Category Archives: Australian Region

Tropical Cyclone Joyce Brings Wind and Rain to Western Australia

Tropical Cyclone Joyce brought wind and rain to Western Australia on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Joyce was located at latitude 19.6°S and longitude 120.9°E which put it about 20 miles (35 km) northeast of Wallal Downs, Australia.  Joyce was moving toward the southwest 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 989 mb.

The center of Tropical Cyclone Joyce moved along the coast of Western Australia from Bidyadanga toward Wallal Downs on Thursday.  Tropical Cyclone Joyce brought gusty winds up to 60 m.p.h. (95 km/h) to portions of the coast.  The fact that almost half the circulation of Joyce was flowing over land kept the tropical cyclone from intensifying significantly.  Several bands of showers and thunderstorms were occurring in the southwestern half of the circulation.  Fewer showers and thunderstorms were in the northeastern half of Tropical Cyclone Joyce, except for a couple of small bands in the periphery of the circulation near Cape Leveque.

Tropical Cyclone Joyce is being steered toward the southwest by a subtropical ridge and that motion is expected to continue for several more days.  On its anticipated track the center of Joyce will move inland near Wallal Downs.  It will continue inland on Friday and the center will pass near Shay Gap and Marble Bar.  A Tropical Cyclone Warning is in effect for the portion of the coast from Bidyadanga to De Grey.  Tropical Cyclone Joyce will gradually weaken when it moves inland, but it will continue to drop locally heavy rain over parts of Western Australia when it moves inland.  The Australian Bureau of Meteorology has issued Flood Warnings and Watches for portions of Western Australia.

Tropical Cyclone Joyce Develops Near Western Australia

Tropical Cyclone Joyce developed near Western Australia on Wednesday when a Tropical Low moved over the South Indian Ocean.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Joyce was located near latitude 17.0°S and longitude 121.6°E which put it about 80 miles (125 km) north-northwest of Broome, Australia.  Joyce was moving toward the south-southwest at 5 m.p.h. (7 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 990 mb.

A Tropical Low moved from Western Australia off the coast and over the warm water of the South Indian Ocean on Wednesday.  The circulation of the system organized after the center moved over water and the inner core became more well developed.  The Australian Bureau of Meteorology designated the system as Tropical Cyclone Joyce.  A Tropical Cyclone Warning was issued for the portion of the coast from Cape Leveque to De Grey including Broome and adjacent inland parts of Western Australia.  A Tropical Cyclone Watch was issued for the portion of the coast from De Grey to Dampier including Port Headland, Karratha and adjacent inland areas.

The circulation of Tropical Cyclone Joyce exhibited the classical appearance of an organizing tropical cyclone on Wednesday.  There was a well defined low level center of circulation.  Numerous bands of showers and thunderstorms were revolving around the center of circulation.  Storms in the core of Joyce were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Joyce will be moving through an environment favorable for intensification during the next day or so.  Joyce will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Warm water and little vertical wind shear will allow Joyce to strengthen and it could intensify rapidly.  Tropical Cyclone Joyce is forecast to strengthen into the equivalent of a hurricane/typhoon during the next 36 hours.

Tropical Cyclone Joyce is moving around the western end of a subtropical ridge which is steering Joyce toward the south-southwest.  The ridge is forecast to steer Joyce in a general southwesterly direction during the next several days.   On its anticipated track the center of Tropical Cyclone Joyce could make landfall on the coast of western Australia between Wallal Downs and De Grey in about 36 hours.

Tropical Low Forms Over Western Australia

A Tropical Low formed over Western Australia on Monday and a Tropical Cyclone Watch was issued for a portion of the coast.  At 2:00 p.m. EST on Monday the center of the Tropical Low was located at latitude 15.9°S and longitude 126.1°E which put it about 135 miles (220 km) west-southwest of Wyndham, Australia.  It was moving toward the southwest a 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 20 m.p.h. (30 km/h) and there were wind gusts to 50 m.p.h. (85 km/h).  The minimum surface pressure was 1005 mb.  The Australia Bureau of Meteorology has issued a Tropical Cyclone Watch for the portion of the coast of Western Australia from Kuri Bay to Wallal Downs including Broome.

