Tag Archives: Cocos Islands

Tropical Cyclone Herman Strengthens Northwest of Australia

Tropical Cyclone Herman strengthened over the South Indian Ocean northwest of Australia during Wednesday night. At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Herman was located at latitude 15.5°S and longitude 105.1°E which put it about 570 miles (920 km) east-southeast of Cocos Islands. Herman was moving toward the 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 985 mb.

Tropical Cyclone Herman strengthened over the South Indian Ocean northwest of Australia during the past 24 hours. The inner end of a rainband wrapped completely around the center of Herman’s circulation. A small circular eye formed at the center of circulation. A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center generated upper level divergence that pumped mass away to the southeast of the tropical cyclone. Winds to tropical storm force extended out 65 miles (105 km) from the center of Herman’s circulation.

Tropical Cyclone Herman will move through an environment that will become unfavorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. However, an upper level trough will approach Tropical Cyclone Herman from the west. The upper level trough will produce northwesterly winds that will get stronger during the next 24 hours. Those stronger winds will blow toward the top of Herman’s circulation and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken.

The upper level trough will steer Tropical Cyclone Herman toward the southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move farther away from Cocos Islands. When the stronger vertical wind shear causes Herman to weaken, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the end of the week and the weekend.

Tropical Cyclone Herman Forms Northwest of Australia

Tropical Cyclone Herman formed over the South Indian Ocean northwest of Australia on Wednesday morning. At 5:00 a.m. EDT on Wednesday the center of Tropical Cyclone Herman was located at latitude 13.9°S and longitude 101.5°E which put it about 300 miles (480 km) east-southeast of Cocos Islands. Herman was moving toward the southwest at 12 m.p.h. (19 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 997 mb.

An area of low pressure over the South Indian Ocean east-southeast of Cocos Islands strengthened on Wednesday morning and the the Australian Bureau of Meteorology designated the system as Tropical Cyclone Herman. The inner end of a rainband wrapped around the western side of the center of Herman’s circulation. The strongest winds were occurring in the part of the band west of the center. Other bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 160 miles (260 km) from the center of Herman’s circulation.

Tropical Cyclone Herman will move through an environment favorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western end of an upper level ridge over the eastern part of the South Indian Ocean. The ridge will produce northerly winds that will blow toward the top of Herman’s circulation. Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification. Tropical Cyclone Herman is likely to strengthen during the next 24 hours. An upper level trough will approach Herman from the west on Thursday. The trough will cause the upper level winds to get stronger and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken.

Tropical Cyclone Herman will move around the southwestern part of a high pressure system over the eastern South Indian Ocean. The high pressure system will steer Herman toward the southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move away from Cocos Islands. When Herman weakens later this week, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the end of the week and the weekend.

Tropical Cyclone Freddy Passes South of the Cocos Islands

Tropical Cyclone Freddy passed south of the Cocos Islands on Sunday night. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Freddy was located at latitude 15.4°S and longitude 94.1°E which put it about 275 miles (445 km) south-southwest of Cocos Islands. Freddy was moving toward the west at 14 m.p.h. (22 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 964 mb.

Tropical Cyclone Freddy weakened a little as it passed south of the Cocos Islands on Sunday night. Freddy was moving under the northern part of an upper level ridge over the Southeast Indian Ocean. The ridge produced stronger easterly winds that blew toward the top of Freddy’s circulation during Sunday night. Those winds caused more vertical wind shear and the shear caused Tropical Cyclone Freddy to weaken a little. The wind shear also caused the distribution of thunderstorms in Freddy’s circulation to become more asymmetrical. Many of the thunderstorms were occurring in bands in the western half of Tropical Cyclone Freddy. Some of the bands in the eastern side of Freddy consisted primarily of showers and lower clouds. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Tropical Cyclone Freddy. Winds to tropical storm force extended out 110 miles (175 km) from the center of circulation.

Tropical Cyclone Freddy will move through an environment that will be unfavorable for intensification during the next 24 hours. Freddy will move over over water where the Sea Surface Temperatures are near 27˚C. However, the upper level ridge over the Southeast Indian Ocean will continue to cause moderate vertical wind shear during the next 24 hours. The wind shear is likely to cause Tropical Cyclone Freddy to weaken during the next 24 hours. Freddy could move into a region were the upper level winds are weaker later this week.

