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Tropical Cyclone Fantala Gets Bigger and Stronger

Tropical Cyclone Fantala grew in size and intensity on Wednesday.  At 8:00 p.m. EDT on Wednesday the center of Tropical Cyclone Fantala was located at latitude 12.7°N and longitude 64.2°E which put it about 700 miles (1130 km) northeast of Port Louis, Mauritius.  Fantala was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 956 mb.  The Hurricane Intensity Index (HII) was 17.8, the Hurricane Size Index (HSI) was 14.6 and the Hurricane Wind Intensity Size Index (HWISI) was 32.4.

Both the organization and size of the circulation of Fantala increased on Wednesday.  A complete eyewall formed around an eye at the center of the tropical cyclone.  Other well formed bands of thunderstorms developed and wrapped around the core of Fantala.  The structure of the tropical cyclone is much more symmetrical and there are thunderstorms in all quadrants of the circulation.  Winds to hurricane force extended out 35 miles (55 km) from the center of circulation.  Thunderstorms around the core of Fantala generated upper level divergence which pumped out mass and allowed the surface pressure to decrease.

Tropical Cyclone Fantala is an environment favorable for further intensification.  Fantala is over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and there is very little vertical wind shear.  The structure of Fantala will allow it to use the energy from the ocean very efficiently.  Fantala is likely to continue to intensify on Thursday and it could become the equivalent of a major hurricane.  As Fantala gets stronger, concentric eyewalls could develop and the resulting eyewall replacement cycles could produce fluctuations in intensity.

A subtropical ridge located to the south of Fantala is steering it toward the west and that general steering motion is expected to continue during the next several days.  On its anticipated track Fantala will pass north of Mauritus and La Reunion during the weekend.  Tropical Cyclone Fantala could be near northern Madagascar in a few days.

Tropical Cyclone Fantala Intensifies and Heads Slowly West

Tropical Cyclone Fantala intensified into the the equivalent of a hurricane/typhoon as it headed slowed west across the South Indian Ocean on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Fantala was located at latitude 12.8°S and longitude 68.5°E which put it about 465 miles (755 km) south-southwest of Diego Garcia.  Fantala was moving toward the west-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 975 mb.

The core of Tropical Cyclone Fantala continued to get better organized on Tuesday.  The primary rainband wrapped entirely around the center of circulation and a small eye appeared intermittently on some satellite imagery.  Thunderstorms around the center of circulation began to produce more upper level divergence and high clouds could be seen fanning out in all directions.  The upper level divergence pumped out mass and allowed the surface pressure to decrease.

Fantala is a small tropical cyclone.  Tropical storm force winds only extend about 100 miles (160 km) from the center of circulation.  The Hurricane Size Index for Tropical Cyclone Fantala is only 8.1.

Tropical Cyclone Fantala is in an environment that appears to be mostly favorable for intensification.  It is over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and there is not much vertical wind shear.  The only possible negative factor is the presence of some drier air around the periphery of the circulation.  Tropical Cyclone Fantala is likely to intensify further and its small size could allow it to intensify rapidly at times.  Tropical Cyclone Fantala could become the equivalent of a major hurricane later this week.

A subtropical ridge located south of Fantala is steering the tropical cyclone toward the west and that general motion is expected to continue for the next several days.  On its anticipated track Tropical Cyclone Fantala could pass north of La Reunion in a few days.  Fantala could be northeast of Madagascar in four or five days.

Tropical Cyclone Fantala Forms South of Diego Garcia

A well organized center of circulation developed within a small area of thunderstorms south of Diego Garcia on Monday and the system was designated Tropical Cyclone Fantala.  At 8:00 p.m. EDT on Monday the center of Tropical Cyclone Fantala was located at latitude 13.0°S and longitude 70.8°E which put it about 420 miles (675 km) south-southwest of Diego Garcia.  Fantala was moving toward the west at 9 m.p.h. (14 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 989 mb.

The circulation of Tropical Cyclone is still organizing.  A primary rainband is wrapping around the southern and western sides of the center of circulation.  Most of the thunderstorms are near or in the primary rainband.  There are few thunderstorms east of the center of circulation.  The thunderstorms are generating upper level outflow to the west side of the circulation.

The environment is favorable for further intensification.  Fantala is over water where the Sea Surface Temperatures are near 30°C.  An upper level ridge south of Fantala is generating light easterly winds over the core of the circulation.  The easterly winds are producing a little vertical wind shear.  The shear is strong enough to contribute to the asymmetrical distribution of thunderstorms, but it is not strong enough to prevent intensification.  Tropical Cyclone Fantala could become the equivalent of a hurricane/typhoon within 24 hours.

A subtropical ridge south of Fantala is expected to steer the tropical cyclone in a general westerly direction during the next few days.  On its anticipated track Tropical Cyclone Fantala could be northeast of La Reunion later this week.