Tag Archives: Tropical Low

Tropical Low Develops Near West Timor

A tropical low developed near West Timor on Saturday. At 8:00 p.m. EDT on Saturday the center of the tropical low was located at latitude 10.6°S and longitude 123.6°E which put it about 30 miles (50 km) west of Kupang, Indonesia. The tropical low was nearly stationary. 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 1003 mb.

An area of low pressure near West Timor exhibited more organization on Saturday and the Australian Bureau of Meteorology classified the system as a tropical low. Visible and microwave satellite images showed a distinct low level center of circulation. More thunderstorms formed near the center of the tropical low. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center began to generate upper level divergence that pumped mass away from the tropical low.

The tropical low will move through an environment favorable for intensification during the next several days. The tropical low will move over water where the Sea Surface Temperatures will be near 30°C. It will move under the axis of an upper level ridge. The winds are weak near the axis of the ridge and there will be little vertical wind shear. The tropical low is likely to intensify into the equivalent of a tropical storm during the next 24 hours. It could strengthen into the equivalent of a hurricane/typhoon by early next week.

The tropical low will be in an area where the steering winds are weak during the next 24 hours. It will remain near West Timor during that time. Thunderstorms in rainbands will drop locally heavy rain and flash floods could occur. A high pressure system over Australia will begin to steer the tropical low toward the southwest in a day or so. On its anticipated track the system will remain northwest of Western Australia during the next few days.

Tropical Low Forms over Gulf of Carpentaria

A Tropical Low formed over the Gulf of Carpentaria on Monday afternoon. At 1:00 p.m. EST on Monday the center of the Tropical Low was located at latitude 15.4°S and longitude 139.5°E which put it about 150 miles (240 km) west of Kowanyama, Australia. It was moving toward the east at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h). The minimum surface pressure was 1003 mb.

Watches were issued for the portion of the coast of Queensland from Aurukun to Karumba and for Mornington Island.

Thunderstorms formed near the center of a low pressure system over the southeastern Gulf of Carpentaria on Monday afternoon and the Australian Bureau of Meteorology designated the system as a Tropical Low. The circulation around the Tropical Low was still organizing. Thunderstorms continued to develop near the center of circulation. More thunderstorms were also forming in bands revolving around the center of the Tropical Low. Storms near the center of circulation began to generate upper level divergence which pumped mass away from the Tropical Low.

The Tropical Low will move through an environment favorable for intensification during the next 24 hours. The Tropical Low will move over water in the Gulf of Carpentaria where the Sea Surface Temperature is near 30°C. It will move under the center of an upper level ridge. The winds are weak near the center of the ridge and there will be little vertical wind shear. The Tropical Low will intensify during the next 24 hours and it could strengthen into the equivalent of a tropical storm.

The Tropical Low will move south of a high pressure system centered north of Australia during the next 24 hours. The high will steer the Tropical Low toward the east. On its anticipated track the Tropical Low could approach the southwest coast of Queensland in about 24 hours. The steering winds could weaken in a day or so and the Tropical Low could stall near the coast. Even if the center of the Tropical Low does not make landfall, bands in the eastern half of the circulation could drop heavy rain over parts of northern Queensland. Heavy rain could cause floods in some locations.

Tropical Low Strengthens over Gulf of Carpentaria

A tropical low strengthened over the Gulf of Carpentaria on Saturday. At 1:00 p.m. EST on Saturday the center of the tropical low was located at latitude 15.8°S and longitude 138.5°E which put it about 75 miles (120 km) northwest of Mornington Island. The tropical low was moving toward the southeast at 7 m.p.h. (11 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.

A Watch was in effect for the portion of the coast from the border between the Northern Territory and Queensland to Pormpuraaw. The Watch included Mornington Island.

The circulation around the tropical low exhibited better organization on Saturday. More thunderstorms developed near the center of circulation. Storms near the center generated upper level divergence which pumped mass away from the tropical low. The removal of mass was causing the surface pressure to decrease. Bands of showers and thunderstorms were revolving around the center of the tropical low.

The tropical low will move through an environment favorable for intensification during the next 24 hours. The tropical low will move over water where the Sea Surface Temperature is near 30°C. It will move under the axis of an upper level ridge where the winds are weak. There will be little vertical wind shear. The tropical low will strengthen during the next 24 hours and it is likely to intensify to the equivalent of a tropical storm.

