Tag Archives: South Atlantic

Iba Develops Into Rare South Atlantic Tropical Storm

Tropical Storm Iba developed into a rare South Atlantic Tropical Storm on Sunday.  At 8:00 p.m. EDT on Sunday the center of Tropical Storm Iba was located at latitude 19.2°S and longitude 36.0°S which put it about 260 miles (420 km) east of Linhares, Brazil.  Iba was moving toward the south at 3 m.p.h. (5 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 1000 mb.

More thunderstorms developed near the center of a low pressure system off the east coast of Brazil and the Instituto Nacional de Meteorologia designated the system as Tropical Storm Iba.  The circulation around Tropical Storm Iba was still organizing.  Bands of showers and thunderstorms were developing and starting to revolve around the center of circulation.  Storms near the center of circulation were beginning to generate upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Iba will be in an environment favorable for intensification during the next 24 to 36 hours.  Iba will move over water where the Sea Surface Temperature is near 28°C.  It will move under the narrow eastern end of an upper level ridge.  The upper level winds right over Tropical Storm Iba will be relatively weak and there will not be significant wind shear.  Iba will likely strengthen during the next 24 to 36 hours.  There is a chance that Tropical Storm Iba could strengthen into a hurricane.

Tropical Storm Iba is in an area where the steering winds are weak.  Iba may drift slowly toward the south during the next day or so.  On its anticipated track Tropical Cyclone Iba will stay just off the coast of Brazil during the next 48 hours.