Tropical Cyclone Joaninha Develops Over Southwest Indian Ocean

Tropical Cyclone Joaninha developed over the Southwest Indian Ocean on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Joaninha was located at latitude 15.7°S and longitude 62.2°E which put it about 260 miles (420 km) north-northwest of Rodrigues, Mauritius.  Joaninha was moving toward the south at 7 m.p.h. (11 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 992 mb.

More thunderstorms developed near the center of a low pressure system over the Southwest Indian Ocean on Friday and the system was designated Tropical Cyclone Joaninha.  The inner end of a band of showers and thunderstorms wrapped around the eastern and southern sides of the center of circulation.  However, the distribution of thunderstorms around Joaninha was asymmetrical.  Several bands of thunderstorms developed in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Thunderstorms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 150 miles (240 km) from the center of circulation.

Tropical Cyclone Joaninha will move through an environment favorable for intensification during the next several days.  Joaninha will move over water where the Sea Surface Temperature is 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 Joaninha will continue to intensify during the next 48 to 72 hours.  Joaninha could strengthen into the equivalent of a hurricane/typhoon within 24 hours.  It could be the equivalent of a major hurricane in 48 to 72 hours.

Tropical Cyclone Joaninha will move around the western end of a ridge of high pressure.  The ridge will steer Joaninha toward the south for another day or so.  After it rounds the western end of the ridge, Tropical Cyclone Joaninha will move more toward the southeast.  On its anticipated track Joaninha could approach Rodrigues in about 72 hours.  It could be the equivalent of a major hurricane at that time.

Tropical Cyclones Trevor and Veronica Bracket Australia

Tropical Cyclones Trevor and Veronica bracketed Australia on Thursday night.  Tropical Cyclone Veronica was stronger but Tropical Cyclone Trevor was the more immediate threat.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Trevor was located at latitude 14.6°S and longitude 139.4°E which put it about 200 miles (320 km) east-northeast of Port McArthur, Australia.  Trevor was moving toward the southwest at 8 m.p.h. (13 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. (170 km/h).  The minimum surface pressure was 967 mb.  A Tropical Cyclone Warning was in effect for the portion of the coast from Cape Shield, Northern Territory to Karumba, Queensland.

Tropical Cyclone Trevor strengthened more quickly as more of the circulation moved over the Gulf of Carpentaria.  A circular eye formed at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of Trevor generated upper level divergence which pumped mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core.  Winds to hurricane/typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 130 miles (210 km) from the center.

Tropical Cyclone Trevor will move through an environment favorable for intensification for about another 24 hours.  Trevor will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Trevor will continue to intensify on Friday and it could strengthen into the equivalent of a major hurricane.

Tropical Cyclone Trevor will move around the northwestern side of a subtropical ridge.  The ridge will steer Trevor toward the southwest.  On its anticipated track Tropical Cyclone Trevor will make landfall near Port McArthur in about 24 hours.  Trevor could be a major hurricane at that time.  It will bring strong winds, which could cause a significant storm surge at the coast.  Tropical Cyclone Trevor will drop heavy rain when it moves inland and it could cause flooding in some locations.

At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Veronica was located at latitude 17.8°S and longitude 116.7°E which put it about 200 miles (355 km) north-northwest of Port Hedland, Australia.  Veronica was moving toward the southwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 941 mb.  A Tropical Cyclone Warning was in effect for the portion of the coast from Pardoo to Mardie including Port Hedland and Karratha.

Tropical Cyclone Veronica remains the equivalent of a major hurricane.  A circular eye was surrounded by a ring of strong storms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Veronica.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

Tropical Storm Veronica will remain in an area favorable for intensification for another 24 to 36 hours.  Veronica will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Veronica could strengthen on Friday.

Tropical Cyclone will move around the western end of a ridge of high pressure.  Veronica will move toward the south-southeast after it rounds the end of the ridge.  On its anticipated track Tropical Cyclone Veronica could make landfall on the coast of Western Australia between Karratha and Port Hedland in about 48 hours.  Veronica is likely to be the equivalent of a major hurricane at that time.

Tropical Cyclones Veronica and Trevor Threaten Australia

Tropical Cyclones Veronica and Trevor posed threats to Australia on Wednesday night.  Tropical Cyclone Veronica intensified very rapidly into the equivalent of a major hurricane on Wednesday off the coast of Western Australia.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Veronica was located at latitude 16.5°S and longitude 117.6°E which put it about 275 miles (445 km) north-northwest of Port Hedland, Australia.  Veronica was moving toward the south-southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 929 mb.  A Tropical Cyclone Watch was in effect for the portion of the coast from Pardoo to Mardie including Port Hedland and Karratha.

