Tropical Cyclone Felleng (South Indian Ocean)

Tropical Cyclone Felleng (South Indian Ocean)
01.28.13

AIRS image of Felleng› Larger image
NASA’s Aqua satellite passed over Tropical Storm Felleng on Jan. 28 at 4:29 a.m. EST and showed very cold cloud top temperatures (purple) and bands of thunderstorms wrapping around the center. Credit: NASA JPL, Ed Olsen NASA Satellites Analyze New Tropical Storm Felleng

NASA’s Aqua and Terra satellites have provided infrared imagery of Tropical Storm Felleng to forecasters. The imagery helped forecasters determine that Felleng would continue to intensify as it nears Madagascar.

Another tropical cyclone was born in the Southern Indian Ocean on Saturday, Jan. 26 as Tropical Storm 13S came together. On Sunday, Jan. 27 at 10 a.m. EST/U.S. (1500 UTC), Tropical Storm 13S was located at 13.7 South and 61.9 East, about 590 nautical miles (679 miles/1,093 km) northeast of La Reunion Island. Tropical Storm 13S was moving to the west-southwest at 11 knots (12.6 mph/20.3 kph). At that time, the low-level circulation center was partially exposed to outside winds. The strongest convection and heaviest rainfall was being pushed to the north of the center from southerly wind shear.

The MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard NASA’s Terra satellite captured an infrared image of Tropical Storm 13S on Jan. 27 at 1814 UTC (1:14 p.m. EST) that showed some strong thunderstorms around the center of circulation.

On Jan. 28, Tropical Storm 13S was renamed “Felleng.” La Reunion Island has also assigned “07/20132013” to the storm because it will be affected by Felleng on its track to the west.

NASA’s Aqua satellite passed over Tropical Storm Felleng on Jan. 28 at 0929 UTC (4:29 a.m. EST) and the Atmospheric Infrared Sounder (AIRS) instrument captured an image of the storm’s cloud top temperatures. AIRS observes in infrared light, which basically provides temperature information. In respect to tropical cyclones, the higher the thunderstorms (they’re made up of hundreds of thunderstorms), the colder the clouds, and the stronger the thunderstorms. AIRS data showed that cloud top temperatures around the center of Felleng were as cold as -63 Fahrenheit (-52 Celsius). Those strong storms are indicative of areas where heavy rain is falling.

AIRS imagery also showed that bands of thunderstorms were wrapped tightly around Felleng’s center indicating that the storm was well-organized. AIRS data also showed that the storm is symmetrical. A non-symmetrical storm usually weakens, while symmetrical storms have the potential to strengthen.

On Jan. 28 at 1500 UTC (10 a.m. EST), Felleng had maximum sustained winds near 45 knots (51.7 mph/83.3 kph). Tropical-storm-force winds extend about 60 nautical miles (69 miles/111 km) from the center. Felleng was located near 13.3 south latitude and 58.4 east longitude, about 500 nautical miles (576 miles/926 km) north-northeast of La Reunion Island. Felleng is moving to the west at 10 knots (11.5 mph/18.5 kph).

The Joint Typhoon Warning Center expects Tropical Storm Felleng to intensify over the next several days as it moves west. Felleng is expected to reach hurricane (cyclone) strength as it approaches Madagascar’s east coast, and then it is forecast to be pushed south by an approaching area of low pressure. Felleng is forecast to move south and travel between eastern Madagascar and La Reunion Island by Feb. 1.

Text Credit: Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.

One Comment

  1. Neville 29 January, 2013

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