Tag Archives: Madgascar

Tropical Cyclone Eloise nears Northern Madagascar

Tropical Cyclone Eloise neared northern Madagascar on Monday. At 4:00 p.m. EST on Monday the center of Tropical Cyclone Eloise was located at latitude 14.3°S and longitude 52.0°E which put it about 125 miles (200 km) east of Antalaha, Madagascar. Eloise was moving toward the west at 23 m.p.h. (37 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 Eloise strengthened as it quickly neared northern Madagascar on Sunday. The inner end of a rainband wrapped around the center of Eloise. More thunderstorms formed in bands revolving around the center of circulation. Storms near the center generated upper level divergence which pumped mass away from the tropical cyclone. The circulation became more symmetrical. Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation.

Tropical Cyclone Eloise will move through an environment somewhat favorable for intensification during the next few hours before it reaches northern Madagascar. Eloise will move over water where the Sea Surface Temperature is near 28°C. It will move under the northern portion of an upper level ridge over the South Indian Ocean. The ridge will produce easterly winds which will blow toward the top of the tropical cyclone. Those winds will cause some vertical wind shear which will inhibit intensification. Tropical Cyclone Eloise could intensify until it moves over Madagascar.

Tropical Cyclone Eloise will move north of a high pressure system over the South Indian Ocean. The high will steer Eloise toward the west-southwest during the next 48 hours. On its anticipated track Tropical Cyclone Eloise could make landfall on the northeastern coast of Madagascar near Antahala in a few hours. Eloise will produce gusty winds and heavy rain over northern Madagascar. Heavy rain could cause flash floods in some locations.

Elsewhere over the South Indian Ocean, Tropical Cyclone Joshua moved far to the southeast of Diego Garcia. At 11:00 a.m. EST on Monday the center of Tropical Cyclone Joshua was located at latitude 19.8°S and longitude 87.5°E which put it about 1335 miles (2150 km) southeast of Diego Garcia. Joshua was moving toward the southwest at 9 m.p.h. (15 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.

Tropical Cyclone Enawo Forms North of La Reunion

Tropical Cyclone Enawo formed north of La Reunion on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Enawo was located at latitude 13.2°S and longitude 56.2°E which put it about 520 miles (835 km) north of St. Denis, La Reunion.  Enawo was moving toward the southwest at 4 m.p.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.

An area of low pressure organized slowly over the southwest Indian Ocean during the past few days.  Bands of thunderstorms formed west of the center of circulation and some of the bands began to wrap closer to the center on Friday.  The low pressure system exhibited the characteristic structure of a developing tropical cyclone and it was designated Tropical Cyclone Enawo.  Although there are more thunderstorms near the center of circulation, the distribution of the storms is still asymmetrical.  There are many more thunderstorms in the western half of the circulation.  The asymmetry probably indicates that some vertical wind shear is slowing the organization of the circulation.

Tropical Cyclone Enawo will be moving through an environment favorable for intensification during the next several days.  It will be moving over water where the Sea Surface Temperature is near 30°C.  Enawo is northwest of an upper level ridge which is generating easterly winds that are blowing toward the top of the circulation.  The upper level ridge could be the source of the vertical wind shear that is slowing the intensification of the tropical cyclone.  The upper level wind shear could decrease during the weekend and Tropical Cyclone Enawo is likely to intensify into the equivalent of a hurricane/typhoon.  Once an inner core become well established at the center of circulation, a period of rapid intensification may be possible.

A subtropical ridge located southeast of Enawo is steering the tropical cyclone toward the southwest.  Guidance from the numerical models is divergent about the future strength of the ridge.  Some of the models, like the Global Forecasting System,  are predicting a weaker ridge and turn Tropical Cyclone Enawo more toward the south.  Other models, such as the European Center for Medium Range Forecasting System model, strengthen the subtropical ridge and steer Tropical Cyclone Enawo west toward northeast Madagascar.  Given the uncertainty in both the track and intensity forecasts, interests in the southwest Indian Ocean should monitor Tropical Cyclone Enawo closely.