Tag Archives: SH22

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 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.