Tag Archives: 21S

Tropical Cyclone Halima Forms South of Diego Garcia

Tropical Cyclone Halima formed south of Diego Garcia on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Cyclone Halima was located at latitude 13.4°S and longitude 75.7°E which put it about 485 miles (780 km) south-southeast of Diego Garcia. Halima was moving toward the west-southwest at 9 m.p.h (15 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.

The circulation around a low pressure system over the South Indian Ocean south of Diego Garcia strengthened on Wednesday and the system was designated at Tropical Cyclone Halima. More thunderstorms formed west of the center of Halima’s circulation. The strongest thunderstorms were occurring in bands in the western half of Tropical Cyclone Halima. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 90 miles (145 km) from the center of Halima.

Tropical Cyclone Halima will move through an environment favorable for intensification during the next 36 hours. Halima will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the northern part of an upper level ridge over the South Indian Ocean. The ridge will produce easterly winds that will blow toward the top of Halima’s circulation. Those winds will cause some vertical wind shear, but the shear will not be enough to prevent intensification. Tropical Cyclone Halima will intensify during the next 36 hours and it could strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Halima will move around the western end of a high pressure system over the South Indian Ocean during the next 36 hours. The high pressure system will steer Halima toward the south. On its anticipated track Tropical Cyclone Halima will move farther away from Diego Garcia.

Elsewhere over the South Indian Ocean, Tropical Cyclone Charlotte weakened gradually northwest of Australia. At 11:00 a.m. EDT on Wednesday the center of Tropical Cyclone Charlotte was located at latitude 20.4°S and longitude 107.6°E which put it about 430 miles (695 km) west-northwest of Learmonth, Australia. Charlotte was moving toward the south-southwest at 13 m.p.h (20 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 Charlotte Spins Northwest of Australia

Tropical Cyclone Charotte was spinning over the South Indian Ocean northwest of Australia on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Charlotte was located at latitude 18.5°S and longitude 108.7°E which put it about 435 miles (700 km) northwest of Learmonth, Australia. Charlotte was moving toward the south-southwest at 6 m.p.h (10 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 973 mb.

Tropical Cyclone Charlotte continued to spin over over the South Indian Ocean northwest of Australia on Tuesday night. The environment around Charlotte became less favorable for a tropical cyclone on Tuesday evening and the tropical cyclone was beginning to be affected the different environment. The ring of thunderstorms around the eye weakened and the overall distribution of thunderstorms became asymmetrical. The strongest thunderstorms were occurring in bands in the southern half of the circulation around Tropical Cyclone Charlotte. Bands in the northern half of the tropical cyclone consisted primarily of showers and lower clouds. Storms near the center of circulation were still generating upper level divergence that pumped mass away to the southeast of the tropical cyclone. Winds to tropical storm force extended out 125 miles (200 km) from the center of Tropical Cyclone Charlotte.

Tropical Cyclone Charlotte will continue to be in an environment unfavorable for a tropical cyclone during the next several days. Charlotte will move over water where the Sea Surface Temperatures are near 28˚C. An upper level trough over the South Indian Ocean will approach Charlotte from the west. The trough will produce northwesterly winds that will blow toward the top of Charlotte’s circulation. Those winds will cause moderate vertical wind shear. The flow of air around Tropical Cyclone Charlotte could also pull drier air into the western and northern parts of the circulation. The wind shear and the drier air will cause Tropical Cyclone Charlotte to weaken during the next several days.

Tropical Cyclone Charlotte will move around the western part of a high pressure system over Australia during the next 36 hours. The high pressure system will steer Charlotte toward the south. On its anticipated track Tropical Cyclone Charlotte will move parallel to the coast of Western Australia. Charlotte will remain west of the coast during the next 36 hours.

Tropical Cyclone Charlotte Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Charlotte strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean northwest of Australia on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Charlotte was located at latitude 16.4°S and longitude 109.6°E which put it about 500 miles (805 km) northwest of Learmonth, Australia. Charlotte was moving toward the southwest at 9 m.p.h (15 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 973 mb.

Tropical Cyclone Charlotte continued to intensify on Monday. A small circular eye formed at the center of Charlotte’s circulation. The 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 small core of Tropical Cyclone Charlotte. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone. Winds to hurricane/typhoon force extended out 15 miles (25 km) from the center of circulation. Winds to tropical storm force extended out 140 miles (225 km) from the center.

