Tropical Storm Sanba Develops Near Palau

Tropical Storm Sanba developed near Palau on Sunday.  At 10:00 a.m. EST on Sunday the center of Tropical Storm Sanba was located at latitude 7.2°N and longitude 133.5°E which put it about 20 miles (35 km) south-southwest of Koror, Palau.  Sanba was moving toward the west at 19 m.p.h. (31 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 1000 mb.

Thunderstorms developed closer to the center of circulation of former Tropical Depression 02W and the Japan Meteorological Agency classified the system as Tropical Storm Sanba.  The distribution of storms was asymmetrical.  The stronger thunderstorms were occurring in bands west of the center of circulation.  The bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Sanba is moving south of a strong upper level ridge.  The ridge is producing easterly winds which are causing moderate vertical wind shear.  The wind shear is causing the asymmetrical distribution of thunderstorms.

Tropical Storm Sanba will move through an environment marginally favorable for intensification.  Sanba will move over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, the upper level ridge will continue to generate moderate vertical wind shear which will inhibit intensification.  Tropical Storm Sanba could get a little stronger during the next 24 to 36 hours.

The ridge is steering Tropical Storm Sanba toward the west and a general westerly motion is expected to continue.  On its anticipated track Tropical Storm Sanba could approach Mindanao in the southern Philippines in about 36 hours.  Sanba could bring gusty winds and locally heavy rain to parts of the southern Philippines.  Locally heavy rain could cause flash floods.

Tropical Cyclone Gita Strengthens Near Niue

Tropical Cyclone Gita strengthened on Saturday as it passed just to the east of Niue.  Outer rainbands on the western side of Gita were bringing gusty winds and heavy rain to Niue.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Gita was located at latitude 19.2°S and longitude 168.8°W which put it about 85 miles (135 km) east-southeast of Niue.  Gita was moving toward the south 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. (165 km/h).  The minimum surface pressure was 969 mb.  Tropical Cyclone Gita was the equivalent of a hurricane/typhoon.

The circulation of Tropical Cyclone Gita became more symmetrical on Saturday.  Several rainbands wrapped completely around the center of circulation.  A clear area appeared at the center of circulation on visible satellite images, which indicated that an eye was forming.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in the ring.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Other rainbands were revolving around the core of Tropical Cyclone Gita.

Tropical Cyclone Gita will move through an area favorable for intensification during the next 24 to 48 hours.  Gita will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone Gita is moving around the eastern end of an upper level low, but the upper level winds are weak and there is not much vertical wind shear.  There is drier air to the southwest of Gita, but it does not seem to be entering the circulation of the tropical cyclone.  Tropical Cyclone Gita will continue to intensify and it could strengthen rapidly.  Gita could strengthen into the equivalent of a major hurricane.

The upper level low is steering Tropical Cyclone Gita toward the south.  Gita will turn toward the southeast in about 12 to 24 hours.  When Gita reaches the southern side of the upper low, it will move toward the west.  On its anticipated track Tropical Cyclone Gita will pass just to the southeast of Niue.  Gita could approach Tonga in about 36 hours and it could the equivalent of a major hurricane at that time.

Tropical Cyclone Gita Forms Near Samoa

Tropical Cyclone Gita formed near Samoa on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Gita was located at latitude 14.8°N and longitude 172.3°E which put it about 155 miles (250 km) west of Pago Pago, Samoa.  Gita was moving toward the east at 18 m.p.h. (29 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 989 mb.

Tropical Cyclone Gita was bringing gusty winds and heavy rain to Samoa.  The strongest rainbands were north and east of the center of circulation.  The bands south of the center consisted primarily of showers and low clouds.  There appeared to be drier air in the southern half of the circulation which was inhibiting the development of taller clouds and stronger storms in that part of Gita.  Thunderstorms in the rainbands north of the center of circulation were generating upper level divergence which was pumping mass away to the east of the tropical cyclone.

Tropical Cyclone Gita will be moving through an environment favorable for intensification.  Gita will move over water where the Sea Surface Temperature is near 30°C.  An upper level low south of Gita is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear, but the shear does not appear to be strong enough to prevent intensification.  The drier air in southern half of the circulation will inhibit intensification.  However, if some of the rainbands north of the center wrap around the southern side of the center, then they could reduce the effects of the drier air.  Tropical Cyclone Gita is likely to intensify into the equivalent of a hurricane/typhoon during the weekend.

