Tropical Cyclone Dineo intensified on Tuesday as it moved closer to Mozambique. At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Dineo was located at latitude 22.8°S and longitude 37.5°E which put it about 160 miles (260 km) east-northeast of Inhambane, Mozambique. Dineo was moving toward the west-southwest at 7 m.p.h. (11 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 981 mb.
Tropical Cyclone Dineo intensified on Tuesday and it was on the verge of reaching the intensity of a hurricane/typhoon. A primary rainband wrapped most of the way around a circular eye. There was a break on the western side of the developing eyewall. The strongest winds were occurring in thunderstorms in the eyewall. Several other bands of showers and thunderstorms were rotating around the core of Tropical Cyclone Dineo. Thunderstorms around the core of Dineo were generating upper level divergence which was transporting mass away from the center of the tropical cyclone.
Tropical Cyclone Dineo will move through a favorable environment until it reaches Mozambique. Dineo will move over water where the Sea Surface Temperature is near 30°C. The upper level winds are weak and there is little vertical wind shear. The favorable environment will allow Tropical Cyclone Dineo to continue to intensify during the next 12 to 18 hours. It will become the equivalent of a hurricane/typhoon on Wednesday.
A subtropical ridge is steering Tropical Cyclone Dineo toward the west-southwest and that general motion is expected to continue for another 12 to 24 hours. On its anticipated track Tropical Cyclone Dineo is expected to make landfall on the coast of Mozambique north of Inhambane in less than 24 hours. Tropical Cyclone Dineo will be the equivalent of a hurricane/typhoon when it makes landfall. Dineo will bring strong winds and locally heavy rain when it moves into Mozambique. Heavy rain could create the potential for flash floods. Tropical Cyclone Dineo will also produce a storm surge along the coast. The highest storm surge will occur south of where the center makes landfall as the clockwise rotation pushes water toward the coast.
Tropical Cyclone Dineo started to move slowly toward Mozambique on Monday. At 10:00 p.m. EST on Monday the center of Tropical Cyclone Dineo was located at latitude 22.0°S and longitude 38.9°E which put it about 265 miles (430 km) east-northeast of Inhambane, Mozambique. Dineo was moving toward the west-southwest at 6 m.p.h. (10 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 994 mb.
The circulation of Tropical Cyclone Dineo became more organized on Monday. A primary rainband wrapped tightly around the eastern side of the center of circulation. Recent microwave satellite imagery hinted at the formation of an eye at the center of circulation and a broken eyewall around the developing eye. The strongest winds were occurring in thunderstorms in the primary rainband. Additional bands of thunderstorms developed in the eastern half of the circulation. A few thunderstorms formed west of the center, but most of the bands in that part of the circulation consist of low clouds and showers. There may be some drier air in the western part of the circulation and the drier air may be inhibiting the development of thunderstorms in that region. The thunderstorms near the center of circulation are generating upper level divergence.
Tropical Cyclone Dineo will be moving through a favorable environment during the next 24 hours. It will be moving over water where the Sea Surface Temperature is near 30°C. An upper level ridge centered over southern Africa will produce southwesterly winds that will blow toward the top of the circulation. Those winds will produce some wind shear and they will limit upper level divergence on the western side of the circulation. While the wind shear may slow the rate of intensification during the next 24 hours, Tropical Cyclone Dineo should strengthen on Tuesday. Dineo could intensify into the equivalent of a hurricane/typhoon before it reaches the coast of Mozambique.
Tropical Cyclone Dineo is near the western end of a subtropical ridge which is steering it slowly toward the west-northwest. That ridge is expected to continue to steer Tropical Cyclone Dineo toward the west-northwest during the next 12 to 24 hours. Eventually, the ridge is expected to get stronger and extend westward. When that happens, the ridge could steer Dineo more toward the west. On its anticipated track Tropical Cyclone Dineo could approach the coast of Mozambique north of Inhambane in 24 to 30 hours.
Tropical Cyclone Dineo could be the equivalent of a hurricane/typhoon when it reaches Mozambique. It will bring gusty winds and heavy rain to parts of Mozambique. Dineo could also generate a storm surge at the coast when it makes landfall.
A surface circulation organized quickly inside a low pressure system over the Mozambique Channel on Sunday and the system was designated as Tropical Cyclone 05S. At 7:00 p.m. EST on Sunday the center or Tropical Cyclone 05S was located at latitude 21.6°N and longitude 39.9°E which put it about 540 miles (870 km) northeast of Maputo, Mozambique. Tropical Cyclone 05S was moving toward the south-southwest at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1000 mb.
Tropical Cyclone 05S has a tight center of circulation, but the distribution of thunderstorms is asymmetrical. Multiple bands of thunderstorms developed in the eastern half of the circulation. The strongest winds are occurring in the bands of thunderstorms. However, there are mainly showers and a few isolated thunderstorms in the bands in the western half of the circulation. The thunderstorms in the bands east of the center of circulation are beginning to generate upper level divergence.
