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Tropical Cyclone Mitchell Moves Over Western Australia

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Tropical Cyclone Mitchell moved over the coast of Western Australia south of Carnarvon on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Mitchell was located at latitude 25.8°S and longitude 114.2°E which put the center about 70 miles (110 km) south-southeast of Carnarvon, Australia.  Mitchell was moving toward the south-southeast at 11 m.p.h. (17 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.

The Australian Bureau of Meteorology issued a Warning that was in effect for the portion of the coast from Carnarvon to Overlander Roadhouse.  The Warning included Denham.

Tropical Cyclone Mitchell was the equivalent of a tropical storm at the time it moved over the coast of Western Australia.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Mitchell’s circulation.

A weather station in Carnarvon, Australia measured a sustained wind speed of 43 m.p.h. (69 km/h) and a wind gust of 63 m.p.h. (102 km/h).

Tropical Cyclone Mitchell will move around the southwestern part of a high pressure system that is over Australia.  The high pressure system will steer Mitchell toward the south-southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Mitchell will move inland over Western Australia.  The center of Mitchell’s circulation will pass east of Denham.

Tropical Cyclone Mitchell will bring gusty winds and locally heavy rain to the area between Denham and Overlander Roadhouse during the next few hours.  Heavy rain could cause floods in some locations.

Flood Watches are in effect for the Gascoyne River, the Avon River, the Moore River, the Hill River, the Greenough River, the Murchison River, the Wooramel River, the Linden-Minilya Rivers, and the Yarra Yarra Lakes District.

Tropical Cyclone Mitchell Passes Near Exmouth

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Tropical Cyclone Mitchell was passing near Exmouth in Western Australia on Sunday morning.  At 10:00 a.m. EST on Sunday the center of Tropical Cyclone Mitchell was located at latitude 22.0°S and longitude 113.8°E which put the center about 25 miles (40 km) north-northwest of Exmouth, Australia.  Mitchell was moving toward the west-southwest at 9 m.p.h. (15 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 983 mb.

The Australian Bureau of Meteorology issued a Warning that was in effect for the portion of the coast from Onslow to Overlander Roadhouse.  The Warning included Exmouth, Carnarvon, and Denham.  The Warning extended inland to include Gascoyne Junction.

Even though the center of Tropical Cyclone Mitchell remained offshore, Mitchell was producing strong winds along the coast of Western Australia.  A weather station at the Onslow airport measured a sustained wind speed of 59 m.p.h. (95 km/h) and a wind gust of 75 m.p.h. (120 km/h).

Tropical Cyclone Mitchell weakened on Saturday night even though the center of Mitchell remained over water.  Southeasterly winds blowing into the southwestern part of Mitchell’s circulation appeared to pull drier air from the interior of Western Australia into the western side of the circulation.  The drier air caused many of the thunderstorms in the southwestern part of Tropical Cyclone Mitchell to weaken.  Thunderstorms were still occurring in bands in the other parts of Mitchell’s circulation.  Since there were fewer thunderstorms near the center of Mitchell, those thunderstorms generated less upper level divergence.  Less upper level divergence meant that the thunderstorms pumped less mass away from the tropical cyclone.  The removal of less mass caused the surface pressure to increase.

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

Tropical Cyclone Mitchell will move through an environment that will be unfavorable for intensification during the next 24 hours.  Mitchell will move over water where the Sea Surface Temperatures are near 29°C.  However, it will move under the western end of an upper level ridge that is over Australia.  The upper level ridge will produce northwesterly winds that will blow toward the top of Mitchell’s circulation.  Those winds will cause the vertical wind shear to increase.  In addition, Tropical Cyclone Mitchell is likely to continue to pull drier air into its circulation.  The combination of more vertical wind shear and drier air will cause Tropical Cyclone Mitchell to weaken slowly during the next 24 hours.

Tropical Cyclone Mitchell will move around the western end of a high pressure system that is over Australia.  The high pressure system will steer Mitchell toward the south during the next 24 hours.  On its anticipated track, the center of Tropical Cyclone Mitchell will make landfall on the coast of Western Australia near Cape Cuvier and Carnarvon in 12 hours.

Tropical Cyclone Mitchell will bring strong winds and heavy rain parts of Western Australia near Cape Cuvier and Carnarvon.  Heavy rain is likely to cause floods in some locations.