The tropical low will move south of a high pressure system centered north of Australia. The high 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 Queensland between Karumba and Gilbert River Mouth in about 24 hours. It will be the equivalent of a tropical storm when it makes landfall. The tropical low could stall when it moves inland, which would cause a prolonged period of heavy rain. Flash floods could occur in parts of northern Queensland.

Tropical Low Strengthens Over Gulf of Carpentaria

A Tropical Low designated as Invest 99P by some agencies strengthened over the Gulf of Carpentaria on Saturday.  At 4:00 p.m. EST on Saturday the center of the Tropical Low was located at latitude 14.3°S and longitude 138.2°E which put it about 110 miles (180 km) east of Groote Eylandt, Australia.  The Tropical Low was moving toward the south at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1000 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Numbulwar to Kowanyama including Mornington Island.

More bands of thunderstorms began to develop around a Tropical Low on Saturday.  The bands were revolving around the center of circulation.  The Tropical Low will move through an environment favorable for intensification during the next 24 hours.  It will move over water where the Sea Surface Temperature is near 30°C.  The Tropical Low is under an upper level ridge and the upper level winds are weak.  There will be little vertical wind shear and the Tropical Low is forecast to strengthen into a tropical cyclone.

The Tropical Low will move around the western end of a high pressure system.  The high will steer the Low toward the south.  On its anticipated track the Tropical Low will approach the coast of Australia near the border between Queensland and the Northern Territory.  It will bring gusty winds and locally heavy rain.  Heavy rain could cause flash floods in some locations.

Tropical Low Forms Northwest of Australia

A Tropical Low formed over the South Indian Ocean northwest of Australia on Saturday.  At 1:00 p.m. EST on Saturday the center of a Tropical Low was located at latitude 14.3°S and longitude 121.9°E which put it about 255 miles (410 km) north of Broome, Australia.  It was moving toward the south-southwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1002 mb.

A Watch was issued for the portion of Western Australia from Mitchell Plateau to Wallal Downs.

The circulation around the Tropical Low was still organizing.  It did not have a well developed center of circulation.  There was a clockwise rotation around a broad center.  Bands of showers and thunderstorms were beginning to form in the outer regions of the circulation.  Upper level divergence was pumping mass away from the Tropical Low and the surface pressure was decreasing.

The Tropical Low will move through an environment favorable for intensification during the next 24 to 48 hours.  It will move over water where the Sea Surface Temperature is near 30°C.  The Tropical Low will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The Tropical Low is likely to intensify into a named tropical cyclone and it could strengthen into the equivalent of a hurricane/typhoon.

The Tropical Low will move around the western end of a high pressure system centered near the north coast of Australia.  The high will steer the Tropical Low toward the south-southwest.  On its anticipated track the Tropical Low could approach the coast of Western Australia southwest of Cape Leveque in a day or two.

Tropical Cyclone Riley Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Riley strengthened into the equivalent of a hurricane/typhoon on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Riley was located at latitude 17.2°S and longitude 116.9°E which put it about 415 miles (675 km) north-northeast of Learmonth, Australia.  Riley was moving toward the west at 5 m.p.h. (8 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 976 mb.

Tropical Cyclone Riley strengthened, but the distribution of thunderstorms was asymmetrical.  The strongest winds were occurring in a band the curled around the northern half of the center of circulation.  Storms in the band were generating upper level divergence which was pumping mass away from the tropical cyclone.  Other bands of showers and thunderstorms were present in the western half of the circulation, but the bands in the eastern half of Tropical Cyclone Riley consisted primarily of showers and lower clouds.  Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of circulation and they were occurring mainly north of the center of Riley.  Winds to tropical storm force extended out about 130 miles (215 km) from the center.

Tropical Cyclone Riley was moving around the northwestern part of an upper level ridge.  The ridge was producing easterly winds which were blowing toward the top of the circulation.  Those winds appeared to converge with the upper level divergence on the east side of Riley to produce sinking motion in that part of the tropical cyclone.  The sinking motion was bringing drier air to the lower levels and it appeared to suppressing convection in that region.

Tropical Cyclone Riley may be close to its peak intensity.  Riley is currently over water where the Sea Surface Temperature is near 28°C, but it will move over cooler water during the next few days.  The upper level ridge will continue to produce easterly winds which will blow toward the top of the circulation.  Those winds could strengthen which would cause more vertical wind shear.  Riley could intensify during the next 24 hours, but it is more likely to gradually weaken during the next two or three days.

