Tag Archives: SH27

Tropical Cyclone Mangga Brings Wind and Rain to Cocos Island

Tropical Cyclone Mangga brought wind and rain to Cocos Island on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Mangga was located at latitude 16.3°S and longitude 97.6°E which put it about 270 miles (435 km) south of Cocos Island.  Mangga was moving toward the southeast at 21 m.p.h. (34 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 center of Tropical Cyclone Mangga passed southwest of Cocos Island on Friday.  The circulation around Mangga was fairly large.  Winds to tropical storm force extended out 150 miles (240 km) to the northeast of the center of circulation.  A weather station on Cocos Island reported a sustained wind speed of 27 m.p.h. (43 km/h) and a wind gust of 38 m.p.h. (61 km/h).  The station measured 1.25 inches (32 mm) of rain during the passage of Tropical Cyclone Mangga.

The circulation around Tropical Cyclone Mangga did not appear to be well organized.  There were not a lot of thunderstorms near the center or circulation.  Bands near the center consisted primarily of showers and lower clouds.  Thunderstorms were occurring to the southeast of the low level center of circulation.  The thunderstorms appeared to be associated with a circulation in the middle and upper troposphere.  Those thunderstorms were generating upper level divergence which was pumping mass away to the southeast of Tropical Cyclone Mangga.

Tropical Cyclone Mangga will move through an environment only marginally favorable for intensification.  Mangga will move over water where the Sea Surface Temperature is near 27°C.  However, an upper level ridge northwest of Australia and an upper level trough west of Australia will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause strong vertical wind shear.  The shear is likely to be strong enough to prevent intensification of the current low level center of Tropical Cyclone Mangga.  It is possible that the circulation in the middle and upper troposphere could cause a new low level center to form.  If a new center forms where the thunderstorms and upper level divergence are occurring, then some intensification might be possible.

Tropical Cyclone Mangga will move around the southwestern part of a high pressure system centered over Australia.  The high will steer Mangga quickly toward the southeast.  On its anticipated track the center of Tropical Cyclone Mangga could reach the coast of Western Australia in less than 36 hours.  Mangga could produce winds to tropical storm force along the coast of Western Australia.

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.

Weaker Tropical Cyclone Ann Nears Northern Queensland

A weaker Tropical Cyclone Ann neared northern Queensland on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Ann was located at latitude 14.4°S and longitude 148.4°E which put it about 230 miles (370 km) east-northeast of Cooktown, Australia.  Ann was moving toward the west-northwest at 14 m.p.h. (22km/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 996 mb.  The Australian Bureau of Meteorology issued a Tropical Cyclone Warning that extended from Lockhart River to Cooktown including Coen and Lizard Island.

The circulation around Tropical Cyclone Ann weakened on Monday because of a drier, more stable environment and more vertical wind shear.  Low level convergence pulled drier, more stable air closer to the center of Tropical Cyclone Ann.  The drier, more stable air caused many of the stronger thunderstorms to weaken.  Despite the drier, more stable environment stronger thunderstorms redeveloped south of the center of circulation late on Monday.  Tropical Cyclone Ann was moving near the northwestern portion of an upper level ridge.  The ridge produced easterly winds which caused moderate vertical wind shear.  The wind shear also contributed to the weakening of storms in the northern half of the circulation.

Tropical Cyclone Ann continued to have a distinct low level center of circulation despite the less favorable environment.  However, the wind field exhibited a more asymmetric structure.  The strongest winds were occurring in an area of thunderstorms south of the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center in the southern half of the circulation.  Winds to tropical storm force only extended out about 50 miles (80 km) from the center in the northern half of the circulation.

Tropical Cyclone Ann will continue to move through a less favorable environment during the next 24 hours.  Ann will move over water in the Coral Sea where the Sea Surface Temperature is near 27.5°C.  It will continue to move through a region where there is drier, more stable air and the upper level ridge will continue to cause moderate vertical wind shear.  The drier, more stable air and moderate vertical wind shear will prevent significant intensification.  Tropical Cyclone Ann could maintain its intensity during the next 12 hours, but it may weaken when it approaches the coast of the Cape York Peninsula.