Flood Watches are in effect for the Gascoyne River, the Ashburton River, the Fortescue River, the Greenough River, the Murchison River, the Wooramel River, the Pilbara Coastal Rivers, and the Yarra Yarra Lakes District.

Tropical Cyclone Mitchell Intensifies to Equivalent of Hurricane/Typhoon

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Tropical Cyclone Mitchell intensified to the equivalent of a hurricane/typhoon as it moved near the coast of Western Australia on Saturday morning.  At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Mitchell was located at latitude 20.3°S and longitude 116.4°E which put the center about 50 miles (80 km) north-northwest of Karratha, Australia.  Mitchell was moving toward the southwest at 12 m.p.h. (19 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 973 mb.

The Australian Bureau of Meteorology issued a Warning that was in effect for the portion of the coast of Western Australia from Whim Creek to Coral Bay.  The Warning included Karratha, Dampier, Onslow, and Exmouth.

A Watch was in effect for the portion of the coast of Western Australia from Coral Bay to Carnarvon.

Tropical Cyclone Mitchell intensified to the equivalent of a hurricane/typhoon on Saturday morning.  The inner end of a rainband wrapped around the center of Michell’s circulation.  An eye appeared to be forming at the center of Tropical Cyclone Mitchell.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Mitchell’s circulation.  Storms near the center of Mitchell 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 Mitchell increased when Mitchell intensified.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Mitchell’s circulation.  Winds to tropical storm force extended out 100 miles (175 km) from the center of Tropical Cyclone Mitchell.

Tropical Cyclone Mitchell will move through an environment very favorable for intensification during the next 24 hours.  Mitchell will then move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Mitchell will intensify during the next 24 hours. .

Tropical Cyclone Mitchell will move around the northwestern part of a high pressure system that is over Australia.  The high pressure system will steer Mitchell toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Mitchell will make landfall in the Exmouth Gulf in less than 24 hours.

The center of Tropical Cyclone Mitchell is likely to make landfall on the coast of Western Australia between Onslow and Exmouth.  Mitchell will bring strong winds and heavy rain to locations near the Exmouth Gulf.  Heavy rain is likely to cause floods in some locations.

Flood Watches are in effect for the Gascoyne River, the Ashburton River, the Fortescue River, the Fitzroy River, the Greenough River, the Murchison River, the Wooramel River, the Pilbara Coastal Rivers, and the Yarra Yarra Lakes District.

Tropical Cyclone Mitchell Strengthens Near Western Australia

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Tropical Cyclone Mitchell strengthened near the coast of Western Australia on Friday morning.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Mitchell was located at latitude 18.7°S and longitude 119.4°E which put the center about 145 miles (235 km) north-northeast of Port Hedland, Australia.  Mitchell was moving toward the west-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 994 mb.

The Australian Bureau of Meteorology issued a Warning that was in effect for the portion of the coast from De Grey to Mardie.  The Warning included Port Hedland, Karratha, and Dampier.

A Watch was in effect for the portion of the coast from Onslow to Coral Bay.  The Watch included Exmouth.

A Tropical Low near the coast of Western Australia strengthened on Friday morning and the Australian Bureau of Meteorology designated it as Tropical Cyclone Mitchell.

The circulation around Tropical Cyclone Mitchell was strengthening on Friday morning.  New thunderstorms continued to develop near the center of Mitchell’s circulation.  Bands of showers and thunderstorms were also revolving around the center of Tropical Cyclone Mitchell.  Storms near the center of Mitchell 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 Mitchell was small.  Winds to tropical storm force extended out 65 miles (105 km) from the center of Mitchell’s circulation.

Tropical Cyclone Mitchell will move through an environment very favorable for intensification during the next 24 hours.  Mitchell will then move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Mitchell will intensify during the next 24 hours.  Mitchell could intensify rapidly to the equivalent of a hurricane/typhoon.

Tropical Cyclone Mitchell will move around the northwestern part of a high pressure system that is over Australia.  The high pressure system will steer Mitchell toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone will be north of Dampier in 24 hours.

The strongest winds in Tropical Cyclone Mitchell will remain north of the coast of Western Australia on Friday.  Bands in the southern half of Mitchell’s circulation could bring strong winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for the Gascoyne River, the Ashburton River, the Fortescue River, the Fitzroy River, and the Pilbara Coastal Rivers.

