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Tropical Cyclone Hayley Brings Wind and Rain to Western Australia

Tropical Cyclone Hayley brought wind and rain to Western Australia on Tuesday.  At 10:00 a.m. EST on Tuesday the center of Tropical Cyclone Hayley was located at latitude 16.7°S and longitude 123.7°E which put the center about 50 miles (80 km) north-northwest of Derby, Australia.  Hayley was moving toward the east at 15 m.p.h. (24 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 969 mb.

A Warning was in effect for the region from north of Beagle Bay to south of Kuri Bay, Australia.

Tropical Cyclone Hayley made landfall on the coast of Western Australia south of Lombadina on Tuesday morning.  Hayley moved across the northern part of the Dampier Peninsula.  Tropical Cyclone Haley was currently over King Sound.

The circulation around Tropical Cyclone Hayley was small.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Hayley’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Hayley.

The Hurricane Intensity Index (HII) for Tropical Cyclone Hayley was 12.7.  The Hurricane Size Index (HSI) was 7.9 and the Hurricane Wind Intensity Size Index (HWISI) was 20.6.

Tropical Cyclone Hayley will move around the northeastern part of an upper level trough over Western Australia.  The upper level trough will steer Hayley toward the east during the next 24 hours.  On its anticipated track, Tropical Cyclone Hayley will make another landfall in Western Australia north of Derby in a few hours.

Tropical Cyclone Hayley will bring strong winds and locally heavy to parts of Western Australia north and east of Derby.  Heavy rain could cause flash floods in some locations,

The Australian Bureau of Meteorology has issued a Severe Weather Warning for heavy rainfall for parts of the Kimberley District.

Elsewhere over the South Indian Ocean, Tropical Cyclone Grant was moving south-southeast of Diego Garcia.  At 10:00 a.m. EST on Tuesday the center of Tropical Cyclone Grant was located at latitude 14.8°S and longitude 75.1°E which put the center about 565 miles (910 km) south-southeast of Diego Garcia.  Grant was moving toward the west-southwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 950 mb.

Tropical Cyclone Hayley Rapidly Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Hayley rapidly intensified to the equivalent of a hurricane/typhoon northwest of Australia early on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Hayley was located at latitude 15.8°S and longitude 120.3°E which put the center about 210 miles (340 km) northwest of Broome, Australia.  Hayley was moving toward the southeast at 7 m.p.h. (11 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 976 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from north of Broome to Cockatoo Island.  The Warning included the Dampier Peninsula and Derby.

The Australia Bureau of Meteorology issued a Watch for the region from east of Derby to Kuri Bay.

Tropical Cyclone Hayley rapidly intensified to the equivalent of a hurricane/typhoon early on Monday.  The inner end of a rainband wrapped around the center of Hayley’s circulation.  A small eye with a diameter of 10 miles (16 km) formed at the center of Tropical Cyclone Hayley.  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 were revolving around the core of Hayley’s circulation.  Storms near the core 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 Hayley was very small.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Hayley’s circulation.  Winds to tropical storm force extended out 65 miles (105 km) from the center of Tropical Cyclone Hayley.

The Hurricane Intensity Index (HII) for Tropical Cyclone Hayley was 12.7.  The Hurricane Size Index (HSI) was 7.1 and the Hurricane Wind Intensity Size Index (HWISI) was 19.8.

Tropical Cyclone Hayley will move through an environment favorable for intensification during the next 12 hours.  Hayley will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of a small upper level ridge that is northwest of Australia.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Hayley is likely to continue to  intensify during the next 12 hours. Hayley could intensify rapidly because its circulation is so small.  Tropical Cyclone Hayley will move under the northeastern part of an upper level trough that is near the west coast of Australia in about 12 hours.  The upper level trough will produce northwesterly winds that will blow toward the top of Hayley’s circulation.  Those winds will cause the vertical wind shear to increase.  Tropical Cyclone Hayley will start to weaken when the vertical wind shear increases.

The upper level trough will steer Tropical Cyclone Hayley toward the east-southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Hayley will make landfall in the northern part of the Dampier Peninsula between Beagle Bay and Cape Leveque in 24 hours.

Tropical Cyclone Hayley is likely to be the equivalent of a hurricane/typhoon at the time of landfall.  Hayley will bring strong winds and heavy rain to the Dampier Peninsula and parts of Western Australia.  Heavy rain could cause flash floods in some locations.  Tropical Cyclone Hayley could also cause a storm surge of up to 10 feet (3 meters) along portions of the coast near where the center makes landfall.

