Tag Archives: SH06

Tropical Cyclone Phethai Forms Over Southwest Bay of Bengal

Tropical Cyclone Phethai formed over the southwest Bay of Bengal on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Phethai was located at latitude 11.1°N and longitude 84.5°E which put it about 480 miles (775 km) south-southeast of Visakhapatnam, India.  Phethai was moving toward the northwest at 5 m.p.h. (8 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.

More thunderstorms developed closer to the center of a low pressure system over the southwestern Bay of Bengal and the Indian Meteorological Department designated the system as Tropical Cyclone Phethai.  The distribution of thunderstorms was asymmetrical.  Most of the stronger thunderstorms were occurring northwest of the center of circulation.  There were fewer thunderstorms southeast of the center, although several bands of thunderstorms were developing on the eastern periphery of the circulation.  Storms northwest of the center were generating upper level divergence which was pumping mass away to the north of the tropical cyclone.

Tropical Cyclone Phethai will move through an environment somewhat favorable for intensification.  Phethai will move over water where the Sea Surface Temperature is near 27°C.  It will move around the eastern end of an upper level ridge over southeast Asia.  The ridge is already producing southeasterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear and the shear is the reason for the asymmetrical distribution of thunderstorms.  The wind shear will continue and it will inhibit the intensification of Tropical Cyclone Phethai.  Phethai could strengthen during the next 24 to 36 hours, but the rate of intensification is likely to be slow.

The ridge over southeast Asia will steer Tropical Cyclone Phethai north-northwest during the next several days.  On its anticipated track Phethai will move toward the east coast of India.  Tropical Cyclone Phethai could approach the coast near Visakhaptnam in about 48 hours.  Phethai will bring gusty winds but heavy rain and flooding will be greater risks.

Elsewhere, Tropical Cyclone 06S formed over the South Indian Ocean on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone 06S was located at latitude 9.1°S and longitude 91.2°E which put it about 1285 miles (2070 km) east of Diego Garcia.  It was moving toward the south-southeast at 3 m.p.h. (5 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 998 mb.

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.

Tropical Cyclone Berguitta Equivalent of a Major Hurricane

Tropical Cyclone Berguitta strengthened into the equivalent of a major hurricane on Monday as it moved over the South Indian Ocean.  At 4:00 p.m. EST on Monday the center of Tropical Cyclone Berguitta was located at latitude 18.1°S and longitude 62.4°E which put it about 375 miles (600 km) east-northeast of Port Louis, Mauritius.  Berguitta was moving toward the southwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed is 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 949 mb.

Tropical Cyclone Berguitta quickly intensified into the equivalent of a major hurricane on Monday.  A well formed circular eye developed at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in the ring.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  Storms near the center of Berguitta were generating upper level divergence which was pumping large quantities of mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extend out about 215 miles (345 km) from the center.

Tropical Cyclone Berguitta will move through an environment supportive of a strong tropical cyclone for several more days.  Berguitta will move over water where the Sea Surface Temperature is near 28°C.  It is moving through a region where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Berguitta is likely to maintain its intensity as the equivalent of a major hurricane and it could intensify further during the next day or two.

Tropical Cyclone Berguitta is moving near the western end of a subtropical ridge which is steering the tropical cyclone toward the southwest.  A general motion toward the southwest is forecast to continue for two or three more days.  On its anticipated track the center of Tropical Cyclone Berguitta could reach Mauritius within 48 hours.  Berguitta could reach La Reunion in less than 72 hours.

Tropical Cyclone Berguitta is a dangerous storm.  The Hurricane Intensity Index (HII) for Tropical Cyclone Berguitta is 20.6.  The Hurricane Size Index (HSI) is 14.1 and the Hurricane Wind Intensity Size Index (HWISI) is 34.7.  Those indices indicate that Tropical Cyclone Berguitta is capable of causing regional major damage.  Berguitta will bring strong winds and locally heavy rain to Mauritius and La Reunion.  The heavy rain is likely to cause flooding  and Berguitta could generate a storm surge at the coast.

Tropical Cyclone Berguitta Intensifies Into Equivalent of a Hurricane

Tropical Cyclone Berguitta intensified into the equivalent of a hurricane/typhoon on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Berguitta was located at latitude 17.8°S and longitude 63.1°E which put it about 415 miles (670 km) east-northeast of Port Louis, Mauritius.  Berguitta was nearly stationary.  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 985 mb.

The circulation of Tropical Cyclone Berguitta continued to get better organized on Sunday.  An eye appeared intermittently at the center of circulation.  The eye was surrounded by an elliptical ring of thunderstorms and the strongest winds were occurring in those storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storms near the center of Berguitta were generating upper level divergence which was pumping mass away from the center of circulation.