Tropical Low Prompts Warning for Western Australia

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The potential risk posed by a Tropical Low prompted the Australia Bureau of Meteorology to issue a Warning for a portion of the coast of Western Australia on Thursday.  At 10:00 p.m. EST on Thursday the center of a Tropical Low was located at latitude 17.9°S and longitude 121.5°E which put the center about 25 miles (40 km) west-northwest of Broome, Australia.  The Tropical Low was moving toward the west at 8 m.p.h. (13 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.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast of Western Australia from Pardoo Roadhouse to Whim Creek.  The Warning included Port Hedland.

The Australian Bureau of Meteorology issued a Watch for the portion of the coast of Western Australia from Whim Creek to Exmouth Gulf.  The Watch included Karratha,Dampier, and Onslow.

A low pressure system strengthened on Thursday when it moved over the South Indian Ocean near Broome, Australia.  The Australian Bureau of Meteorology designated the system as a Tropical Low.  The U.S. Joint Typhoon Warning Center designated the system as Tropical Cyclone 20S.

The Tropical Low started to strengthen on Thursday as soon as it moved over the water in the South Indian Ocean.  More thunderstorms formed near the center of the Tropical Low.  Thunderstorms also developed in bands 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 removal of mass caused the surface pressure to start to decrease.

The Tropical Low will move through an environment very favorable for intensification during the next 24 hours.  The Tropical Low will then move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The Tropical Low will intensify during the next 24 hours.  It could intensify rapidly to the equivalent of a hurricane/typhoon.

The Tropical Low will move around the northwestern part of a high pressure system that is over Australia.  The high pressure system will steer the Tropical Low toward the west-southwest during the next 24 hours.  On its anticipated track, the Tropical Low will be north of Port Hedland in 24 hours.

The center of the Tropical Low is likely to stay north of the coast of Western Australia on Friday.  Bands in the southern half of the Tropical Low could bring gusty winds and locally heavy rain to portions of the coast.

Tropical Cyclone Bianca Weakens Rapidly

Tropical Cyclone Bianca weakened rapidly over the South Indian Ocean west of Australia on Wednesday.  At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Bianca was located at latitude 25.7°S and longitude 102.7°E which put the center about 730 miles (1175 km) west of Carnarvon, Australia.  Bianca was moving toward the south-southeast 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 999 mb.

Tropical Cyclone Bianca weakened rapidly over the South Indian Ocean west of Australia on Wednesday.  An upper level trough west of Australia produced strong northwesterly winds that blew across the top of Tropical Cyclone Bianca.  Those winds caused strong vertical wind shear.  The vertical wind shear blew the upper part of Bianca’s circulation to the southeast of the circulation in the lower levels.

The circulation of Tropical Cyclone Bianca consisted of bands of showers and lower clouds that were revolving around the low level center of circulation.  Strong vertical wind shear was blowing the tops off of clouds that rose higher into the atmosphere.

The circulation around Tropical Cyclone Bianca was small.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Bianca’s circulation.

Tropical Cyclone Bianca will move through an environment that will be unfavorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 23°C.  It will move under the eastern side of an upper level trough over the South Indian Ocean.  The upper level trough will continue to produce strong northwesterly winds that will blow across the top of Bianca’s circulation.  Those winds will cause strong vertical wind shear.  Cooler water and strong vertical wind shear will cause Tropical Cyclone Bianca to continue to weaken during the next 24 hours.

Since the circulation around Tropical Cyclone Bianca exists only in the lower levels of the atmosphere, Bianca will be steered by the weather features near the surface.  Bianca will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will move farther away from Western Australia.

Tropical Cyclone Bianca Strengthens to Equivalent of Major Hurricane

Tropical Cyclone Bianca strengthened to the equivalent of a major hurricane on Monday night.  At 4:00 a.m. EST on Tuesday the center of Tropical Cyclone Bianca was located at latitude 22.3°S and longitude 102.0°E which put the center about 765 miles (1235 km) west of the Exmouth, Australia.  Bianca was moving toward the south-southwest at 11 m.p.h. (17 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. (235 km/h).  The minimum surface pressure was 962 mb.

Tropical Cyclone Bianca strengthened to the equivalent of a major hurricane over the South Indian Ocean west of Australia on Monday night.  A circular eye with a diameter of 20 miles (32 km) was at the center of Bianca’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 revolved around the center of Bianca’s circulation.  Storms near the center of Bianca generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Bianca was small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Bianca’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Bianca.

The Hurricane Intensity Index (HII) for Tropical Cyclone Bianca was 20.6.  The Hurricane Size Index (HSI) was 9.3 and the Hurricane Wind Intensity Size Index (HWISI) was 29.9.