Tropical Cyclone Freddy will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Freddy toward the west during the next few days. On its anticipated track, Tropical Cyclone Freddy will move farther away from the Cocos Islands. Freddy could be south of Diego Garcia by the end of the week.

Elsewhere over the South Indian Ocean, Tropical Cyclone Dingani was passing east of Rodrigues. At 4:00 a.m. EST on Monday the center of Tropical Cyclone Dingani was located at latitude 19.2°S and longitude 73.2°E which put it about 660 miles (1060 km) east of Rodrigues. Dingani was moving toward the southwest at 8 m.p.h. (13 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 969 mb.

Tropical Cyclone Dingani Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Dingani strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean on Saturday night. At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Dingani was located at latitude 17.0°S and longitude 75.2°E which put it about 810 miles (1310 km) east-northeast of Rodrigues. Dingani was moving toward the west-southwest at 12 m.p.h. (19 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 981 mb.

Tropical Cyclone Dingani strengthened to the equivalent of a hurricane/typhoon on Saturday night. A circular eye with a diameter of 17 miles (28 km) developed at the center of Dingani’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 Dingani. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Dingani. Winds to tropical storm force extended out 110 miles (175 km) from the center of circulation.

Tropical Cyclone Dingani will move through an environment favorable for intensification during the next 24 hours. Dingani will move over over water where the Sea Surface Temperatures are near 27˚C. It will move under the western part of the axis of an upper level ridge over the South Indian Ocean. The upper level winds are weak near the axis of the ridge. Tropical Cyclone Dingani is likely to intensify during the next 24 hours. Dingani could intensify rapidly at times, since it now has a well developed inner core with an eye and an eyewall.

Tropical Cyclone Dingani will move around the northwestern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Dingani toward the southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Dingani could pass east of Rodrigues early next week.

Elsewhere over the South Indian Ocean, Tropical Cyclone Freddy was southeast of Cocos Islands. Freddy was the equivalent of a major hurricane. At 10:00 a.m. EST on Sunday the center of Tropical Cyclone Freddy was located at latitude 15.1°S and longitude 98.3°E which put it about 240 miles (390 km) southeast of Cocos Islands. Freddy was moving toward the west at 14 m.p.h. (22 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. (230 km/h). The minimum surface pressure was 954 mb.

Tropical Cyclone Freddy Rapidly Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Freddy rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean east-southeast of Cocos Islands on Saturday morning. At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Freddy was located at latitude 14.9°S and longitude 102.5°E which put it about 450 miles (720 km) east-southeast of Cocos Islands. Freddy was moving toward the west at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 949 mb.

Tropical Cyclone Freddy rapidly intensified to the equivalent of a major hurricane on Saturday morning. A small circular eye with a diameter of 12 miles (19 km) formed at the center of Freddy’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds occurred in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Freddy. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Freddy was small. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Freddy. Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Freddy was 22.1. The Hurricane Size Index (HSI) was 11.4 and the Hurricane Wind Intensity Size Index (HWISI) was 33.5.

Tropical Cyclone Freddy will move through an environment favorable for intensification during the next 24 hours. Freddy will move over over water where the Sea Surface Temperatures are near 28˚C. It will move under the northern side of an upper level ridge over the Southeast Indian Ocean. The upper level ridge will produce easterly winds that will blow toward the top of Freddy’s circulation. The winds in the lower levels of the atmosphere will also blow from the east. So, there will be little vertical wind shear. Tropical Cyclone Freddy could continue to intensify rapidly during the next few hours. Since the circulation around Freddy is small, the inner end of a rainband could wrap around the existing eye and eyewall. If concentric eyewalls form, then an eyewall replacement cycle could cause Tropical Cyclone to weaken during the weekend.

Tropical Cyclone Freddy will move around the northern side of a high pressure system over the South Indian Ocean. The high pressure system will steer Freddy toward the west during the next several days. On its anticipated track, the center of Tropical Cyclone Freddy could be south of Cocos Islands in 36 hours. The core of Freddy and the strongest winds will pass south of Cocos Islands. Bands on the northern edge of Freddy’s circulation could bring gusty winds and locally heavy rain to the Cocos Islands.