The circulation of the Tropical Low is still organizing.  There is a broad low level center of circulation, but there are not many showers and thunderstorms near the center.  There are numerous bands of showers and storms developing in bands on the eastern and western peripheries of the circulation.  The strongest wind gusts are occurring in those storms.  The lack of storms near the center of circulation is keeping the system from generating much upper level divergence.

The core of the Tropical Low is likely to remain over land for another 12-24 hours, which will inhibit the organization of the circulation.  When the center moves off the coast and over the South Indian Ocean, it will move into an environment favorable for intensification.  The Sea Surface Temperature of the water west of the coast of Western Australia is near 30°C.  The Tropical Low is moving north of the axis of a subtropical ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation, but there is not a lot of vertical wind shear.  The Tropical Low is likely to strengthen when it moves over water and it could intensify rapidly if a more concentrated center of circulation develops.

A subtropical ridge is current steering the Tropical Low toward the southwest, but a general motion toward the west-southwest is expected during the next 24 to 48 hours.  The Tropical Low will reach the western end of the ridge in about two days and then it will turn more toward the south.  On its anticipated track the center of the Tropical Low is expected to move off the coast between Kuri Bay and Derby on Tuesday.  The center is forecast to pass near Cape Leveque and then turn south toward Wallal Downs.

Elsewhere over the South Indian Ocean, Tropical Cyclone Ava continued to swirl near southern Madagascar and stronger Tropical Cyclone Irving was passing well to the south of Diego Garcia.  At 4:00 p.m. EST on Monday the center of Tropical Storm Ava was located at latitude 27.7°S and longitude 46.8°E which put it about 180 miles (295 km) south of Farodofay, Madagascar.  Ava was moving toward the west-southwest at 17 m.p.h. (27 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 994 mb.

At 4:00 p.m. EST on Monday the center of Tropical Cyclone Irving was centered at latitude 19.6°S and longitude 76.1°E which put it about 875 miles (1415 km) south-southeast of Diego Garcia.  Irving was moving toward the west-southwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 960 mb.  Tropical Cyclone Irving was the equivalent of a Category 2 hurricane on the Saffir-Simpson Scale.

Former Tropical Cyclone Hilda Drops Heavy Rain Over Western Australia

Former Tropical Cyclone Hilda dropped heavy rain over Western Australia on Friday.  At 11:00 a.m. EST on Friday the center of former Tropical Cyclone Hilda was located at latitude 22.7°S and longitude 123.6°E which put it about 50 miles (80 km) east-northeast of Telfer, Australia.  Hilda was moving toward the southeast at 6 m.p.h. (10 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 999 mb.

Although the center has been over land for more than a day, the circulation of former Tropical Cyclone Hilda is still well organized.  There is a well defined low level center of circulation and strong thunderstorms are occurring around the center.  Several bands of thunderstorms are revolving around the core of the circulation.  Storms near the core are generating strong upper level divergence which is pumping away mass.  The upper level divergence is preventing the surface pressure from increasing and that is allowing the surface low to maintain its intensity.

Storms near the core of former Tropical Cyclone Hilda and the rainbands are dropping heavy rain over parts of Western Australia.  That region is normally dry and the potential for flash floods exists.  The Australian Bureau of Meteorology has issued Flood Warnings for the Sandy Desert and West Kimberly District.  They have also issued Flood Watches for the De Grey River, Salt Lakes and Warburton District Catchments.  The storms generated by former Tropical Cyclone Hilda could also cause localized wind damage, but the greatest risk is posed by the heavy rain.

Tropical Cyclone Hilda Develops on Coast of Western Australia

A Tropical Low near the coast of Western Australia strengthened and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Hilda. At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Hilda was located at latitude 18.0°S and longitude 122.1°E which put it about 10 miles (15 km) west-southwest of Broome, Australia.  Hilda was moving toward the south-southwest at 8 m.p.h. (12 km/h).  The maximum sustained wind speed was 50 m.p.h. (85 km/h) and there were wind gusts to 85 m.p.h. (140 km/h).  The minimum surface pressure was 985 mb.  Broome Port reported a wind gust to 86 m.p.h. (139 km/h).

