Tag Archives: La Reunion

Tropical Cyclone Herold Brings Wind, Rain to Rodrigues

Tropical Cyclone Herold brought wind and rain to Rodrigues on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Herold was located at latitude 21.4°S and longitude 64.1°E which put it about 125 miles (200 km) south-southeast of Port Mathurin, Mauritius.  Herold was moving toward the southeast at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 978 mb.

The core of Tropical Cyclone Herold passed west of Rodrigues on Tuesday, but it came close enough to that island to bring gusty winds and locally heavy rain.  A weather station at the Plaine Corail airport on Rodrigues reported a wind gust of 80 m.p.h. (130 km/h).

Although Tropical Cyclone Herold began to weaken on Tuesday.  It remained strong enough to generate wind gusts to hurricane/typhoon force over parts of Rodrigues.  Microwave satellite imagery indicated the there was still an eye at the center of Herold, although the eye was not evident on conventional infrared images.  The eye was surround by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.

Tropical Cyclone Herold will continue to weaken during the next several days.  An upper level trough near Madagascar and an upper level ridge over the South Indian Ocean will interact to produce strong northwesterly winds which will blow toward the top of Herold.  Those winds will cause strong vertical wind shear and they will cause the tropical cyclone to weaken.

The upper level trough and ridge will steer Tropical Cyclone Herold toward the southeast.  On its anticipated track Herold will move quickly away from Rodrigues.  Weather conditions on that island will gradually improve as Tropical Cyclone Herold moves farther away.

Tropical Cyclone Herold Passes North of Mauritius

Tropical Cyclone Herold passed north of Mauritius on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Herold was located at latitude 17.3°S and longitude 57.6°E which put it about 230 miles (370 km) north of Port Louis, Mauritius.  Herold was moving toward the east-southeast at 20 m.p.h. (32 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 972 mb.

The circulation around Tropical Cyclone Herold remained well organized on Monday.  Microwave satellite imagery indicated that there was an eye at the center of circulation, but the eye was not visible on conventional satellite images.  The eye was surround by a narrow 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 Herold.  Many of the stronger thunderstorms were in bands south and east of the center of circulation.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center.  Winds to tropical storm force extended out 130 miles (215 km) from the center of circulation.

Tropical Cyclone Herold may have reached its maximum intensity.  Herold will move over water where the Sea Surface Temperature is near 28°C.  So, there will be plenty of energy in the upper layer of the South Indian Ocean to support intensification.  However, an upper level trough near Madagascar and an upper level ridge over the South Indian Ocean will interact to produce strong northwesterly winds which will blow toward the top of Tropical Cyclone Herold.  Those winds will cause moderate vertical wind shear and they will likely prevent further intensification.  In fact the wind shear is likely to be strong enough to cause Herold to start to weaken during the next 24 hours.

The upper level trough and ridge will combine to steer Tropical Cyclone Herold quickly toward the east-southeast.  On its anticipated track Herold could reach Rodrigues within 24 hours.  Tropical Cyclone Herold is likely to bring gusty winds and locally heavy rain to Port Mathurin and the rest of Rodrigues.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Gretel Speeds By New Caledonia

Tropical Cyclone Gretel sped by New Caledonia on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Gretel was located at latitude 25.9°S and longitude 169.4°E which put it about 750 miles (1210 km) north-northwest of Auckland, New Zealand.  Gretel was moving toward the southeast at 37 m.p.h. (60 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 983 mb.

Tropical Cyclone Gretel moved around the western end of high pressure system over the South Pacific Ocean.  The high steered Gretel rapidly toward the southeast and the tropical cyclone sped over the Coral Sea west of New Caledonia.  Rainbands on the eastern side of Tropical Cyclone Gretel brought wind and rain to portions of New Caledonia on Sunday.

An upper level ridge produced strong northwesterly winds which created strong vertical wind shear.  The wind shear tilted the circulation around Tropical Cyclone Gretel toward the southeast and Gretel began to weaken.  The stronger thunderstorms were occurring in bands south and east of the center of Gretel.  Bands in other parts of the tropical cyclone consisted primarily of showers and lower clouds.  The wind field around Gretel expanded when the tropical cyclone started to weaken.  Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation.

Tropical Cyclone Gretel will continue to move rapidly toward the southeast during the next several days.  On its anticipated track Gretel could pass north of New Zealand in 24 to 36 hours.

Elsewhere, over the South Indian Ocean Tropical Cyclone Herold strengthened east of Madagascar.  At 5:00 p.m EDT on Sunday the center of Tropical Cyclone Herold was located at latitude 15.5°S and longitude 53.2°E which put it about 405 miles (655 km) west-northwest of Port Louis, Mauritius.  Herold was moving toward the east-southeast at 7 m.p.h. (11 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 972 mb.  Tropical Cyclone Herold could reach Rodrigues in about 48 hours.