Elsewhere over the South Indian Ocean, Tropical Cyclone Dingani moved south-southeast of Diego Garcia. At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Dingani was located at latitude 15.6°S and longitude 77.8°E which put it about 740 miles (1195 km) south-southeast of Diego Garcia. Dingani was moving toward the west at 14 m.p.h. (22 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 Freddy Develops Rapidly North of Western Australia

Tropical Cyclone Freddy developed rapidly over the South Indian Ocean north of Western Australia on Monday morning. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Freddy was located at latitude 12.8°S and longitude 118.4°E which put it about 440 miles (710 km) northwest of Broome, Australia. Freddy was moving toward the southwest at 5 m.p.h. (8 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 992 mb.

The circulation around a low pressure system over the South Indian Ocean north of Western Australia strengthened rapidly on Monday morning and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Freddy. The inner end of a rainband wrapped around the southern and western sides of the center of Freddy’s circulation. Other bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Freddy. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical cyclone. The circulation around Tropical Cyclone Freddy was small. Winds to tropical storm force extended out 70 miles (110 km) from the center of Freddy.

Tropical Cyclone Freddy will move through an environment favorable for intensification during the next 36 hours. Freddy will move over over water where the Sea Surface Temperatures are near 29˚C. It will move under the axis of an upper level ridge over 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 Freddy will intensify during the next 36 hours and it could strengthen rapidly at times. Freddy is likely to intensify to the equivalent of a hurricane/typhoon during the next 36 hours. It could strengthen to the equivalent of a major hurricane later this week.

Tropical Cyclone Freddy will move around the northwestern part of a high pressure system over Western Australia. The high pressure system will steer Freddy toward the west-southwest during the next 36 hours. On its anticipated track, Tropical Cyclone Freddy will stay north of Western Australia.

Elsewhere over the South Indian Ocean, a Tropical Low (also designated as Invest 94S) was east of Cocos Islands. At 10:00 a.m. EST on Monday the center of the Tropical Low was located at latitude 12.5°S and longitude 99.9°E which put it about 210 miles (335 km) east of Cocos Islands. The Tropical Low was moving toward the southeast 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 998 mb. The Tropical Low is forecast to turn toward the southwest and to strengthen to a tropical cyclone later this week.

Tropical Cyclone Darian Rapidly Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Darian rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean west of Cocos Islands on Monday. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Darian was located at latitude 12.8°S and longitude 93.5°E which put it about 230 miles (370 km) west of Cocos Islands. Darian was moving toward the south-southeast at 5 m.p.h. (8 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). The minimum surface pressure was 971 mb.

Tropical Cyclone Darian rapidly intensified to the equivalent of a hurricane/typhoon during the past 24 hours. The inner end of a rainband wrapped around the center of Darian’s circulation. An elliptical eye formed at the center of Tropical Cyclone Darian. A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Darian’s circulation. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone in all directions. Winds to hurricane/typhoon force extended out 40 miles (65 km/h) from the center of Tropical Cyclone Darian. Winds to tropical storm force extended out 125 miles (200 km) from the center.

Tropical Cyclone Darian will move through an environment favorable for intensification during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian is likely to intensify during the next 24 hours.

Tropical Cyclone Darian will move around the southwestern part of a high pressure system centered north of Australia. The high pressure system will steer Darian slowly toward the south during the next 24 hours. On its anticipated track Tropical Cyclone Darian will remain southwest of Cocos Islands. A subtropical high pressure system over the South Indian Ocean will steer Darian toward the west later this week.

Tropical Cyclone Darian Forms West of Cocos Islands

Tropical Cyclone Darian formed over the South Indian Ocean west of Cocos Islands on Sunday. At 7:00 a.m. EST on Sunday the center of Tropical Cyclone Darian was located at latitude 11.9°S and longitude 92.8°E which put it about 270 miles (440 km) west of Cocos Islands. Darian was moving toward the southwest at 3 m.p.h. (5 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 993 mb.