Tropical Cyclone Berguitta will continue to move through an environment favorable for intensification during the next several days.  Berguitta will move 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 Berguitta will continue to strengthen and it could intensify into the equivalent of a major hurricane.

Tropical Cyclone Berguitta is moving in a region where the steering winds are weak.  Berguitta moved little on Sunday.  A subtropical ridge south of Berguitta is forecast to steer the tropical cyclone slowly westward during the next 24 to 48 hours.  Berguitta will near the western end of the ridge in about two days and it is likely to move toward the southwest after that time.  On its anticipated track Tropical Cyclone Berguitta could reach Mauritius within 72 hours.

The core of Tropical Cyclone Berguitta could move very close to Mauritius and La Reunion.  Berguitta could be the equivalent of a major hurricane at that time.  It has the potential to cause major wind damage, a storm surge, heavy rain and floods.

Elsewhere over the South Indian Ocean microwave images of Invest 99S depicted a structure that looked very much like a tropical cyclone.  At 10:00 p.m. EST on Sunday the center of Invest 99S was centered at latitude 15.1°S and longitude 41.6°E which put it about 75 miles (120 km) east of Lumbo, Mozambique.  Microwave satellite images showed a clear area at the center of circulation surrounded by broken ring of showers and thunderstorms.  A primary rainband wrapped around the eastern side of the circulation and secondary bands of showers and thunderstorms existed in all quadrants of the circulation.  However, no official government agency is classifying the system as a tropical cyclone at the current time.

Tropical Cyclone Berguitta Strengthens Over South Indian Ocean

Tropical Cyclone Berguitta strengthened over the South Indian Ocean on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Berguitta was located at latitude 18.2°S and longitude 63.3°E which put it about 420 miles (675 km) east-northeast of Port Louis, Mauritius.  Berguitta was moving toward the west at 5 m.p.h. (8 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 994 mb.

The structure of Tropical Cyclone Berguitta organized quickly on Saturday.  An eye appeared on microwave satellite images of the center of circulation.  An elliptical ring of showers and thunderstorms surrounded the eye.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Berguitta.  There were more thunderstorms south and east of the center of circulation.  Storms near the core of Berguitta were generating upper level divergence which was pumping away mass.  The removal of mass allowed the surface pressure to decrease and the winds speeds to increase.

Tropical Cyclone Berguitta will be moving through an environment favorable for intensification during the next several days.  Berguitta will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Berguitta will likely intensify into the equivalent of a hurricane/typhoon during the next 24 hours.  It could intensify more rapidly once the eye and inner core become fully organized.

A subtropical ridge south of Berguitta is steering the tropical cyclone slowly toward the west.  A general motion toward the west is expected during the next day or two.  In about 48 hours Tropical Cyclone Berguitta will be closer to the western end of the ridge and it could start to move more toward the southwest.  On its anticipated track Tropical Cyclone Berguitta could approach Mauritius and La Reunion in three or four days.  Berguitta could be the equivalent of a hurricane/typhoon at that time.

Elsewhere in the southern hemisphere former Tropical Cyclone Joyce continued to drop locally heavy rain over parts of Western Australia.  At 10:00 p.m. EST on Saturday the center of former Tropical Cyclone Joyce was located at latitude 25.4°S and longitude 115.6°E which put it about 35 miles (55 km) southeast of Gascoyne Junction.  Former Tropical Cyclone Joyce was moving toward the west-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 998 mb.  The locally heavy rain was creating the potential for flooding in some locations.

Tropical Cyclone Alfred Develops Over Southwest Gulf of Carpentaria

More thunderstorms developed around the center of a tropical low on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Alfred.  At 7:00 p.m. EST on Sunday the center of Tropical Cyclone Alfred was located at latitude 15.4°S and longitude 137.2°E which put it about 75 miles (120 km) northeast of Borroloola, Australia.  Alfred was moving toward the south-southeast at 5 m.p.h. (8 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.

An area of low pressure organized over the southeastern Gulf of Carpentaria a few days ago.  The Tropical Low moved across the south coast of the Gulf of Carpentaria and then it moved westward over land.  The low turned north about 36 hours ago and it crossed into the southwest Gulf of Carpentaria on Sunday.  More thunderstorms developed closer to the center of circulation after the circulation moved over water.  Downdrafts in those storms transported stronger winds to the surface.  Upper level divergence pumped out mass and the surface pressure decreased.  When the low pressure system strengthened and acquired the necessary characteristics, the Australian Bureau of Meteorology classified it as Tropical Cyclone Alfred.