Tropical Cyclone Herold Drops Heavy Rain Over Northeast Madagascar

Tropical Cyclone Herold dropped heavy rain over parts of northeast Madagascar on Saturday.  A rainband on the western side of Herold was dropping locally heavy rain over northern Madagascar from Mananara to Iharana.  At 5:00 p.m. EST on Saturday the center of Tropical Cyclone Herold was located at latitude 15.0°S and longitude 51.2°E which put it about 545 miles (880 km) northwest of Port Louis, Mauritius.  Herold was moving toward the east at 1 m.p.h. (2 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 981 mb.

Tropical Cyclone Herold strengthened into the equivalent of a hurricane/typhoon on Saturday.  A large ragged circular eye with a diameter of 50 miles (80 km) formed at the center of Herold.  A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  One strong band of showers and thunderstorms wrapped around the eastern and southern sides of Tropical Cyclone Herold.  A second strong band of showers and thunderstorms wrapped around the western and northern sides of Herold.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 85 miles from the center.

Tropical Cyclone Herold will move through an environment favorable for intensification during the next 48 hours.  Herold will move over water where the Sea Surface Temperature is near 29°C.  It will move under an upper level ridge where the winds are weak and there will be little vertical wind shear.  Tropical Cyclone Herold will intensify during the next 48 hours and it could strengthen into the equivalent of a major hurricane.

Tropical Cyclone Herold has been in an area where the steering winds are weak and it has not moved very far during the past 24 hours.  A subtropical high pressure system over the South Indian Ocean will strengthen.  Herold will move around the southwestern part of the high pressure system and the high will steer the tropical cyclone toward the east-southeast.  On its anticipated track Tropical Cyclone Herold will move away from Madagascar on Sunday.  The center of Herold could pass north of Mauritius in three days.  Tropical Cyclone Herold could approach Rodrigues in 84 to 90 hours.

Tropical Cyclone Herold Forms East of Madagascar

Tropical Cyclone Herold formed over the South Indian Ocean east of Madagascar on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Herold was located at latitude 14.8°S and longitude 51.9°E which put it about 510 miles (825 km) northwest of Port Louis, Mauritius.  Herold was moving toward the southwest at 4 m.p.h. (6 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 996 mb.

A distinct low level center of circulation organized quickly in an area of thunderstorms east of Madagascar on Friday and the system was designated as Tropical Cyclone Herold.  The circulation around Herold was still organizing and the distribution of thunderstorms was asymmetrical.  Many of the stronger thunderstorms developed in bands northwest of the center of circulation.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Thunderstorms northwest of the center of Herold were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation.

Tropical Cyclone Herold will move through an environment that will become increasingly favorable for intensification during the next several days.  Herold is currently under a small upper level ridge centered near Madagascar.  The ridge is producing southeasterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear and they are probably the reason for the asymmetrical distribution of thunderstorms.  However, Tropical Cyclone Herold will move into a region where the upper level winds are weaker during the weekend.  Herold will move over water where the Sea Surface Temperature is near 29°C during that time period.  Tropical Cyclone Herold will intensify during the next several days and it could intensify rapidly once the inner core becomes better organized.  Herold is likely to intensify into the equivalent of a hurricane/typhoon during the next 24 hours.  It could strengthen into the equivalent of a major hurricane during the next 72 hours.

Tropical Cyclone Herold is currently in an area where the steering currents are weak.  A subtropical high pressure system over the South Indian Ocean will strengthen during the next several days.  The western end of the subtropical high will start to steer Herold toward the east-southeast during the weekend.  On its anticipated track the center of Tropical Cyclone Herold could be northwest of Mauritius in less than 72 hours.  Herold is likely to be the equivalent of a major hurricane at that time.

Tropical Cyclone Francisco Redevelops Near East Coast of Madagascar

After moving slowly westward across the Southwest Indian Ocean for the past few days, Tropical Cyclone Francisco redeveloped near the east coast of Madagascar on Thursday.  At 7:00 a.m. EST on Thursday the center of Tropical Cyclone Francisco was located at latitude 17.9°S and longitude 50.7°E which put it about 90 miles (145 km) east of Toamasina, Madagascar.  Francisco was moving toward the west at 6 m.p.h. (9 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 1004 mb.

Strong vertical wind shear weakened Tropical Cyclone Francisco east of Rodrigues last Thursday, but the lower portion of the circulation remained intact.  The lower level circulation drifted slowly westward during the last seven days and it moved across Mauritius and La Reunion earlier the week.  More thunderstorms began to develop around the lower level circulation on Wednesday, when it moved closer to the east coast of Madagascar.  Bands of showers and thunderstorms began to reform.  Storms near the center of circulation started generating upper level divergence which pumped mass away from the tropical cyclone.  The removal of mass allowed the surface pressure to decrease and the wind speeds began to increase.

Tropical Cyclone Francisco has exhibited greater organization in recent hours.  However, the distribution of thunderstorms was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Francisco was moving under the northern part of an upper level ridge.  The ridge was producing easterly winds which were blowing toward the top of the circulation.  Those winds were causing some vertical wind shear and the shear could be responsible for the asymmetrical distribution of thunderstorms.