The circulation around a low pressure system over the South Indian Ocean west of Cocos Islands strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Darian. The inner end of a rainband wrapped around the southern and western sides of the center of Darian’s circulation. Other bands of showers and thunderstorms were revolving around around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 100 miles (160 km) from the center of Darian.

Tropical Cyclone Darian will move through an environment favorable for intensification during the next 36 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian will intensify during the next 36 hours. Darian could strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Darian will move around the southwestern part of a high pressure system centered north of Australia. The high pressure system will steer Darian slowly toward the southeast during the next 36 hours. On its anticipated track Tropical Cyclone Darian will pass southwest of Cocos Islands.

Tropical Cyclone Mangga Develops Northwest of Cocos Islands

Tropical Cyclone Mangga developed over the South Indian Ocean northwest of the Cocos Islands on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Mangaa was located at latitude 9.4°S and longitude 93.1°E which put it about 320 miles (515 km) northwest of Cocos Island.  Mangga was moving toward the south-southeast at 7 m.p.h. (12 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 996 mb.

The Australian Bureau of Meteorology issued a Warning for the Cocos Islands.

Tropical Cyclone Mangga developed within a trough of low pressure that extended from southwest of Indonesia to western Australia.  The trough had persisted for several days and a center of low pressure gradually formed northwest of the Cocos Islands during the past 24 hours.  The Australian Bureau of Meteorology designated the system as Tropical Cyclone Mangga on Thursday.

The circulation around Tropical Cyclone Mangga was still in the process of organizing.  The strongest thunderstorms were in a band on the western side of the circulation.  Bands on the eastern side of the circulation consisted primarily of showers and lower clouds.  More thunderstorms began to develop near the center of circulation on Thursday.  Storms developing near the center started to generate upper level divergence which was pumping mass away to the west of the tropical cyclone.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Mangga.

Tropical Cyclone Mangga will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Mannga will move over water where the Sea Surface temperature is near 27°C.  It will move under the northwestern part of an upper level ridge centered over Indonesia.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear may be the reason why the bands on the eastern side of Tropical Cyclone Mangga are weaker.  The shear will also inhibit intensification, but it will probably not be strong enough to prevent Manga from strengthening during the next 24 hours.

Tropical Cyclone Mangga will move around the western end of a high pressure system centered north of Australia.  The high will steer Mangga toward the southeast during the next few days.  On its anticipated track Tropical Cyclone Mangga will pass near the Cocos Islands in about 24 hours.  Manga will bring gusty winds and locally heavy rain to those islands.

Tropical Cyclone Kate Intensfies Rapidly over Southeastern Indian Ocean

Favorable oceanic and atmospheric conditions allowed Tropical Cyclone Kate to intensify very rapidly on Friday.  The maximum sustained wind speed increased from 50 m.p.h. to 120 m.p.h. during a 24 hour period.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Kate was located at latitude 12.9°S and longitude 93.8°E which put it about 215 miles west-southwest of the Cocos Islands and about 2450 miles west of Darwin, Australia.  Kate was moving toward the southwest at 5 m.p.h., which was taking it away from the Cocos Islands.  The maximum sustained wind speed was 120 m.p.h. which made Kate the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale and it was estimated that there were gusts to 150 m.p.h.

Although there were upper level winds blowing from the east, which created some wind shear over Kate, it was able to develop strong upper level outflow which produced rapid intensification.  Some satellite imagery shows that the wind shear is causing the strongest thunderstorms to be on the western side of the center of circulation.  Recent visible and infrared satellite imagery show evidence of an circular eye developing.  Some further intensification is possible during the next 24 hours as long as the upper level outflow is able to pump out sufficient mass.  Eventually, as Kate moves toward higher latitudes the wind shear will increase and the Sea Surface Temperatures will decrease.  The more hostile environment will weaken the tropical cyclone and the weakening could be almost as rapid as the intensification was.

Kate is expected to continue to be steered in a generally southwesterly direction in the short term by a subtropical ridge.  As it moves farther south, it will begin to be affected by westerly midlatitude flow and it will start to recurve more toward the south.  Kate passed over the Cocos Islands earlier this week as a tropical storm.  It is expected to dissipate over the Indian Ocean and not affect any other land areas as a tropical cyclone.