Tropical Cyclone Charlotte will move through an environment favorable for intensification during the next 24 hours. Charlotte will move over water where the Sea Surface Temperatures are 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 Charlotte is likely to continue to intensify during the next 24 hours. An upper level trough over the South Indian Ocean will approach Charlotte from the west in a day or so. The trough will produce northwesterly winds and those winds will cause the vertical wind shear to increase. Tropical Cyclone Charlotte will start to weaken when the wind shear increases.

Tropical Cyclone Charlotte will move around the northwestern part of a high pressure system over Australia during the next 24 hours. The high pressure system will steer Charlotte toward the southwest. On its anticipated track Tropical Cyclone Charlotte will move parallel to the coast of Western Australia during the next 24 hours. Charlotte will remain far away from the coast during the next several days.

Tropical Cyclone Charlotte Develops Quickly Northwest of Australia

Tropical Cyclone Charlotte developed quickly over the South Indian Ocean northwest of Australia on Sunday. At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Charlotte was located at latitude 14.9°S and longitude 111.5°E which put it about 550 miles (890 km) north-northwest of Learmonth,, Australia. Charlotte was moving toward the southwest at 15 m.p.h (24 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 985 mb.

A low pressure system over the South Indian Ocean northwest of Australia strengthened quickly on Sunday and the Australia Bureau of Meteorology designated the system as Tropical Cyclone Charlotte. The circulation around Tropical Cyclone Charlotte organized rapidly. The inner end of a rainband wrapped around the southern and western sides of the center of circulation and an eye appeared to be forming. Bands of showers and thunderstorms were revolving around the core of Charlotte’s circulation. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation.

Tropical Cyclone Charlotte will move through an environment favorable for intensification during the next 24 hours. Charlotte will move over water where the Sea Surface Temperatures are 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 Charlotte is likely to continue to intensify rapidly during the next 24 hours. Charlotte is likely to strengthen to the equivalent of a hurricane/typhoon during the next 12 hours.

Tropical Cyclone Charlotte will move around the northwestern part of a high pressure system over Australia during the next 24 hours. The high pressure system will steer Charlotte toward the west-southwest. On its anticipated track Tropical Cyclone Charlotte will move parallel to the coast of Western Australia during the next 24 hours. Charlotte will remain well away from the coast on Monday.

Tropical Cyclone Guambe Moves away from Mozambique

Tropical Cyclone Guambe moved away from Mozambique on Saturday. At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Guambe was located at latitude 29.1°S and longitude 38.1°E which put it about 400 miles (645 km) southeast of Maputo, Mozambique. Guambe was moving toward the southeast at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 973 mb.

Tropical Cyclone Guambe appeared to develop concentric eyewalls on Saturday which caused the circulation to weaken. The maximum sustained wind speed decreased when the original, small inner eyewall dissipated. There were fewer thunderstorms around the center of Guambe on Saturday night. The strongest thunderstorms were occurring in bands in the western half of the circulation. Bands in the eastern half of Tropical Cyclone Guambe contained more showers and lower clouds. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of circulation. Winds to tropical storm force extended out 110 miles (175 km) from the center.

Tropical Cyclone Guambe will move into an environment that will be capable of sustaining a tropical cyclone during the next 24 hours. Guambe will move over water where the Sea Surface Temperatures will be near 26°C, but it will gradually move over colder water. An upper level trough south of Africa will approach Tropical Cyclone Guambe from the west. The trough will produce northwesterly winds which will blow toward the top of Guambe. Those winds will cause more vertical wind shear when they reach Tropical Cyclone Guambe. The combination of more vertical wind shear and colder water will cause the structure of Guambe to being a transition to an extratropical cyclone.

The upper level trough will steer Tropical Cyclone Guambe toward the southeast during the next two days. On its anticipated track Guambe will move farther away from Mozambique. Tropical Cyclone Guambe is forecast to pass well to the south of Madagascar.

Tropical Cyclone Guambe Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Guambe strengthened to the equivalent of a hurricane/typhoon over the Mozambique Channel on Friday. At 4:00 p.m. EST on Friday the center of Tropical Cyclone Guambe was located at latitude 25.4°S and longitude 36.4°E which put it about 260 miles (415 km) east of Maputo, Mozambique. Guambe was moving toward the south-southwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 958 mb.

Tropical Cyclone Guambe continued to intensify over the warm water in the Mozambique Channel on Friday. A small circular eye with a diameter of 8 miles (13 km) was present at the center of Guambe. 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 Tropical Cyclone Guambe generated upper level divergence which pumped mass away from the tropical cyclone. Bands of showers and thunderstorms were revolving around the core of Guambe.