The center of the Tropical Low moved off the coast of Western Australia and the core of the circulation strengthened.  Thunderstorms in the core of Tropical Cyclone Hilda generated strong upper level divergence which pumped mass away from the center of circulation.  The removal of mass allowed the surface pressure to decrease quickly and the wind speeds increased.  The strongest winds were occurring over water near the center of circulation.  Additional bands of showers and thunderstorms were revolving around the core of the circulation.  Hilda is a small tropical cyclone.  Winds to tropical storm force only extend out about 35 miles (55 km) from the center of circulation.

Tropical Cyclone Hilda will be moving through an environment that will support further intensification during the next 12 hours.  The Sea Surface Temperature of the water near the coast of Western Australia is near 30°C.  Tropical Cyclone Hilda is underneath an upper level ridge and the upper level winds are weak.  There is little vertical wind shear.  The proximity to land is the only factor preventing rapid intensification of Tropical Cyclone Hilda.  Almost half of the circulation is over land and the increased friction is reducing the wind speeds in that part of Tropical Cyclone Hilda.

Tropical Cyclone Hilda is moving around the western end of a subtropical ridge, which is steering the tropical cyclone toward the south-southwest.  A general motion toward the south-southwest is expected to continue for another 12 to 24 hours.  On its anticipated track the center of Tropical Cyclone Hilda could pass near Bidyadanga during the next 6 to 12 hours.  Hilda will bring gusty winds capable of producing localized minor wind damage.  A Warning is in effect for the portion of the coast from Beagle Bay to Pardoo Roadhouse.  The core of Tropical Cyclone Hilda will drop locally heavy rain near the coast of Western Australia and flash flooding is possible.

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 Cyclone Dahlia Forms Southwest of Indonesia

Tropical Cyclone Dahlia formed southwest of Indonesia on Wednesday.  At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Dahlia was located at latitude 8.4°S and longitude 101.5°E which put it about 320 miles (520 km) west-northwest of Christmas Island.  Dahlia was moving toward the east 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 center of circulation developed in a cluster of thunderstorms previously designated as Invest 96S and the Australian Bureau of Meteorology named the system Tropical Cyclone Dahlia.  The circulation of Dahlia is still organizing.  A primary rainband wrapped around the southern and western sides of the center.  Additional bands of showers and thunderstorms formed in the western half of the circulation.  Fewer thunderstorms formed in the eastern half of Dahlia.  The thunderstorms near and to the west of the center were generating upper level divergence which was pumping mass away to the west of the tropical cyclone.

Tropical Cyclone Dahlia will be moving through an environment favorable for intensification during the next several days.  Dahlia will move over water where the Sea Surface Temperature is near 29°C.  Dahlia is underneath the northern part of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear, which may be the reason why most of the thunderstorms are west of the center of circulation.  The shear is strong enough to slow the intensification of Dahlia, but it is not strong enough to prevent the tropical cyclone from strengthening.  Tropical Cyclone Dahlia is likely to likely to intensify during the next 24 to 48 hours.

The steering winds around Dahlia are relatively weak and the tropical cyclone is moving slowly toward the east.  The upper level ridge is forecast to shift north and stronger westerly winds are likely to steer Tropical Cyclone Dahlia toward the east at a faster speed.  When Dahlia reaches the southern portion of the upper level ridge in a couple of days, northerly winds diverging from the ridge are likely to steer the tropical cyclone toward the south.

Tropical Cyclone Cempaka Develops South of Java

The organization of a small area of low pressure (also known as Invest 95S) south of Java increased early on Monday and the Badan Meteorologi Klimatologi Dan Geofisika (BMKG) Tropical Cyclone Warning Center in Jakarta designated the system as Tropical Cyclone Cempaka.  At 7:00 a.m. EST on Monday the center of Tropical Cyclone Cempaka was located at latitude 8.8°S and longitude 110.8°E which put it about 70 miles (115 km) south-southeast of Yokyakarta, Indonesia.  Cempaka was moving toward the east- northeast 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 997 mb.

Tropical Cyclone Cempaka has a small but well developed center of circulation.  Radar images from BKMG showed an eyelike feature at the center of circulation.  The strongest winds are occurring in a ring of showers and thunderstorms that surrounds the center.  The stronger storms are in the eastern half of the ring.  Other narrow rainbands are developing outside the core of Cempaka.  Thunderstorms around the center are generating some upper level divergence which is pumping mass away from the tropical cyclone.  Winds to tropical storm force extend out about 40 miles (65 km) from the center of circulation.