Tropical Cyclone Ann will move north of a ridge which will steer Ann toward the west-northwest.  On its anticipated track Tropical Cyclone Ann will make landfall on the Cape York Peninsula in northern Queensland in about 24 hours.  Ann will bring some gusty winds, but the greatest risk will be locally heavy rain.

Tropical Cyclone Ann Strengthens Over Coral Sea

Tropical Cyclone Ann strengthened over the Coral Sea on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Ann was located at latitude 15.4°S and longitude 153.6°E which put it about 565 miles (910 km) east of Cairns, Australia.  Ann was moving toward the west-northwest at 15 m.p.h. (24 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 987 mb.

The circulation around Tropical Cyclone Ann exhibited greater organization on Sunday.  There were indications on satellite images that a cloud filled eye might be trying to form at the center of circulation.  A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Ann.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Ann will be moving through an environment that contains factors favorable for intensification and a factor that will inhibit potential intensification.  Ann will move over water where the Sea Surface Temperature is near 28°C.  So, there will be sufficient energy in the upper ocean to support intensification.  Tropical Cyclone Ann will move north of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Ann is surrounded by drier more stable air and the drier air is the factor that will inhibit intensification.  So far, the circulation around Ann has kept the drier air outside the tropical cyclone.  If the drier air remains outside the circulation, then Tropical Cyclone Ann would have a chance to strengthen.  However, if the drier air gets pulled into the circulation, then Ann will weaken.  The higher probability is that Tropical Cyclone Ann could maintain its intensity or weaken slowly during the next day or two depending on what happens to the drier air.

Tropical Cyclone Ann will move north of an area of high pressure, which will steer the tropical cyclone toward the west-northwest.  On its anticipated track Ann will approach the Cape York Peninsula north of Coen in less than 48 hours.  Tropical Cyclone Ann could bring gusty winds and locally heavy rain to northern Queensland.

Tropical Cyclone Ann Forms Over Coral Sea

Tropical Cyclone Ann formed over the Coral Sea on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Ann was located at latitude 16.3°S and longitude 158.7°E which put it about 875 miles (1410 km) east of Cairns, Australia.  Ann was moving toward the west at 5 m.p.h. (8 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 999 mb.

A distinct low level center of circulation became more evident in satellite images of a low pressure system over the eastern Coral Sea on Saturday and the system was designated as Tropical Cyclone Ann.  A rainband wrapped around the southern and western sides of the center of circulation.  A microwave satellite image indicated that the band may have wrapped completely around the center in the middle levels of the circulation.  Storms near the center of circulation began to generate upper level divergence which was pumping mass away from the tropical cyclone.  The circulation around Tropical Cyclone Ann was relatively small.  Winds to tropical storm force extended out about 85 miles (135 km) from the center of circulation in the southern half of Ann.

Tropical Cyclone Ann will move through an environment somewhat favorable for intensification during the next day or two.  Ann will move over water where the Sea Surface Temperature is near 28.5°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will cause some vertical wind shear.  The shear will inhibit intensification, but it is not likely to be strong enough to prevent intensification.  Tropical Cyclone Ann is likely to intensify during the next 24 hours.

The ridge will steer Tropical Cyclone Ann toward the west-northwest during the next two to three days.  On its anticipated track Tropical Cyclone Ann will approach the Cape York Peninsula in northern Queensland in about 72 hours.  Ann could bring gusty winds and locally heavy rain.

Elsewhere around the tropics in the southern hemisphere, Tropical Cyclone Lili was weakening near the coast of East Timor.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Lili was located at latitude 9.1°S and longitude 126.8°E which put it about 120 miles (195 km) east-northeast of Suai, East Timor.  Lili was moving toward the west at 4 m.p.h. (6 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 1000 mb.