The circulation around Tropical Cyclone Guambe was relatively small. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Guambe. Winds to tropical storm force extended out 175 miles (280 km) on the eastern side of the circulation. Winds to tropical storm force extended out 100 miles (160 km) on the western side of the circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Guambe was 16.5. The Hurricane Size Index (HSI) was 11.5 and the Hurricane Wind Intensity Size Index (HWISI) was 28.0.

Tropical Cyclone Guambe will move into an environment that will be favorable for intensification during the next 24 hours. Guambe will move over water where the Sea Surface Temperature is near 29°C. It will move under the center of an upper level ridge. The winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Cyclone Guambe could strengthen into the equivalent of a major hurricane during the next 24 hours. If the inner end of a rainband wraps around the existing small eye and eyewall, then an eyewall replacement cycle could cause Guambe to weaken.

Tropical Cyclone Guambe will move around the western side of a subtropical high pressure system over the South Indian Ocean. The high will steer Guambe slowly toward the south during the next 24 hours. On its anticipated track Tropical Cyclone Guambe will move parallel to the coast of Mozambique. The center of Guambe is forecast to remain over the Mozambique Channel, but rainbands on the western side of the tropical cyclone could bring gusty winds and heavy rain to parts of the coast of southern Mozambique.

Tropical Cyclone Guambe Intensifies East of Mozambique

Tropical Cyclone Guambe intensified east of Mozambique on Thursday. At 7:00 p.m. EST on Thursday the center of Tropical Cyclone Guambe was located at latitude 24.2°S and longitude 37.3°E which put it about 130 miles (210 km) east of Inhambane, Mozambique. Guambe was moving toward the south at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 70 m.p.h. (120 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 976 mb.

Tropical Cyclone Guambe intensified to nearly the equivalent of a hurricane/typhoon over the Mozambique Channel on Thursday night. A small circular eye at the center of Guambe was evident on microwave satellite images. The 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 Tropical Cyclone Guambe. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Tropical Cyclone Guambe will move into an environment that will be favorable for intensification during the next 24 hours. Guambe will move over water where the Sea Surface Temperature is near 29°C. It will move under the center of an upper level ridge. The winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Cyclone Guambe will strengthen into the equivalent of a hurricane/typhoon during the next 6 hours. Guambe could intensify rapidly for a period of time and it could strengthen into the equivalent of a major hurricane during the next 36 hours.

Tropical Cyclone Guambe will move around the western side of a subtropical high pressure system over the South Indian Ocean. The high will steer Guambe slowly toward the south during the next 36 hours. On its anticipated track Tropical Cyclone Guambe will move parallel to the coast of Mozambique. Rainbands on the western side of Guambe could bring gusty winds and heavy rain to the coast of southern Mozambique.

Tropical Cyclone Guambe Forms over Mozambique Channel

Tropical Cyclone Guambe formed over the Mozambique Channel on Wednesday. At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Guambe was located at latitude 21.4°S and longitude 37.5°E which put it about 150 miles (240 km) east-northeast of Vilanculos, Mozambique. Guambe was moving toward the south at 3 m.p.h. (5 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.

A low pressure system moved eastward from southern Africa over the Mozambique Channel and Meteo France la Reunion designated the system as Tropical Cyclone Guambe. The circulation around Tropical Cyclone Guambe exhibited more organization after it moved over the warm water in the Mozambique Channel. Bands of showers and thunderstorms revolved around the center of Guambe. Storms near the center of circulation began to generate upper level divergence which pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 150 miles (240 km) from the center.

Tropical Cyclone Guambe will move into an environment that will be very favorable for inensification during the next 48 hours. Guambe will move over water where the Sea Surface Temperature is near 29°C. It will move under the center of an upper level ridge. The winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Cyclone Guambe will strengthen during the next 48 hours and it could intensify rapidly after an inner core develops. Guambe is forecast to strengthen into the equivalent of a hurricane/typhoon during the next 48 hours.

Tropical Cyclone Guambe will move around the western side of a subtropical high pressure system over the South Indian Ocean. The high will steer Guambe slowly toward the south during the next several days. On its anticipated track Tropical Cyclone Guambe will move parallel, but close to the coast of Mozambique. Guambe will produce gusty winds and it will drop heavy rain near the coast of Mozambique.

Major Tropical Cyclone Joaninha Brings Wind and Rain to Rodrigues

Major Tropical Cyclone Joaninha brought wind and rain to Rodrigues on Monday night.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Joaninha was located at latitude 19.3°S and longitude 63.9°E which put it about 45 miles (75 km) from Rodrigues, Mauritius.  Joaninha was moving toward the southeast at 10 m.p.h. (16 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 946 mb.