Tropical Cyclone Francisco will move through an environment favorable for intensification during the next 6 to 12 hours.  Francisco will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will still cause vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Francisco will weaken when it moves over Madagascar.

Tropical Cyclone Francisco will move north of a high pressure system over the Southwest Indian Ocean.  The high will steer Francisco toward the west.  On its anticipated track Tropical Cyclone Francisco could make landfall on the east coast of Madagascar in about 12 hours.  Francisco will drop locally heavy rain over parts of central Madagascar.  The heavy rain could cause flash floods in some locations,

Tropical Cyclone Diane Forms North of La Reunion

Tropical Cyclone Diane formed north of La Reunion on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Diane was located at latitude 19.3°S and longitude 56.2°E which put it about 110 miles (175 km) north-northeast of St. Denis, La Reunion.  Diane was moving toward the east-southeast at 18 m.p.h. (30 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 997 mb.

A distinct low level center of circulation developed in an area of low pressure east of Madagascar on Friday and the system was designated as Tropical Cyclone Diane.  The distribution of thunderstorms around Tropical Cyclone Diane was asymmetrical.  Many of the stronger thunderstorms were occurring northwest of the center of circulation.  Bands of showers and thunderstorms were developing east of the center of Diane.  Storms near the center of circulation were beginning to generate upper level divergence which was pumping mass away to the southeast of the tropical cyclone.

Tropical Cyclone Diane will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Diane will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough west of Madagascar and an upper level ridge east of Mauritius will interact to produce northwesterly winds which will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  Tropical Cyclone Diane could intensify slowly during the next 24 to 36 hours.

The upper level trough and upper level ridge will steer Tropical Cyclone Diane toward the east-southeast during the next several days.  On its anticipated track Tropical Cyclone Diane could bring wind and rain to Mauritius within 12 hours.  Locally heavy rain could cause flash floods in some locations.

Tropical Cyclone Calvinia Develops East of Mauritius

Tropical Cyclone Calvinia developed east of Mauritius on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Calvinia was located at latitude 20.7°S and longitude 58.7°E which put it about 105 miles (165 km) east-southeast of Port Louis, Mauritius.  Calvinia was moving toward the southwest at 6 m.p.h. (10 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.

A distinct low level center of circulation developed in an area of thunderstorms east of Mauritius on Sunday and the system was designated at Tropical Cyclone Calvinia.  The circulation around Tropical Cyclone Calvinia was asymmetrical.  Many of the stronger thunderstorms were occurring in bands on the eastern side of the circulation.  Bands north and west of the center of Calvinia consisted primarily of showers and lower clouds.  The distributions of strong winds around the tropical cyclone was also asymmetrical.  Winds to tropical storm force extended out 200 miles (320 km) on the eastern side of the circulation.  Winds to tropical storm force only extended out 60 miles (95 km) on the western side.

Tropical Cyclone Calvinia will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Calvinia will move over water where the Sea Surface Temperature is near 27°C.  It will move east of an upper level trough.  The trough will produce northwesterly winds which will blow toward the top of the circulation.  The winds will cause moderate vertical wind shear and they are probably the reason for the asymmetrical structure of Tropical Cyclone Calvinia.  Calvinia could strengthen during the next several days, but the wind shear is likely to prevent significant intensification.

The upper level trough will steer Tropical Cyclone Calvinia toward the southeast.  On its anticipated track Calvinia will move away from Mauritius and La Reunion.  Since Tropical Cyclone Calvinia will be east of Mauritius, the strongest part of the circulation will remain east of Mauritius and La Reunion.

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 Cyclone Haleh Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Haleh strengthened into the equivalent of a major hurricane on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Haleh was centered at latitude 18.9°S and longitude 72.3°E which put it about 800 miles (1290 km) south of Diego Garcia.  Haleh was moving toward the south-southwest at 10 m.p.h. (16 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 948 mb.

Tropical Cyclone Haley rapidly intensified into the equivalent of a major hurricane during the past 24 hours.  A circular eye was clearly evident on satellite imagery.  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 the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Haleh.  The strongest bands were in the southern half of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.

Winds to hurricane/typhoon force extended out about 50 miles (80 km) from the center of Tropical Cyclone Haleh.  Winds to tropical storm force extended out about 210 miles (330 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Haleh was 22.1.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 38.1.

Tropical Cyclone Haleh will move through an environment favorable for intensification during the next 24 hours.  Haleh will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Tropical Cyclone Haleh could intensify during the next day or so.  Eventually, Haleh will move over cooler water and it will start to weaken when that occurs.

Tropical Cyclone Haleh will move around the western end of a subtropical ridge over the South Indian Ocean.  The ridge will steer Haleh toward the south-southwest.  On its anticipated track Tropical Cyclone Haleh is forecast to remain well to the southeast of Mauritius and La Reunion.