The low level circulation of Tropical Cyclone Alfred is well organized but the distribution of thunderstorms is very asymmetrical.  There is a well defined center of circulation that is over the extreme southwestern portion of the Gulf of Carpentaria.  However, most of the thunderstorms are developing southwest of the center of circulation.  Those thunderstorms are where the strongest winds are occurring.  There are few thunderstorms in the other portions of the core of the circulation.  There is one band of showers and thunderstorms farther away from the center on the eastern side of the circulation.

Tropical Cyclone Alfred will be moving through an environment that will be marginally favorable intensification.  It will be moving over water where the Sea Surface Temperature is near 31°C.  So, there is plenty of energy to support intensification.  An upper level ridge east of Alfred is producing northerly winds which are blowing over the top of the tropical cyclone.  Those winds are generating moderate wind shear, which is partially responsible for the asymmetrical distribution of thunderstorms.  In addition, the center is close to the coast and some of the circulation is passing over land.  Tropical Cyclone Alfred could intensify a little more before it gets to coast, but a weakening trend may be more likely.

A subtropical ridge is steering Tropical Cyclone Alfred toward the south-southeast and that general motion is expected to continue for another 12 to 24 hours.  On its anticipated track Tropical Cyclone Alfred could reach the coast near the border between the Northern Territory and Queensland in 12 to 18 hours.  Although Tropical Cyclone Alfred will bring some gusty winds, the greater hazard will be locally heavy rainfall.

Tropical Cyclone Ula Equivalent of Cat. 4 Hurricane

Tropical Cyclone continued to intensify steadily on Saturday and it is now the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  At 8:00 p.m. EDT on Saturday the center of Tropical Cyclone Ula was located at latitude 19.8°S and longitude 171.4°E which put it about 400 miles (640 km) east-northeast of Noumea, New Caledonia.  Ula was moving toward the southwest at 7 m.p.h. (11 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. (270 km/h).  The minimum surface pressure was 933 mb.

Tropical Cyclone Ula has circular eye with a diameter of 24 miles (38 km).  The eye is surrounded by a closed ring of thunderstorms.  Other spiral bands are rotating around the center of circulation.

Tropical Cyclone Ula is moving through an environment that is almost perfect for intensification.  The upper level winds are very light and there is almost no vertical wind shear.  Ula is over water where the Sea Surface Temperature (SST) is near 28°C.  It intensified quickly on Saturday and it has the potential to intensify a little more before it moves over cooler SSTs.

Tropical Cyclone Ula is moving around the western end of a subtropical ridge which is steering it toward the southwest.  That general motion is expected to continue for another 12 to 24 hours.  As Ula reaches the western end of the ridge it will start moving more toward the south.  Eventually the mid-latitude westerlies will start to steer Ula toward the southeast.

On its anticipated track Tropical Cyclone Ula could pass near the extreme southeastern islands of Vanuatu.  The greatest risk is to Aneityum and Futuna.  Ula could also bring wind and rain to Tanna, Aniwa, and Erromango.  The core with the strongest winds should pass southeast of Vanuatu, but Ula could bring wind and rain to some of those islands.  The center of Ula is expected to pass east of New Caledonia early next week, but it could also bring wind and rain to the Iles Loyaute.

Tropical Cyclone Ula Intensifies Rapidly, Threatens Vanuatu

Tropical Cyclone Ula intensified rapidly on Friday as it started to move toward Vanuatu.  At 4:00 p.m. EDT on Friday the center of Tropical Cyclone Ula was located at latitude 18.7°S and longitude 173.5°E which put it about 545 miles (880 km) east-northeast of Noumea, New Caledonia.  Ula was moving toward the southwest at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 95 m.p.h, (155 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 963 mb.

Tropical Cyclone Ula intensified rapidly on Friday because it was in a very favorable environment.  Satellite images showed that there is a 15 mile (24 km) wide eye at the center of Ula.  Additional spiral bands are rotating outside the core of the tropical cyclone.  Ula has a very symmetrical structure.  Thunderstorms in the core of Ula are creating upper level divergence, especially to the west of the center of circulation.

Tropical Cyclone Ula is in an environment favorable for further intensification.  It is over water where the Sea Surface Temperature is near 28°C.  An upper level ridge to the east of Ula is producing northeasterly winds over the top of the tropical cyclone.  However, the vertical wind shear is only modest and further intensification is possible.  Tropical Cyclone Ula could become the equivalent of a major hurricane during the weekend.

A subtropical ridge east of Ula is starting to steer the tropical cyclone toward the southwest.  That general motion is expected to continue for the next several days.  On its anticipated track Tropical Cyclone Ula could approach the southern islands of Vanuatu in about 48 hours.  It could be a very strong tropical cyclone when it nears those islands.