The upper low south of Gita is currently steering the tropical cyclone toward the east.  Gita will approach the eastern end of the upper low during the next 24 hours and it will move more toward the south.  Tropical cyclone Gita will turn back toward the west when it moves south of the upper low.  On its anticipated track Tropical Cyclone Gita will continue to bring gusty winds and heavy rain to Samoa for another 12 to 24 hours.  Gita could pass near Niue in 24 to 48 hours and it could move near Tonga in about three days.

Tropical Cyclone Cebile Meanders South of Diego Garcia

Tropical Cyclone Cebile has meandered south of Diego Garcia throughout this week.  At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Cebile was located at latitude 16.2°S and longitude 75.8°E which put it about 655 miles (1055 km) south-southeast of Diego Garcia.  Cebile was moving toward the southwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 949 mb.

Although it completed at least one eyewall replacement cycle, Tropical Cyclone Cebile maintains an impressive structure.  There is a circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several rainbands are revolving around the core of the circulation.  The storms in the core are generating upper level divergence which is pumping mass away.  Winds to hurricane/typhoon force extend out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extend out about 250 miles (400 km) from the center.

Tropical Cyclone Cebile remains in an environment favorable for strong tropical cyclones.  It is moving over water where the Sea Surface Temperature is generally near 28°C.  However, Cebile has moved slowly during the past several days and its circulation may have mixed cooler water to the surface in some locations.  The upper level winds are currently weak and there is little vertical wind shear.  Tropical Cyclone Cebile could maintain its intensity for another 24 to 36 hours unless it mixes more cool water to the surface.  An upper level trough approaching from the west will increase the vertical wind shear in a day or two and Cebile could weaken more quickly when that occurs.

Cebile is moving near the western end of a subtropical ridge which has been steering the tropical slowly toward the southwest.  The approaching upper level trough will begin to steer Tropical Cyclone Cebile more toward the southeast in a day or two.  On its anticipated track Tropical Cyclone Cebile is forecast to move farther away from Diego Garcia.

Tropical Cyclone Fehi Develops Near New Caledonia

Tropical Cyclone Fehi developed over the Coral Sea near New Caledonia on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Fehi was located at latitude 19.7°S and longitude 162.2°E which put it about 360 miles (580 km) northwest of Noumea, New Caledonia.  Fehi was moving toward the south-southeast at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 60 m.p.h. (90 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 982 mb.

The circulation of Tropical Cyclone Fehi was not well organized for much of Sunday, but it exhibited signs of greater organization in recent hours.  An upper level low near eastern Australia was producing strong northwesterly winds that were blowing over the top of the circulation.  Those winds caused strong vertical wind shear for much of Sunday, but the shear appeared to decrease on Sunday night.  A distinct low level center of circulation was exposed on recent visible satellite images.  Most of the thunderstorms were occurring in bands south of the center of circulation.  More bands of showers and low clouds seemed to be forming in the northern half of the circulation.  A rainband appeared to be wrapping around the northern side of the circulation.  There was some upper level divergence to the southeast of Tropical Cyclone Fehi.

Tropical Cyclone Fehi will be moving through an environment that will be marginally favorable for intensification during the next day or two.  Fehi is moving over water where the Sea Surface Temperature is near 28°C.  The upper level low will continue to cause vertical wind shear, but the shear may be small enough to allow for intensification.  Tropical Cyclone Fehi could intensify during the next 24 hours.  When Fehi moves farther south, it will move over much cooler water and the tropical cyclone will start to weaken.  Tropical Cyclone Fehi could make a transition to an extratropical cyclone in two or three days.

The upper low near eastern Australia is steering Tropical Cyclone Fehi toward the south-southeast.  A general motion toward the southeast is expected during the next two or three days.  On its anticipated track the center of Tropical Cyclone Fehi is forecast to pass west of New Caledonia.  Although the center is likely to pass to the west of New Caledonia, rainbands on the eastern side of Fehi could bring gusty winds and locally heavy rain.  Heavy could cause flash floods.  Tropical Cyclone Fehi could approach New Zealand in about three days.  Fehi could be a strong extratropical cyclone at that time.

Tropical Cyclone Cebile Intensifies Rapidly Into Equivalent of Major Hurricane

Tropical Cyclone Cebile intensified rapidly on Sunday from a tropical storm to the equivalent of a major hurricane over the South Indian Ocean.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Cebile was located at latitude 14.5°S and longitude 82.5°E which put it about 850 miles (1375 km) southeast of Diego Garcia.  Cebile was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 945 mb.