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

Tropical Cyclone Bianca will move around the western part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will move parallel to the coast of Western Australia.

Tropical Cyclone Bianca Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Bianca strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean on Sunday night.  At 4:00 a.m. EST on Monday the center of Tropical Cyclone Bianca was located at latitude 19.3°S and longitude 103.3°E which put the center about 645 miles (1040 km) southeast of the Cocos Islands.  Bianca was moving toward the southwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 985 mb.

Tropical Cyclone Bianca rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean southeast of the Cocos Islands during Sunday night.  The inner end of a rainband wrapped around the center of Bianca’s circulation.  A circular eye formed at the center of Tropical Cyclone Bianca.  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 revolved around the center of Bianca’s circulation.  Storms near the center of Bianca 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 Bianca was small.  Winds to hurricane/typhoon force extended out 20 miles (3o km) from the center of Bianca’s circulation.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Tropical Cyclone Bianca.

Tropical Cyclone Bianca will move through an environment favorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level ridge over the South Indian Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Bianca is likely to continue to intensify during the next 24 hours.

Tropical Cyclone Bianca will move around the northwestern part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will remain far to the southeast of the Cocos Islands.

Tropical Cyclone Alfred Forms over the Coral Sea

Tropical Cyclone Alfred formed over the Coral Sea on Sunday.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Alfred was located at latitude 14.3°S and longitude 153.7°E which put the center about 560 miles (900 km) east-northeast of Cairns, Australia.  Alfred was moving toward the east at 8 m.p.h. (13 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 990 mb.

A low pressure system over the Coral Sea strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Alfred.  The circulation around Tropical Cyclone Alfred exhibited more organization on Sunday.  More thunderstorms formed near the center of Alfred’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Cyclone Alfred.  Storms near the center of Alfred 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 Alfred was fairly large.  Winds to tropical storm force extended out 180 miles (290 km) from the center of Alfred’s circulation.

Tropical Cyclone Alfred will move through an environment favorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Coral Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Alfred will intensify during the next 24 hours.

Tropical Cyclone Alfred will move around the southern side of a high pressure system that is near the Equator.  The high pressure system will steer Alfred toward the east during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move farther away from Australia.  Alfred is like to start to move toward the south early next week.

Elsewhere, Tropical Cyclone Bianca formed over the South Indian Ocean northwest of Australia.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Bianca was located at latitude 17.0°S and longitude 106.9°E which put the center about 590 miles (950 km) northwest of Exmouth, Australia.  Bianca was moving toward the west-southwest at 15 m.p.h. (24 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 998 mb.

Tropical Cyclone Gamane Brings Wind and Rain to Northern Madagascar

Tropical Cyclone Gamane brought strong winds and heavy rain to northern Madagacar on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Cyclone Gamane was located at latitude 13.5°S and longitude 49.1°E which put it about 25 miles (40 km) south of the Ambilobe, Madagascar. Gamane was moving toward the southwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 991 mb.

Tropical Cyclone Gamane rapidly intensified to the equivalent of a hurricane/typhoon before it made landfall on the coast of northern Madagascar near Iharana on Tuesday night. The circulation around Gamane was small at the time of landfall. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Tropical Cyclone Gamane at the time of landfall. Winds to tropical storm force only extended out 65 miles (105 km) from the center of Gamane’s circulation.

Tropical Cyclone Gamane weakened after the center of circulation moved over land. However, the circulation around Tropical Cyclone Gamane remained well organized. Thunderstorms were still occurring near the center of Gamane’s circulation. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center of Gamane generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 65 miles (105 km) from the center of Tropical Cyclone Gamane.

Tropical Cyclone Gamane will move around the western end of a high pressure system over the South Indian Ocean. The high pressure system will steer Gamane toward the south during the next 24 hours. On its anticipated track, Tropical Cyclone Gamane will move toward the south over northern Madagascar. Gamane will continue to weaken while the center of circulation is over land. Even though Tropical Cyclone Gamane will weaken, it will continue to drop heavy rain over parts of northern Madagascar. Heavy rain will cause floods in some locations.

An upper level trough southwest of Madagascar will start to steer Tropical Cyclone Gamane toward the southeast in a day or so. The center of Gamane is likely to move back over the Southwest Indian Ocean on Friday. Tropical Cyclone Gamane could strengthen once the center of circulation moves back over water. Gamane could affect La Reunion and Mauritius during the weekend.