Elsewhere over the South Indian Ocean, Tropical Cyclone Grant intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale southeast of Diego Garcia.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Grant was located at latitude 13.8°S and longitude 80.0°E which put the center about 710 miles (1145 km) southeast of Diego Garcia.  Grant was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 944 mb.

The Hurricane Intensity Index for Tropical Cyclone Grant was 28.3.  The Hurricane Size Index (HSI) was 10.4 and the Hurricane Wind Intensity Size Index (HWISI) was 38.7.  Tropical Cyclone Grant was similar in size and intensity to Hurricane Charley when Charley hit Southwest Florida in 2004.

Tropical Cyclone Grant Rapidly Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Grant rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean southeast of Diego Garcia on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Grant was located at latitude 13.6°S and longitude 82.0°E which put the center about 810 miles (1305 km) southeast of Diego Garcia.  Grant was moving toward the west-southwest at 12 m.p.h. (19 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 957 mb.

Tropical Cyclone Grant rapidly intensified to the equivalent of a major hurricane on Sunday.  The inner end of a rainband wrapped around the center of Grant’s circulation.  A small circular eye with a diameter of 10 miles (16 km) formed at the center of Tropical Cyclone Grant.  Bands of showers and thunderstorms were revolving around the center of Grant’s circulation.  Storms near the center of Grant 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 Grant was very small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Grant’s circulation.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Tropical Cyclone Grant.

Tropical Cyclone Grant will move through an environment favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°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 Grant is likely to continue to intensify during the next 24 hours unless the inner end of a rainband wraps around the existing eye and eyewall.  If concentric eyewalls form, then Grant will weaken.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will pass south of Diego Garcia in 48 hours.

Elsewhere over the South Indian Ocean, Tropical Cyclone Hayley was intensifying as it moved toward the coast of Western Australia.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Hayley was located at latitude 15.0°S and longitude 119.5°E which put the center about 290 miles (465 km) northwest of Broome, Australia.  Hayley was moving toward the south at 7 m.p.h. (11 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 988 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from north of Broome to Cape Leveque.

The Australian Bureau of Meteorology issued a Watch for the zone from Broome to Kuri Bay.  The Watch included Derby and Cockatoo Island.

 

Tropical Cyclone Hayley Forms Northwest of Australia

Tropical Cyclone Hayley formed over the South Indian Ocean northwest of Australia on Sunday. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Hayley was located at latitude 14.4°S and longitude 119.5°E which put the center about 320 miles (520 km) northwest of Broome, Australia.  Hayley was moving toward the south at 6 m.p.h. (10 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 993 mb.

A low pressure system over the South Indian Ocean strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Hayley.

The Australian Bureau of Meteorology issued a Watch for the portion of the coast of Western Australia from Broome to Cockatoo Island.  The Watch includes Derby.

A small low pressure system northwest of Australia strengthened to Tropical Cyclone Hayley.  Thunderstorms developed near the center of the low pressure system.  Thunderstorms also formed in bands in the western side of Hayley’s circulation.  Bands in the eastern side of Tropical Cyclone Hayley consisted primarily of showers and lower clouds.  Storms near the center of Hayley generated upper level divergence that pumped mass away to the west of the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Hayley was very small.  Winds to tropical storm force extended out 35 miles (55 km) from the center of Hayley’s circulation.

Tropical Cyclone Hayley will move through an environment favorable for intensification during the next 24 hours.  Hayley will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of a small upper level ridge that is northwest of Australia.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Hayley will intensify during the next 24 hours.  Hayley could intensify rapidly because its circulation is so small.  Tropical Cyclone Hayley is likely to strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Hayley will move around the western end of a high pressure system that is over northern Australia.  The high pressure system will steer Hayley toward the southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Hayley will move toward the coast of Western Australia.  Hayley is likely to reach the coast east of Broome in less than 48 hours.

Tropical Cyclone Hayley will bring strong winds and locally heavy rain to the coast of Western Australia east of Broome.  Heavy rain could cause flash floods in some locations.

Elsewhere over the South Indian Ocean, Tropical Cyclone Gran continued to intensify.  At 1:00 p.m. EST on Sunday the center of Tropical Cyclone Grant was located at latitude 13.3°S and longitude 83.5°E which put the center about 900 miles (1450 km) east-southeast of Diego Garcia.  Grant was moving toward the west-southwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 978 mb.