Tropical Cyclone Joaninha was the equivalent of a major hurricane.  Winds to hurricane/typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 180 miles (290 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Joaninha was 23.6.  The Hurricane Size Index (HSI) was 18.7 and the Hurricane Wind Intensity Size Index (HWISI) was 42.3.  Joaninha was capable of causing major damage.

The southwestern portion of the eyewall of Tropical Cyclone Joaninha was very near Rodrigues.  Winds to hurricane typhoon force were occurring in that part of the eyewall.  Winds to tropical storm force are likely to affect all of Rodrigues.  The circulation around Joaninha was somewhat asymmetrical.  Most of the stronger rainbands were occurring in the eastern half of the circulation and the heaviest rain is likely to fall east of Rodrigues.  However, heavy rain in the eyewall could cause flooding in some locations.

Tropical Cyclone Joaninha will move through an environment favorable for intensification during the next 24 hours.  Joaninha will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where there will be little vertical wind shear.  Tropical Cyclone Joaninha could strengthen slightly while it passes by Rodrigues.

An upper level trough near Madagascar will produce northwesterly winds which will steer Tropical Cyclone Joaninha toward the southeast.  On its anticipated track Joaninha will move away from Rodrigues on Tuesday.  Conditions in Rodrigues should improve gradually as Tropical Cyclone Joaninha moves away.

Elsewhere over the South Indian Ocean, weakening Tropical Cyclone Veronica was skirting the coast of Western Australia.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Veronica was located at latitude 21.1°S and longitude 115.4°E which put it about 140 miles (230 km) northeast of Learmonth, Australia.  Veronica was moving toward the 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 992 mb.  Tropical Cyclone Veronica dropped heavy rain over parts of Western Australia and flooding was occurring in some locations.

Tropical Cyclone Veronica Stalls, Weakens Near Western Australia Coast

Tropical Cyclone Veronica stalled and weakened near the coast of Western Australia west of Port Hedand.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Veronica was located at latitude 20.5°S and longitude 117.5°E which put it about 70 miles (110 km) west of Port Hedland.  Veronica was moving toward the southwest at 2 m.p.h. (3 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 974 mb.  A Tropical Cyclone Warning remained in effect from Port Hedland to Mardie including Karratha and Barrow Island.

The southern eyewall of Tropical Cyclone Veronica moved over the coast of Western Australia west of Port Hedland on Saturday night.  Veronica was the equivalent of a major hurricane and there would have been a period of strong winds near the coast.  It likely caused some wind damage and generated a storm surge at the coast.  An upper level trough west of Australia produced strong northwesterly winds that reached the top of Tropical Cyclone Veronica as it neared the coast.  Those winds produced very strong vertical wind shear and they blew the upper half of the circulation southeast of the lower half of the tropical cyclone.  The decoupling of the upper and lower parts of the circulation caused Tropical Cyclone Veronica to weaken very quickly during the past 12 hours.  Veronica weakened from the equivalent of a major hurricane to a tropical storm.

The strong wind shear also generated an asymmetrical distribution of rainfall.  Most of the rain was falling in the southeastern half of the circulation which was over Western Australia.  Bands in the northwestern half of the circulation consisted primarily of showers and lower clouds.  Locally heavy rain could produce flooding in a few locations, but the rapid weakening of Tropical Cyclone Veronica will reduce the risk of flooding.

Tropical Cyclone Veronica will continue to weaken quickly because of the strong vertical wind shear.  The decoupling of the upper and lower halves of the circulation has resulted in little motion during the past few hours.  However, the lower half of Veronica will be steered more by the winds in the lower troposphere.  Those winds will steer Tropical Cyclone Veronica toward the west-southwest during the next day or two.  On its anticipated track the lower half of Veronica will move near the coast of Western Australia.  On its anticipated track Tropical Cyclone Veronica will pass near Wickham, Karratha, Dampier, Onslow and Exmouth.  Veronica will bring some gusty winds, but it should pose a limited risk.

Elsewhere over the South Indian Ocean, Tropical Cyclone Joaninha was strengthening northwest of Rodrigues.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Joaninha was located at latitude 17.4°S and longitude 62.0°E which put it about 180 miles (290 km) northwest of Rodrigues, Mauritius.  Joaninha was moving toward the southeast at 2 m.p.h. (3 km/h).  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).  The minimum surface pressure was 956 mb.