Tropical Cyclone Veronica intensified very rapidly during the past 24 hours.  Veronica strengthened from the equivalent of a tropical storm to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  A small pinhole eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Veronica had a large circulation.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Veronica was 29.8.  The Hurricane Size Index (HSI) was 18.6 and the Hurricane Wind Intensity Size Index (HWISI) was 48.4.

Tropical Cyclone Veronica will remain in an environment favorable for strong tropical cyclones for several more days.  Veronica will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Veronica could strengthen into the equivalent of a Category 5 hurricane during the next 24 hours.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause fluctuations in the intensity of Veronica.

Tropical Cyclone Veronica will move around the western end of a subtropical ridge.  The ridge will steer Veronica toward the south-southwest.  Tropical Cyclone Veronica could move toward the south-southeast after it rounds the western end of the ridge.  On its anticipated track Tropical Cyclone Veronica could approach the coast of Western Australia in about three days.  Veronica could be the equivalent of a major hurricane at that time.

Tropical Cyclone Trevor moved over the eastern Gulf of Carpentaria on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Trevor was located at latitude 13.1°S and longitude 141.1°E which put it about 55 miles (90 km) southwest of Weipa, Australia.  Trevor was moving toward the southwest at 2 m.p.h. (3 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 minium surface pressure was 988 mb.  A Tropical Cyclone Watch was in effect for the coast from Nhulunbuy to Karumba.

The circulation of Tropical Cyclone Trevor was gradually reorganizing as the center moved farther into the Gulf of Carpentaria.  Trevor will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Trevor will intensify during the next 48 hours and it could strengthen into the equivalent of a major hurricane.  On its anticipated track Trevor is forecast to approach the southwest of the Gulf of Carpentaria near Port McArthur in about 48 hours.

Tropical Cyclone Trevor Brings Wind and Rain to Northern Queensland

Tropical Cyclone Trevor brought wind and rain to northern Queensland on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Trevor was located at latitude 13.1°S and longitude 141.9°E which put it about 35 miles (55 km) south of Weipa, Australia.  Trevor was moving toward the west at 6 m.p.h. (10 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 973 mb.

A Tropical Cyclone Warning remained in effect for the west coast of the Cape York Peninsula from Cape York to Pormpuraaw.  The Australian Bureau of Meteorology issued a Tropical Cyclone Watch for the east coast of the Northern Territory from Nhulunbuy to the border between the Northern Territory and Queensland.

Tropical Cyclone Trevor made landfall on the east coast of the Cape York Peninsula near Lockhart River on Tuesday.  Trevor was the equivalent of a major hurricane when it made landfall.  Tropical Cyclone Trevor moved slowly westward across the peninsula to a position south of Weipa.  Trevor brought strong gusty winds and dropped locally heavy rain over the Cape York Peninsula.

Tropical Cyclone Trevor weakened steadily while it move over land.  The eye filled with lower clouds and the number of strong thunderstorms around the core and in the rainbands decreased.  However, the circulation remained intact.  Tropical Cyclone Trevor retained a well defined low level circulation with a distinct tight center.

The center of Tropical Cyclone Trevor will move over the eastern Gulf of Carpentaria in a few hours.  Trevor will move through an environment very favorable for intensification during the next several days.  It will move over water where the Sea Surface Temperature is near 31°C.  Tropical Cyclone Trevor will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Trevor is likely to intensify when it moves back over water.  It could intensify rapidly once an eye and an eyewall redevelop at the core of the circulation.  Tropical Cyclone Trevor could strengthen into the equivalent of a major hurricane within 48 hours.

Tropical Cyclone Trevor will move around the northwestern part of a subtropical ridge.  The ridge will continue to steer Trevor toward the west for another day or so.  After that time Tropical Cyclone Trevor will move more toward the west-southwest.  On its anticipated track Trevor could reach the east coast of the Northern Territory in about 72 hours.  It is likely to be the equivalent of a major hurricane at that time.

Elsewhere, Tropical Cyclone Veronica developed quickly off the coast of Western Australia on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Veronica was located at latitude 15.0°S and longitude 119.5°E which put it about 630 miles (1015 km) northeast of Learmonth, Australia.  Veronica was moving toward the west-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 990 mb.  Tropical Cyclone Veronica is also forecast to strengthen into the equivalent of a major hurricane and it could approach the coast of Western Australia in about four days.

Rapidly Intensifying Tropical Cyclone Trevor Nears Cape York Peninsula

Rapidly intensifying Tropical Cyclone Trevor neared the Cape York Peninsula on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Trevor was located at latitude 13.0°S and longitude 144.3°E which put it about 80 miles (130 km) east of Lockhart River, Australia.  Trevor was moving toward the west-southwest at 5 m.p.h. (8 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 955 mb.