Tropical Cyclone Cebile intensified very rapidly during the past 24 hours as it moved through a very favorable environment.  The maximum sustained wind speed increased from 50 m.p.h. (80 km/h) to 130 m.p.h. (215 km/h).  The circulation of Tropical Cyclone Cebile is very well organized.  There is a circular eye at the center of circulation.  The eye is surround by a ring of strong thunderstorms and the strongest winds are occurring in the ring of storms.  Rainbands are revolving around the core of the circulation.  Tropical Cyclone Cebile is generating strong upper level divergence which is pumping away mass and allowing the surface pressure to decrease rapidly.

The circulation of Tropical Cyclone Cebile is symmetrical.  Winds to hurricane/typhoon force extend out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extend out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Cebile is 25.1.  The Hurricane Size Index (HSI) is 12.7 and the Hurricane Wind Intensity Size Index (HWISI) is 37.8.

Tropical Cyclone Cebile continues to move through an environment favorable for intensification.  Cebile is moving over water where the Sea Surface Temperature is near 28°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Cebile is likely to intensify further and it could become the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Cebile is moving near the western part of a subtropical ridge which is steering the tropical cyclone toward the southwest.  A general southwesterly motion is expected to continue for the next few days.  On its anticipated track Tropical Cyclone Cebile will remain well south of Diego Garcia.

Elsewhere in the tropics, Tropical Cyclone 08S was moving near the northern end of New Caledonia.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone 08S was located at latitude 18.8°S and longitude 162.1°E which put it about 370 miles (600 km) northwest of Noumea, New Caledonia.  It was moving toward the southeast at 11 m.p.h. (17 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 986 mb.

Tropical Cyclone Cebile Forms East of Diego Garcia

After a relatively quiet week in the tropics Tropical Cyclone Cebile formed east of Diego Garcia on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Cebile was located at latitude 12.1°S and longitude 84.2°E which put it about 870 miles (1405 km) east-southeast of Diego Garcia.  Cebile was moving toward the southwest 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 998 mb.

Tropical Cyclone Cebile organized rapidly on Saturday.  A primary rainband wrapped most of the way around the center of circulation and an elliptical eye appeared to be developing at the center.  Other bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Cebile.  There were more thunderstorms in the western half of the circulation, but there were rainbands in all quadrants of Cebile.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  The removal of mass was causing the surface pressure to decrease and the wind speed to increase.

Tropical Cyclone Cebile will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 28°C.  Cebile is moving just to the north of the axis of a subtropical ridge that runs east to west across the Southern Indian Ocean.  The northern half of the ridge is producing easterly winds which are blowing toward the top of the circulation, but the vertical wind shear is not too strong.  A combination of warm water and minimal vertical wind shear will allow Tropical Cyclone Cebile to strengthen and it could intensify rapidly.  Cebile is likely to strengthen into the equivalent of a hurricane/typhoon during the next day or two.  Tropical Cyclone Cebile could intensify into the equivalent of a major hurricane during the next week.

The subtropical ridge is steering Tropical Cyclone Cebile toward the southwest and that general motion is expected to continue for several more days.  On its anticipated track Tropical Cyclone Cebile is expected to move southeast of Diego Garcia.

Tropical Cyclone Berguitta Speeds Past La Reunion

Tropical Cyclone Berguitta sped past La Reunion on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Berguitta was located at latitude 22.8°S and longitude 54.3°E which put it about 70 miles (110 km) southwest of La Reunion.  Berguitta was moving toward the west-southwest at 22 m.p.h. (35 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 982 mb.

Tropical Cyclone Berguitta was the equivalent of a hurricane/typhoon when it moved past La Reunion.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of circulation.  So, parts of La Reunion may have experienced winds to hurricane/typhoon force.  Winds to tropical storm force extended out about 230 miles (370 km) from the center.  Winds to tropical storm force would have occurred over all of La Reunion.  Berguitta also dropped locally heavy rain over La Reunion and flooding is a possibility.

Tropical Cyclone Berguitta will move into an environment that will become increasingly less favorable for a tropical cyclone as it moves away from La Reunion.  Berguitta is moving over water where the Sea Surface Temperature is near 26°C, but it will move over colder water when it moves farther south.  An upper level trough west of Madagascar will produce northwesterly winds which will increase the vertical wind shear.  A combination of colder water and increased shear will slowly weaken Tropical Cyclone Berguitta.  Berguitta will likely make a transition to an extratropical cyclone during the weekend.

Berguitta is moving around the western end of a subtropical ridge, which is steering the tropical cyclone toward the southwest.  It is expected to continue to move toward the southwest for another day or so.  At that time Berguitta will move around the western end of the ridge and it will move more toward the south.  On its anticipated track the center of Tropical Cyclone Berguitta is expected move steadily away from La Reunion.  Berguitta is forecast to stay east of Madagascar.  Weather conditions on La Reunion should gradually improve as Tropical Cyclone Berguitta moves away.