Tropical Cyclone Sean Continues to Weaken

Tropical Cyclone Sean continued to weaken steadily on Wednesday.  At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Sean was located at latitude 28.5°S and longitude 107.4°E which put the center about 440 miles (740 km) west of Geraldton, Australia.  Sean was moving toward the south-southeast at 4 m.p.h. (6 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 992 mb.

The effects of cooler Sea Surface Temperatures and strong vertical wind shear caused Tropical Cyclone Sean to continue to weaken on Wednesday.  An upper level trough over the South Indian Ocean west of Australia was producing strong northwesterly winds that were blowing across the top of Sean’s circulation.  Those winds were causing strong vertical wind shear.  The strong upper level winds also blew the tops off of thunderstorms that had been in the southeastern part of Tropical Cyclone Sean.  Bands revolving around the center of Sean’s circulation consisted primarily of showers and lower clouds.

Winds to tropical storm force extended out 130 miles (210 km) from the center of Tropical Cyclone Sean.

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

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

Tropical Cyclone Sean Weakens

Tropical Cyclone Sean weakened over the South Indian Ocean west of Australia on Tuesday.  At 10:00 a.m. EST on Tuesday the center of Tropical Cyclone Sean was located at latitude 26.7°S and longitude 107.3°E which put the center about 380 miles (610 km) west of Carnarvon, Australia.  Sean was moving toward the south-southwest at 16 m.p.h. (26 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 977 mb.

Tropical Cyclone Sean weakened on Tuesday as it moved over cooler water in the South Indian Ocean west of Australia.  An eye was no longer visible in the center of Sean’s circulation.  Thunderstorms were still occurring in bands in the southern and eastern parts of Tropical Cyclone Sean.  Bands in the northern and western parts of Sean’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Sean still produced some upper level divergence that pumped mass away to the southeast of the tropical cyclone.  The removal of mass in the upper levels of the atmosphere was less than the inflow of mass in the lower levels, which caused the surface pressure to increase.

The size of the circulation around Tropical Cyclone Sean increased even though Sean was weakening.  Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Sean’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Tropical Cyclone Sean.

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

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

Tropical Cyclone Sean Rapidly Intensifies to Equivalent of Major Hurricane

Tropical Cyclone Sean rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean west of Australia on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Sean was located at latitude 23.0°S and longitude 110.4°E which put the center about 210 miles (340 km) west of Exmouth, Australia.  Sean was moving toward the southwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 936 mb.

A Warning was in effect for the portion of the coast from Onslow to Ningaloo.  The Warning included Exmouth.

Tropical Cyclone Sean rapidly intensified to the equivalent of a major hurricane west of Australia on Monday.  A small circular eye with a diameter of 10 miles (16 km) was at the center of Sean’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 were revolving around the core of Tropical Cyclone Sean.  Storms near the core of Sean generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Tropical Cyclone Sean was relatively small.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Sean’s circulation.  Winds to tropical storm force extended out 110 miles (175 km) from the center of Tropical Cyclone Sean.

The Hurricane Intensity Index (HII) for Tropical Cyclone Sean was 25.1.  The Hurricane Size Index (HSI) was 12.6 and the Hurricane Wind Intensity Size Index (HWISI) was 37.7.  Tropical Cyclone Sean was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Tropical Cyclone Sean will move through an environment that will become unfavorable for intensification during the next 24 hours.  Sean will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the eastern part of an upper level trough over the South Indian Ocean.  The upper level trough will produce northwesterly winds are that will blow toward the top of Sean’s circulation.  Those winds will cause the vertical wind shear to increase.  The combination of cooler water and  more vertical wind shear will cause Tropical Cyclone Sean to weaken during the next 24 hours.

Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer Sean toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Sean will move a little farther away from the coast of Western Australia.

Bands in the eastern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause floods in some locations.  10.78 inches (274 mm) of rain has already fallen at the Karratha Airport.  4.37 inches (111 mm) of rain has already fallen at the Mardie Airport.

Flood Warnings were in effect for parts of the Pilbara and northern Gascoyne regions.  A Flood Warning was in effect for the Lyndon-Minilya Rivers. 

 

Tropical Cyclone Sean Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Sean intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday.  At 10:00 a.m. EST on Sunday the center of Tropical Cyclone Sean was located at latitude 20.5°S and longitude 113.9°E which put the center about 125 miles (200 km) north of Exmouth, Australia.   Sean 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 978 mb.