The Australian Bureau of Meteorology issued Tropical Cyclone Warnings for the portion of the east coast of the Cape York Peninsula from Orford Ness to Cape Flattery, from Mapoon to Pormpuraaw on the west coast of the peninsula and for inland locations between the two coasts.

Tropical Cyclone Trevor rapidly intensified into the equivalent of a hurricane/typhoon on Monday.  An eye with a diameter of 15 miles (24 km) developed at the center of circulation.  The eye was surround by a ring of strong 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 Trevor.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

The circulation around Tropical Cyclone Trevor was relatively small.  Winds to hurricane/typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 90 miles (145 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Trevor was 17.8.  The Hurricane Size Index (HSI) was 11.0 and the Hurricane Wind Intensity Size Index (HWISI) was 28.8.

Tropical Cyclone Trevor will remain in an environment favorable for intensification for another 12 hours until it makes landfall.  Trevor will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Trevor could intensify into the equivalent of a major hurricane before it makes landfall.  It will take Trevor about 24 hours to cross the Cape York Peninsula.  Tropical Cyclone Trevor will weaken during that time.  Trevor will emerge over the Gulf of Carpentaria in about 36 hours and it will strengthen again after it gets back over water.

Tropical Cyclone Trevor will move around the northwestern portion of a subtropical ridge.  The ridge will steer Trevor toward the west-southwest.  On its anticipated track Tropical Cyclone Trevor will make landfall near or just to the south of Lockhart River in about 12 hours.    Trevor is forecast to move westward across the Cape York Peninsula.  it is likely to emerge over the Gulf of Carpentaria between Weipa and Aurukun in about 36 hours.  Tropical Cyclone Trevor will be capable of causing major damage.  It will bring strong winds and a storm surge to the area around Lockhart River.  Trevor will drop locally heavy rain over parts of the Cape York Peninsula and flooding could occur in some locations.  Tropical Cyclone Trevor could threaten the Northern Territory of Australia later this week.

Tropical Cyclone Trevor Develops Over Coral Sea

Tropical Cyclone Trevor developed over the Coral Sea on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Trevor was located at latitude 13.2°S and longitude 146.1°E which put it about 190 miles (305 km) east of Lockhart River, Australia.  Trevor was moving toward the south-southwest at 10 m.p.h. (16 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 956 mb.

The circulation around a low pressure system over the Coral Sea organized quickly on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Trevor.  An inner rainband wrapped around the center of circulation and there were indications that an eye could be starting to form.  Bands of showers and thunderstorms were developing in all parts of the Tropical Cyclone Trevor and the circulation was symmetrical.  Storms near the center of Trevor were generating upper level divergence which was pumping mass away from the tropical cyclone in all directions.

Tropical Cyclone Trevor will move through an environment favorable for intensification during the next 24 to 36 hours.  Trevor will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Trevor will intensify during the next day or so and it could intensify rapidly.  It is likely to strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Trevor will move around the northwestern portion of a subtropical ridge.  The ridge will steer Trevor toward the west-southwest.  On its anticipated track Tropical Cyclone Trevor could reach the east coast of the Cape York peninsula in about 36 hours.  Trevor could be the equivalent of a hurricane/typhoon by that time.

The Australian Bureau of Meteorology has issued a Tropical Cyclone Warning for the portion of the coast from Cape Grenville to Cape Flattery.  Tropical Cyclone Watches are in effect for the portions of the coast from Cape York to Cape Grenville and from Cape Flattery to Cape Tribulation.

Tropical Cyclone Idai Drops Heavy Rain on Mozambique and Zimbabwe

Tropical Cyclone Idai dropped heavy rain on parts of Mozambique and Zimbabwe on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Idai was located at latitude 19.0°S and longitude 32.5°E which put it about 50 miles (80 km) southwest of Mutare, Zimbabwe.  Idai was moving toward the west-northwest 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 985 mb.

Although the wind speeds around Tropical Cyclone Idai decreased steadily on Friday, the circulation remained very well organized.  An inner rainband wrapped most of the way around a well defined center of circulation.  Bands of showers and thunderstorms were revolving around the center of Idai.  The strongest bands were occurring in the southern half of the circulation.  Storms near the core of the circulation were still generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Idai dropped heavy rain from the coast of central Mozambique near Beira where Idai caused significant damage westward to the eastern Zimbabwe.  Persistent heavy rain was likely causing flooding along some of the rivers in central Mozambique and eastern Zimbabwe.  Tropical Cyclone Idai is forecast to continue to move toward the west-northwest and heavy rain is likely to spread over more of Zimbabwe.

