Tropical Cyclone Jobo moved toward Tanzania on Thursday. At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Jobo was located at latitude 9.1°S and longitude 43.6°E which put it about 335 miles (535 km) east-southeast of Dar es Salaam, Tanzania. Jobo was moving toward the west-northwest at 9 m.p.h. (15 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.
The intensity and organization of Tropical Cyclone Jobo fluctuated during the past 48 hours as the strength of the upper level winds changed. At times Jobo intensified to the equivalent of a strong tropical storm when the upper levels winds diminished. Whenever the upper level winds were stronger, vertical wind shear caused the circulation to weaken. Tropical Cyclone Jobo was intensifying again on Thursday night. The inner end of a rainband wrapped around the southern and western sides of the center of circulation. Thunderstorms near the center generated more upper level divergence that pumped mass away from the tropical cyclone. The circulation of Tropical Cyclone Jobo was small, which was why vertical wind shear had such a big effect on the tropical cyclone. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.
Tropical Cyclone Jobo will move through an environment favorable for intensification during the next 36 hours. Jobo will move over water where the Sea Surface Temperatures will be near 29°C. Jobo will move under the middle of an upper level ridge over southern Africa and the Southwest Indian Ocean. The winds are weaker near the middle of the ridge and there will be less vertical wind shear. Tropical Cyclone Jobo could strengthen during the next 36 hours, but any increase in the wind shear could cause the small circulation to weaken again.
Tropical Cyclone Jobo will move around the northern side of a subtropical high pressure system over southern Africa. The high will steer Jobo toward the west-northwest during the next several days. On its anticipated track Tropical Cyclone Jobo could approach the coast of Tanzania in 36 hours.
Tropical Cyclone Jobo formed just to the north of Madagascar on Tuesday afternoon. At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Jobo was located at latitude 10.3°S and longitude 49.8°E which put it about 100 miles (160 km) north of Ansiranana, Madagascar. Jobo was moving toward the west at 13 m.p.h. (20 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 995 mb.
The circulation around a low pressure system north of Madagascar strengthened on Tuesday afternoon and Meteo France la Reunion designated the system as Tropical Cyclone Jobo. The distribution of thunderstorms around Tropical Cyclone Jobo was asymmetrical. Many of the stronger thunderstorms were occurring in bands on the western side of Jobo. Bands on the eastern side of the circulation consisted primarily of showers and lower clouds. The inner end of a rainband was wrapping around the western side of the center of circulation. Storms near the center started to generate upper level divergence that pumped mass away to the north and west of the tropical cyclone. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation.
Tropical Cyclone Jobo will move through an environment favorable for intensification during the next 36 hours. Jobo will move over water where the Sea Surface Temperatures will be near 29°C. It will move near the northern part of a small upper level ridge. The ridge will produce southeasterly winds which will blow toward the top of the tropical cyclone. Those winds will cause some vertical wind shear. The shear will inhibit intensification, but the wind shear will not be large enough to prevent Tropical Cyclone Jobo from strengthening. Some numerical models are forecasting that Jobo could intensify into the equivalent of a hurricane/typhoon later this week.
Tropical Cyclone Jobo will move north of a surface high pressure system over the Southwest Indian Ocean. The high will steer Jobo slowly toward the west during the next several days. On its anticipated track Tropical Cyclone Jobo will remain north of Madagascar. The steering currents could weaken later this week and Jobo could stall northwest of Madagascar.