Tropical Cyclone Berguitta Brings Wind, Rain to Mauritius & La Reunion

Tropical Cyclone Berguitta was bringing wind and rain to Mauritius and La Reunion late Wednesday as it closed in on those places.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Berguitta was located at latitude 20.1°S and longitude 58.0°E which put it about 80 miles (130 km) east-northeast of Port Louis, Mauritius.  Berguitta was moving toward the southwest at 13 m.p.h. (21 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 979 mb.

Tropical Cyclone Berguitta was the equivalent of a hurricane/typhoon as it approached Mauritius and La Reunion.  A partial eyewall surrounded the remnant of the eye.  A primary rainband wrapped around the western side of the circulation.  The heaviest rain was falling in the rainband.  Numerous bands of showers and isolated thunderstorms were revolving around the core of the circulation.  Tropical Cyclone Berguitta was still generating upper level divergence which was pumping mass away from the center of circulation.  Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 195 miles (315 km) from the center.

Tropical Cyclone Berguitta was moving through an environment that could allow it to maintain its intensity for another 24 to 36 hours.  Berguitta will move over water where the Sea Surface Temperature is near 27°C.  An upper level ridge to the east of Berguitta is producing easterly winds which are blowing toward the top of the tropical cyclone.  Those winds are causing moderate vertical wind shear, but they may not be strong enough to weaken the storm during the next 24 hours.

Tropical Cyclone Berguitta is moving around the western end of a subtropical ridge which is steering the tropical cyclone toward the southwest.  A general southwesterly motion is expected to continue for another day or two.  On its anticipated track the center of Tropical Cyclone Berguitta will reach Mauritius within six hours.  The center of Berguitta will be near La Reunion in 12 to 14 hours.

Tropical Cyclone Berguitta will bring strong, gusty winds to Mauritius and La Reunion on Thursday.  It could be the equivalent of a hurricane/typhoon when it moves over those places.  The center could pass right over Mauritius and the winds to hurricane/typhoon force could blow over it.  The center could pass just to the east of La Reunion, but winds to hurricane/typhoon force could also blow across it.  Berguitta will also drop locally heavy rain which could cause floods.  The winds could cause a storm surge of 5 to 8 feet (1.5 to 1.5 meters) on the eastern shores where the winds will be blowing water toward the coast.

Tropical Cyclone Berguitta Moves Closer to Mauritius

Tropical Cyclone Berguitta moved closer to Mauritius and La Reunion on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Berguitta was located at latitude 18.4°S and longitude 60.3°E which put it about 250 miles (400 km) east-northeast of Port Louis, Mauritius.  Berguitta was moving toward the southwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 973 mb.

Tropical Cyclone Berguitta weakened a little on Tuesday but it remained a dangerous tropical cyclone.  An upper level ridge southeast of Berguitta produced easterly winds which caused some vertical wind shear over the tropical cyclone.  Satellite imagery also suggested that Berguitta could have gone through an eyewall replacement cycle.  The combination of increased wind shear and a possible eyewall replacement cycle altered the structure of Berguitta.  Microwave satellite images intermittently indicated the presence of an eye at the center of circulation.  However, almost all of the stronger thunderstorms were occurring west of the center of circulation.  The bands in the eastern half of the circulation consisted primarily of low clouds and showers.  The increased shear probably caused the asymmetrical distribution of storms.

Berguitta will move through an environment supportive of a tropical cyclone during the next 24 hours.  It will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will continue to produce vertical wind shear.  The wind shear will likely prevent Berguitta from intensifying significantly.  Tropical Cyclone Berguitta is forecast to weaken slowly during the next 24 hours, but it could maintain most of its intensity, since it is still over warm water.

Tropical Cyclone Berguitta is moving around the western end of a subtropical ridge which is steering the tropical cyclone toward the southwest.  A general southwesterly motion is forecast to continue for another day or two.  On its anticipated track the center of Tropical Cyclone Berguitta could reach Mauritius in 24 hours.  Berguitta is likely to be the equivalent of a hurricane/typhoon when it reaches Mauritius.  It will bring strong winds and locally heavy rain.  Heavy rain could cause serious flooding.  The strong winds could generate a storm surge of 4 to 7 feet (1 to 2 meters) at the coast.  Tropical Cyclone Berguitta could reach La Reunion within 36 hours.