Islands.  Courtney will pass south of the Cocos Islands later this week.