Tropical Cyclone Idai Makes Landfall in Mozambique

Strong Tropical Cyclone Idai made landfall in Mozambique very close to Beira on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Idai was located at latitude 19.4°S and longitude 34.5°E which put it about 30 miles (50 km) northwest of Beira, Mozambique.  Idai was moving toward the west at 8 m.p.h. (13 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 958 mb.

The core of Tropical Cyclone Idai moved directly over Beira, Mozambique.  The eye moved over Beira.  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h) at the time of landfall.  Winds to hurricane/typhoon force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles from the center of Tropical Cyclone Idai.

The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 19.2 at the time of landfall.  The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 33.0.  Tropical Cyclone Idai was capable of causing very serious wind damage.  Both sides of the eyewall which contained the strongest winds moved over Beira.  The relatively slow rate at which Idai was moving would have resulted in a prolonged period of strong winds, which would have increased the potential for damage.

Clockwise rotation around Tropical Cyclone Idai would have produced strong southerly winds when Idai approached Beira.  Those winds would have pushed water into the mouth of the Rio Pungoe which is on the western side of Beria.  There could have been an enhanced storm surge of 12 to 18 feet (4 to 6 meters) in that area.  Beira is one of the largest cities in Mozambique and it has a population of over half a million people.  Idai could have cause very serious damage around Beira.

Tropical Cyclone Idai will move toward the west-northwest during the next day or two.  On its anticipated track Idai will move farther inland over Mozambique and it will eventually move over Zimbabwe.  Tropical Cyclone Idai will weaken steadily as it moves inland, but it will drop heavy rain over central Mozambique and over parts of Zimbabwe.  The heavy rain could cause flooding along portions of Rio Pungoe and Rio Buzi as well as other parts of central Mozambique and Zimbabwe.

Major Tropical Cyclone Idai Nears Mozambique

Major Tropical Cyclone Idai neared the coast of Mozambique on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Idai was located at latitude 19.7°S and longitude 37.5°E which put it about 170 miles (275 km) east of Beira, Mozambique.  Idai was moving toward the west-southwest at 7 m.p.h. (11 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 949 mb.

Tropical Cyclone Idai strengthened back into the equivalent of a major hurricane after it completed an eyewall replacement cycle on Wednesday.  An eye with a diameter of 35 miles (55 km) appeared on satellite images after the remnants of the original inner eyewall weakened.  A ring of strong thunderstorms surrounded the large eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Idai.  Storms near the core of Idai were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The size of the circulation around Tropical Cyclone Idai increased during the eyewall replacement cycle.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 22.1.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 38.6.

Tropical Cyclone Idai will remain in an environment favorable for intensification until it reaches the coast of Mozambique.  Idai will move over water where the Sea Surface Temperature is near 30°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  Idai could strengthen before it reaches the coast.

Tropical Cyclone Idai will move north of a subtropical ridge over southern Africa.  The ridge will steer Idai toward the west.  On its anticipated track Tropical Cyclone Idai will make landfall on the coast of Mozambique near Beira in less than 24 hours.  Idai will bring very strong winds and it will be capable of causing regional major damage.  Tropical Cyclone Idai will also drop heavy rain over parts of Mozambique and it will likely cause flooding in some locations.

Tropical Cyclone Savannah Forms North of Cocos Island

Tropical Cyclone Savannah formed over the southeast Indian Ocean north of Cocos Island on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Savannah was located at latitude 11.3°S and longitude 96.7°E which put it about 60 miles (100 km) north of Cocos Island.  Savannah was moving toward the south-southwest at 8 m.p.h. (13 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 997 mb.  The Australian Bureau of Meteorology has issued a Tropical Storm Warning for Cocos Island.

More thunderstorms formed near an area of low pressure over the southeastern Indian Ocean west of Australia and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Savannah.  The distribution of thunderstorms around Savannah was asymmetrical.  Several bands of showers and thunderstorms developed in the western half of the circulation.  Rainbands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Tropical Cyclone Savannah was moving south of an upper level ridge.  The ridge was generating easterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.

Tropical Cyclone Savannah will move through an environment favorable for intensification during the next several days.  Savannah will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will continue to cause vertical wind shear, but the shear could decrease during the next 48 hours.  Tropical Cyclone Savannah is likely to intensify during the next day or two.

Tropical Cyclone Savannah will move near the western end of a strengthening subtropical ridge over Australia.  The ridge will steer Savannah toward the south-southwest during the next day or two.  On its anticipated track Tropical Cyclone Savannah will bring gusty winds and locally heavy rain to Cocos Island during the next 24 hours.