A Warning was in effect for the portion of the coast from Whim Creek to Ningaloo.  The Warning included Karratha, Damoier, Onslow, and Exmouth.

Tropical Cyclone Sea intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday.  A circular eye with a diameter of 17 miles (28 km) formed at the center of Sean’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 were revolving around the core of Tropical Cyclone Sean.  Storms near the core of Sean 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 Sean was relatively small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Sean’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Sean.

Tropical Cyclone Sean will move through an environment favorable for intensification during the next 24 hours.  Sean will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the northern part of an upper level ridge northwest of Australia.  The upper level ridge will produce easterly winds are that will blow toward the top of Sean’s circulation.  Those winds will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Sean will intensify during the next 24 hours.

Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer Sean toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Sean will move parallel to the coast of Western Australia.  The center of Sean is forecast to remain over water.

Bands in the southern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause flash floods in some locations.  3.74 inches (95 mm) of rain fell at the Lombadina Airstrip.

A Flood Watch was in effect for the coastal parts of the Kimberley and the Pilbara Districts.  Catchments likely to be affected include the West Kimberley Rivers, the De Grey River, the Pilbara Coastal Rivers, the Fortescue River, the Onslow Coast, and the Lyndon-Minilya Rivers.

Tropical Cyclone Sean Strengthens Near Western Australia

Tropical Cyclone Sean strengthened near the coast of Western Australia on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Sean was located at latitude 19.7°S and longitude 115.7°E which put the center about 120 miles (195 km) northwest of Karratha, Australia.  Sean was moving toward the west-southwest 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 987 mb.

A Warning was in effect for the portion of the coast from Whim Creek to Ningaloo.  The Warning included Karratha, Damoier, Onslow, and Exmouth.

A former Tropical Low near the coast of Western Australia strengthened on Saturday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Sean.  The inner end of a rainband wrapped around the western side of the center of Tropical Cyclone Sean.  A circular eye appeared to be forming at the center of Sean’s circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Sean.  Storms near the center of Sean generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass allowed the surface pressure to decrease.

The distribution of wind speeds around Tropical Cyclone Sean was relatively symmetrical.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Sean’s circulation.

Tropical Cyclone Sean will move through an environment favorable for intensification during the next 24 hours.  Sean will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the northern part of an upper level ridge northwest of Australia. The upper level ridge will produce easterly winds are that will blow toward the top of Sean’s circulation.  Those winds will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Sean will to intensify during the next 24 hours.  Sean could strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer Sean toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Sean will move parallel to the coast of Western Australia.  The center of Sean is forecast to remain over water.

Bands in the southern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Nat Moves Southwest of Tahiti

Tropical Cyclone Nat moved southwest of Tahiti on Wednesday. At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Nat was located at latitude 19.5°S and longitude 151.2°W which put it about 185 miles (300 km) southwest of Papeete, Tahiti. Nat was moving toward the southeast at 6 m.p.h. (10 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 998 mb.

Tropical Cyclone Nat brought rain showers and gusty winds to Tahiti on Wednesday. Nat started to weaken as it moved southwest of Tahiti. An upper level trough northeast of New Zealand produced strong westerly winds that blew across the top of Nat’s circulation. Those winds cause strong vertical wind shear. The strong upper level winds blew away the tops of many of the thunderstorms in Tropical Cyclone Nat. A few thunderstorms persisted in a band in the far eastern edge of Nat’s circulation. Other bands revolving around the center of Tropical Cyclone Nat consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 75 miles (120 km) from the center of Nat’s circulation.

Tropical Cyclone Nat will move through an environment unfavorable for intensification during the next 24 hours. Nat will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough northeast of New Zealand will continue to cause strong vertical wind shear. The strong vertical wind shear will cause Tropical Cyclone Nat to continue to weaken during the next 24 hours.

The upper level trough northeast of New Zealand will steer Tropical Cyclone Nat toward the east during the next 24 hours. On its anticipated track, the center of Tropical Cyclone Nat will pass south of Tahiti. Bands in the northern side of Nat will continue to bring gusty winds and rain showers to Tahiti during the next 24 hours.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Osai strengthened west of Palmerston Island. At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Osai was located at latitude 18.1°S and longitude 164.4°W which put it about 85 miles (135 km) west of Palmerston Island. Osai was moving toward the southeast at 18 m.p.h. (29 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 993 mb.