Tropical Cyclone Cempaka will be in an environment somewhat favorable for intensification during the next 24 to 48 hours.  Cempaka will move over water where the Sea Surface Temperature is near 29°C.  Tropical Cyclone Cempaka is under an upper level ridge and the upper level winds are weak.  There is little vertical wind shear over the tropical cyclone.  The core of Tropical Cyclone Cempaka is near Java.  Part of the circulation is flowing over Java and nearby islands and friction from those islands is slowing the winds.  Interaction with land is the primary factor inhibiting intensification.  If the center of Tropical Cyclone Cempaka remains south of Java, then it has a chance to intensify.  If Cempaka moves closer to Java, then it could weaken.  Also, since Cempaka is a very small tropical cyclone, an increase in the speed of the upper level winds could blow the top off of the circulation.

Since Tropical Cyclone Cempaka is underneath an upper level ridge, the steering winds are weak.  Cempaka is south of the center of the ridge and weak westerly winds are steering the tropical cyclone slowly toward the east-northeast.  Tropical Cyclone Cempaka is forecast to meander south of Java for several more days because of the weak stearing winds.

Tropical Cyclone Cempaka is producing locally heavy rain over parts of Java, Bali and nearby islands.  The locally heavy rain could cause flash floods as Cempaka meanders south of Java during the next day or two.

Low Pressure System Forms South of Java

A small, but well organized area of low pressure developed just to the south of Java on Sunday.  The low pressure system is currently designated as Invest 95S, but it could become a tropical cyclone during the next several days.  At 10:00 p.m. EST on Sunday the center of Invest 95S was located at latitude 8.9°S and longitude 109.8°E which put it about 100 miles (160 km) southwest of Yogyakarta, Indonesia.  It was moving toward the northeast at 4 m.p.h. (6 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.

The circulation of Invest 95S is small but well formed.  There is a distinct low level center of circulation.  Two well formed narrow rainbands wrapped around the southern and northeastern sides of the center.  Other rainbands developed just outside the core of the circulation.  Storms near the center of circulation were generating some upper level divergence which was pumping out mass and allowing the surface pressure to decrease.

Invest 95S will move through an environment that is mostly favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  Invest 95S is near the center of an upper level ridge.  The upper level winds blowing over the top of the low pressure system are weak and there is not a lot of vertical wind shear.  The proximity of the circulation to Java is the only factor likely to inhibit intensification.  If the center of circulation remains south of Java, then there is a good chance it could intensify into a tropical cyclone.

The ridge north of Invest 95S is steering the system slowly toward the northeast and a general easterly motion is expected to continue during the next 24 hours.  Guidance from numerical models diverges in a day or so.  Some models to suggest the northeasterly motion will continue and the low pressure system will move across Java.  Other models predict a turn toward the south in a day or so.  There is a high degree of uncertainty about the future track of Invest 95S.

Tropical Cyclone Frances Intensifies Into Equivalent of a Hurricane

Tropical Cyclone Frances intensified into the equivalent of a hurricane/typhoon on Friday as it moved northwest of Australia.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Frances was located at latitude 12.6°S and longitude 124.1°E which put it about 200 miles (325 km) north of Kuri Bay, Australia.  Frances was moving toward the west-southwest at 9 m.p.h. (14 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 Frances intensified into the equivalent of a hurricane/typhoon when it moved through a favorable environment.  Frances moved over water where the Sea Surface Temperature (SST) was near 30°C and the upper level winds were weak.  A primary rainband wrapped almost entirely around the center of circulation and an eyelike feature seemed to be indicated on some satellite imagery.  Thunderstorms around the eye generated upper level divergence which pumped out mass and the circulation assumed a more symmetrical circulation.  Other bands of showers and thunderstorms formed in the outer portions of the circulation.

Tropical Cyclone Frances may have reached its peak intensity.  Frances will continue to move over water where the SST is near 30°C.  However, it is about to move near the western end of an upper level ridge where there are stronger northerly winds.  Those stronger winds will create much more vertical wind shear and Tropical Cyclone Frances is likely to weaken during the next several days.

A subtropical ridge to the east of Frances is steering the tropical cyclone toward the west-southwest and that general motion is forecast to continue for the next several days.  On its anticipated track Tropical Cyclone Frances poses no threat to Western Australia, although it could cause increased wave action along the coast.