The ridge will steer Tropical Cyclone Riley toward the west-southwest during the next few days.  On its anticipated track Riley will remain north of the coast of Western Australia,  However, watches and warnings are in effect for portions of the coast in case the Tropical Cyclone Riley moves more toward the south.  A Tropical Cyclone Warning is in effect for the portion of the coast from Whim Creek to Onslow including Karratha and Dampier.  A Tropical Cyclone Watch is in effect from Onslow to Exmouth.

Elsewhere around Australia, a Tropical Low was dropping heavy rain over portions of northern Queensland.  At 1:00 p.m. EST the center of the Tropical Low was located at latitude 13.8°S and longitude 141.3°E which put it about 80 miles (125 km) north-northwest of Pormpuraaw, Australia.  It was moving toward the southeast at 6 m.p.h. (10 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 1002 mb.  Locally heavy rain could cause floods in parts of northern Queensland.

Tropical Low Prompts Warning for Northern Queensland

A tropical low over the Gulf of Carpentaria prompted the issuance of warnings and watches for northern Queensland on Thursday.  A Tropical Cyclone Warning was in effect for the portion of the coast from Mapoon to Karumba.  A Tropical Cyclone Watch was in effect for the portion of the coast from Karumba to the border between Queensland and the Northern Territory including Mornington Island.

At 7:00 p.m. EST on Thursday the center of the tropical low was located at latitude 13.0°S and longitude 139.9°E which put it about 135 miles (220 km) west of Weipa, Australia.  It was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1002 mb.

The circulation around the tropical low exhibited more organization on Thursday.  A band of showers and thunderstorms wrapped around the western and northern sides of the center of circulation.  Other bands of showers and thunderstorms were developing over the Gulf of Carpentaria.  Storms near the center of circulation began to generate upper level divergence which was pumping mass away in outflow channels to the northwest and southeast of the tropical low.

The tropical low will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The tropical low will be in an area where the upper level winds are weaker and the vertical wind shear will be limited.  The tropical low is likely to intensify during the next 24 to 36 hours and it is forecast to become a named tropical cyclone.

The tropical low is under the northeastern portion of an upper level low.  It is in a small region where the steering winds are weaker and the tropical low meandered over the eastern Gulf of Carpentaria on Thursday.  Northerly winds blowing around the upper level low are forecast to steer the tropical low toward the south during the next day or two.  On its anticipated path the tropical low is expected to move over the eastern Gulf of Carpentaria near the coast of Queensland.  If the tropical low follow its anticipated track, it will make landfall on the south coast of the Gulf of Carpentaria in about 48 hours.  However, any eastward deviation would bring the tropical low inland over Queensland much sooner.

Elsewhere, Tropical Cyclone Riley strengthened northwest of Australia.  At 7:00 p.m. EST on Thursday the center of Tropical Cyclone Riley was located at latitude 16.5°S and longitude 118.8°E which put it about 265 miles (425 km) north of Port Hedland, Australia.  Riley was moving toward the west at 4 m.p.h. (6 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 985 mb.  A Tropical Cyclone Watch was in effect for the portion of the coast from Whim Creek to Onslow, Australia including Karratha and Dampier.

Tropical Low Forms North of Australia

A Tropical Low formed north of Australia late on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of the Tropical Low as located at latitude 9.2°S and longitude 130.9°E which put it about 155 miles (250 km) north of Milikapiti, Australia.  It was moving toward the east at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (45 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1004 mb.  The Australian Bureau of Meteorology issued a Watch for the portion of the coast from Milingimbi to Daly River Mouth including Darwin and the Tiwi Islands.

A center of circulation developed in an area of showers and thunderstorms north of Australia late on Wednesday and the Australian Bureau of Meteorology classified the system as a Tropical Low.  The circulation was still organizing.  A short band of showers and thunderstorms wrapped around the southern and western sides of the center.  Other short rainbands were developing in other parts of the circulation.  Storms near the center of circulation were just beginning to generate upper level divergence.

The Tropical Low will move through an environment somewhat favorable for intensification.  It will mover over water where the Sea Surface Temperature is near 30°C.  Westerly winds in the upper levels will cause some vertical wind shear, which will inhibit intensification.  However, the shear is not likely to be strong enough to prevent intensification.  The Tropical Low is likely to strengthen during the next 24 hours.  After that time the intensity will be influenced by how much of the circulation is over Australia.

