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Hurricane Season 2011: Tropical Storm 14S (South Indian Ocean)
02.11.11
 
AIRS showed strong convection (purple) and the strongest thunderstorms within 14S were in its eastern side. › View larger image
AIRS data showed strong convection (purple) and strongest thunderstorms within Tropical Storm 14S were in its eastern side. The AIRS instrument captured this infrared image on Feb. 11 at 06:41 UTC (1:41 a.m. EST). Australia is seen on the bottom right corner of the image.
Credit: NASA/JPL, Ed Olsen
Tropical Storm 14S Now a Remnant

Tropical Storm 14S ran into cool waters in the Southern Indian Ocean this weekend and quickly fizzled out, hundreds of miles west of Western Australia.

It weakened while moving almost directly westward and away from Australia on Saturday and Sunday Today, Feb. 14, the remnants can still be seen at about 22 South latitude and 90 degrees East longitude.

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












February 11, 2011

AIRS showed strong convection (purple) and the strongest thunderstorms within 14S were in its eastern side. › View larger image
AIRS data showed strong convection (purple) and strongest thunderstorms within Tropical Storm 14S were in its eastern side. The AIRS instrument captured this infrared image on Feb. 11 at 06:41 UTC (1:41 a.m. EST). Australia is seen on the bottom right corner of the image.
Credit: NASA/JPL, Ed Olsen
This visible image from AIRS clearly shows the circulation within the storm. › View larger image
NASA's Aqua satellite flew over Tropical Storm 14S on Feb. 11 at 06:41 UTC and the AIRS instrument captured this visible image. The image clearly shows the circulation within the storm.
Credit: NASA/JPL, Ed Olsen
NASA Satellite Sees Tropical Storm 14S Form in Southern Indian Ocean

Infrared data from NASA's Aqua satellite on Feb. 10 hinted that strong convection would likely make the low pressure area known as System 96S into the next tropical cyclone in the Indian Ocean. On Feb. 11, the same infrared data showed a well-developed, rounded area of thunderstorms and forecasters confirmed the low had become Tropical Storm 14S.

On Feb. 11 at 1500 UTC (10 a.m. EST), Tropical Storm 14S had maximum sustained winds near 35 knots (40 mph/64 kmh). It continued to move away from Western Australia and was at that time 620 miles west of Learmonth, Australia, near 20.6 South latitude and 103.1 East longitude. It was moving west-southwest near 18 knots (21 mph/33 kmh) and was generating 12-foot (~3.5 meter) high seas.

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured data that showed strong convection has developed closer to the low-level circulation center of the storm. The strongest thunderstorms within Tropical Storm 14S were in its eastern side. AIRS captured the infrared image on Feb. 11 at 06:41 UTC (1:41 a.m. EST). The strongest thunderstorms and strongest convection (rapidly rising air that condenses and forms the thunderstorms that power the tropical cyclone).

Strengthening is not expected over the weekend because Tropical Storm 14S is headed for cooler waters.

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













February 10, 2011

AIRS showed some strong convection and strong thunderstorms very cold cloud-top temperatures, in 96S. › View larger image
AIRS infrared image captured on Feb. 9 at 17:47 UTC (12:47 p.m. EST) showed some strong convection and strong thunderstorms (purple) with very cold cloud-top temperatures, around the center of System 96S.
Credit: NASA/JPL, Ed Olsen
NASA Infrared Satellite Data Gives System 96S a Fair Shot at Becoming a Tropical Cyclone

A low pressure area located a couple of hundred miles northwest of Western Australia appears in a better position for development into a tropical cyclone according to infrared NASA satellite imagery. Infrared imagery from NASA's Aqua satellite shows some strong convection in the low, named System 96S.

When Aqua passed over System 96S on Feb. 9 at 17:47 UTC (12:47 p.m. EST), the Atmospheric Infrared Sounder (AIRS) instrument showed some strong convection and strong thunderstorms with very cold cloud-top temperatures around the center of circulation. Those cloud top temperatures were as cold as or colder than -63 Fahrenheit/-52 Celsius indicating strong convection, strong thunderstorms, and heavy rainfall. The imagery suggests that the convection is consolidating and increasing around the low's center.

Convection is limited on the eastern half of System 96S because of moderate vertical wind shear (winds that can weaken a storm) blowing near 30 knots (34 mph/55 kmh)! That wind shear, however, is expected to weaken and enable the low to strengthen. Another factor that will help System 96S strengthen is the warm sea surface temperatures that it's located in. Sea surface temperatures are estimated near 30 degrees Celsius (86 Fahrenheit). Tropical Cyclones need sea surface temperatures of at least 26.6 Celsius (80 Fahrenheit) to maintain strength or intensify.

At 2300 UTC on Feb. 9, (6 p.m. EST) System 96S had maximum sustained surface winds near 20 to 25 knots (23 mph/ 37 kmh to 29 mph/46 kmh). It was located about 260 miles (418 km) northwest of Barrow Island, Australia near 17.7 South and 112.2 East. Residents of Western Australia are keeping a close eye on this system for development.

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