Tropical Cyclone 05S will be moving through a favorable environment during the next several days. It will be moving over water where the Sea Surface Temperature is near 30°C. Tropical Cyclone 05S is underneath an upper level ridge. The upper level winds are weak and there is not much vertical wind shear. There may be some drier air in the western half of the circulation and that is the only inhibiting factor in the environment around Tropical Cyclone 05S. Given the mostly favorable environment Tropical Cyclone 05S is likely to intensify during the next day or two. If an inner core becomes fully developed, then a period of rapid intensification may be possible.
Tropical Cyclone 05S is currently in an area of weak steering currents because of its position underneath the upper level ridge. Some global models are indicating that a track toward the southwest could be possible if the tropical cyclone moves closer to the western portion of the ridge. On its anticipated track Tropical Cyclone 05S could move in the general direction of Mozambique.
Thunderstorms near the center of Tropical Cyclone Fantala dissipated and it weakened as moved northeast of Madagascar. At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Fantala was located at latitude 11.5°S and longitude 54.5°E which put it about 350 miles (565 km) east of Antsirañana, Madagascar. Fantala was moving west-northwest at 10 m.p.h. (16 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 988 mb.
Tropical Cyclone Fantala reversed course again on Saturday and it is moving over the same part of the South Indian Ocean that it already crossed twice during the past few days. The winds produced by Fantala mixed cooler water up to to the surface of the ocean during its previous passages over the same region. The cooler water means that there is less energy available to power the circulation of Tropical Cyclone. Although the winds continue to rotate around the center of circulation, there are no thunderstorms near the core of Fantala. There are still several thunderstorms in rainbands farther to the east of the center of circulation.
If new thunderstorms do not develop around the core of the circulation, the winds will gradually spin down and the tropical cyclone will dissipate within a few days. Upper level winds blowing from the west-northwest are also generating some vertical wind shear, which will make it more difficult for new thunderstorms to form.
A subtropical ridge southwest of Fantala is steering the tropical cyclone toward the west-northwest and that general motion is expected to continue for the next several days. On its anticipated track Tropical Cyclone Fantala is forecast to pass north of Madagascar and move over the Seychelles. It could be even weaker by the time it gets to the Seychelles.
Tropical Cyclone Fantala moved into an area of weaker steering currents on Thursday and it stalled about 500 miles (800 km) east of northern Madagascar. At 5:00 p.m. EDT on Thursday the center of Tropical Cyclone Fantala was located at latitude 13.0°S and longitude 56.7°E which put it about 515 miles (830 km) east of Antsirañana, Madagascar. Fantala was moving toward the southeast at 5 m.p.h. (8 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.
Although Fantala weakened slightly on Thursday, the structure of the inner core of the circulation remained fairly intact. A thin ring of thunderstorms was wrapped around an that was obscured on conventional satellite imagery. Other bands of thunderstorms spiraled around the eyewall. The thunderstorms in the core of Fantala were generating upper level divergence to the north and east of the center of circulation. It appears that drier air may be getting pulled into the eastern portion of the circulation outside the core of Fantala. There only only isolated thunderstorms in the rainbands in that part of the circulation.
The environment is marginally favorable for intensification. The upper level winds are light enough so there is only a moderate amount of vertical wind shear. Fantala is over water where the Sea Surface Temperature is near 29°C. However, because Fantala is moving so slowly, it could mix cooler water to the surface which would reduce the energy available to the tropical cyclone. In addition the drier air will also limit the supply of energy being transported into the core of the circulation.
Tropical Cyclone Fantala has moved into an area where the steering currents are weak. It may not move much during the next 24 hours. A subtropical ridge is forecast to develop southwest of Fantala in a day or two. When the subtropical ridge develops, it is expected to steer Fantala back toward the west again. On its anticipated track Tropical Cyclone Fantala could be approaching the northern part of Madagascar in 60 to 72 hours.
A low level circulation developed enough organization on the eastern side of a cluster of thunderstorms over the Mozambique Channel to be classified as a tropical cyclone on Thursday. At 11:00 p.m. EST on Thursday the center of Tropical Cyclone 15S was located at latitude 16.6°S and longitude 42.3° which put it about 110 miles east-southeast of Mogincual, Mozambique and about 200 miles northwest of Maintirano, Madagascar. It was moving toward the south-southeast at 5 m.p.h. The maximum sustained wind speed was 40 m.p.h. and there were wind gusts to 50 m.p.h. The minimum surface pressure was 996 mb.
Southeasterly winds in the upper levels are creating vertical wind shear and most of the stronger thunderstorms are on the western side of the center of circulation. However, the tropical cyclone is over warm Sea Surface Temperatures and some intensification is possible. If the upper level winds decrease, the more rapid intensification could occur. A gradual intensification seems more likely over the short term.
A subtropical ridge of high pressure to the east of the tropical cyclone is steering it slowly to the south. It is likely to move into a region of weak steering winds between that ridge of high pressure and another ridge farther to the west. As a result, the tropical cyclone could move slowly and erratically and even become stationary at times during the next day or two. Eventually, a third ridge of high pressure is expected to develop to the north of the system and push it westward toward Madagascar.
The tropical cyclone could be a strong tropical storm or near hurricane intensity when it reaches Madagascar. Some wind damage is possible, but the biggest threat appears to be from locally heavy rainfall and flooding.