The Tropical Low is being steered to the east by westerly winds north of Australia.  Those winds are forecast to weaken and the Tropical Low is expected to turn south toward the coast of Australia.  A subtropical ridge over Australia is expected to turn the Tropical Low toward the southwest in a day or so.  On its anticipated track the Tropical Low could be near the northern coast of Australia in 24 to 36 hours.  It could pass near the Cobourg Peninsula, Melville Island and Bathurst Island.  The Tropical Low could also bring gusty winds and heavy rain to the area near Darwin.

Tropical Low Develops Near Coast of Western Australia

A distinct low level center of circulation developed in an area of thunderstorms near the coast of Western Australia on Tuesday and the Australian Bureau of Meteorology classified the system as a Tropical Low.  At 10:00 p.m. EST on Tuesday the center of the Tropical Low as located at latitude 17.2°N and 122.3°E which put it just inland east of Coulomb Point and about 55 miles (85 km) north of Broome, Australia.  The Tropical Low was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 998 mb.

Although the center of circulation was over land, the circulation of the Tropical Low became much better organized on Tuesday.  There was a well defined center of circulation and weather radar images indicated an eyelike feature at the center of the Tropical Low.  Several bands of showers and thunderstorms wrapped around the center of circulation.  Storms in the core of the Tropical Low were generating well developed upper level divergence which was pumping mass away in all directions.

The Tropical Low will move through an environment favorable for intensification during the next 24 to 36 hours.  The Sea Surface Temperature of the water off the coast of Western Australia is near 30°C.  The Tropical Low is underneath an upper level ridge and the upper level winds are not very strong.  There is little vertical wind shear.  The only factor inhibiting intensification is the fact that the center is still inland over Western Australia.  If the center moves over water as is forecast, the Tropical Low will intensify and it could intensify rapidly.

The Tropical Low is moving around the western end of a mid-level ridge which is steering it toward the southwest.  The ridge is forecast to steer the Tropical Low toward the southwest for another 12 to 24 hours.  When the Tropical Low reaches the western end of the ridge, it will move more toward the south.  On its anticipated track the center of the Tropical Low will move off the coast of Western Australia and over water during the next 6 to 12 hours.  The center of the Tropical Low is expected to pass west of Broome.  The Tropical Low could approach the coast of Western Australia between Bidyadanga and Wallal Downs in about 36 hours.

The Tropical Low will drop heavy rain along the coast of Western Australia during the next 48 hours.  It will also bring gusty winds and a Warning has been issued for the portion of the coast from Cape Leveque to De Grey.

Tropical Low Brings Wind and Rain to Northern Australia

A Tropical Low pressure system brought wind and rain to northern Australia on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of the Tropical Low was located at latitude 12.1°S and 131.5°E which put it about 45 miles (75 km) east-northeast of Darwin, Australia.  The Tropical Low was moving toward the west-southwest at 8 m.p.h. (12 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.

The circulation of the Tropical Low is not very well organized.  Many of the thunderstorms are occurring in the outer portions of the circulation.  There are mostly showers, and only a few thunderstorms, near the center of circulation.  There are a few rainbands near the periphery of the circulation, but there is not a well formed core at the center.  The poor organization is preventing the Tropical Low from generating much upper level divergence and as a result the surface pressure has changed little during the past 24 hours.

A significant portion of the circulation of the Tropical Low is over land and that is inhibiting development of the system.  In addition, an upper level ridge to the east of the Tropical Low is producing northerly winds which are blowing across the top of the circulation.  Those winds are causing moderate vertical wind shear which is also inhibiting development.  The Tropical Low is moving toward the west-southwest and the center is forecast to move over the Timor Sea.  If the center of circulation moves over the Timor Sea, it will move over water where the Sea Surface Temperature is near 30°C.  More energy from the water could offset the effects of the vertical wind shear and the Tropical Low could intensify into a tropical cyclone.

A subtropical ridge east of the Tropical Low is steering the system toward the west-southwest and that general motion is expected to continue during the next several days.  On its anticipated track the center of the Tropical Low will move near the northern coast of Australia.  If the center emerges over the Timor Sea, then the system could intensify into a tropical cyclone.  If the center remains over land, then further development will not occur.  In either case the Tropical Low will bring gusty winds and heavy rains to the northern coastal regions of the Northern Territory and Western Australia.