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Hurricane Season 2012: Tropical Storm Cyril (Southern Pacific Ocean)
02.09.12
 
Feb. 9, 2012

AIRS captured this infrared image of the remnants of Cyril on February 8, 2012 at 1135 UTC (6:35 a.m. EST). › View larger image
The AIRS instrument on NASA's Aqua satellite captured this infrared image of the remnants of Tropical Depression Cyril on February 8, 2012 at 1135 UTC (6:35 a.m. EST). The cloud tops had warmed (blue) and fallen in height, and there were no strong thunderstorms in the weakened circulation.
Credit: NASA/JPL, Ed Olsen
NASA Infrared Image Sees Cyclone Cyril Dissipating

The punch has quickly gone out of Tropical Cyclone Cyril as colder sea surface temperatures and strong wind shear have dissipated the system. NASA's Aqua satellite captured warming cloud top temperatures which indicated the storm weakened fast over the last day.

One last image of Cyril was captured by the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite on February 8, 2012 at 1135 UTC (6:35 a.m. EST). The cloud tops had warmed quickly from the previous day and they had fallen in height. That means that there was little strength left to carry the thunderstorms high into the troposphere. The higher the thunderstorm, the stronger the storm, and there was no sign of strength in the AIRS infrared image. Cyril's remnants have now dissipated in the Southern Pacific Ocean.

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





Feb. 7, 2012

This infrared image was taken from the AIRS instrument on NASA's Aqua satellite, on February 7, 2012 at 12:29 UTC. › View larger image
This infrared image was taken from the AIRS instrument on NASA's Aqua satellite, on February 7, 2012 at 12:29 UTC. Cyril is still a very compact, rounded storm. The strongest thunderstorms remain close to the center of circulation (purple) where cloud top temperatures are below -63 F (-52.7C).
Credit: NASA/JPL, Ed Olsen
NASA Satellite Sees Tropical Storm Cyril a Strong, Compact Storm

Tropical Storm Cyril was known as "11P" has been strengthening since February 6, and still appears very compact on infrared NASA satellite data.

In the morning hours of February 7 (local time Vanuatu) Cyril was located south of the island of Vavau in the Kingdom of Tonga. All warnings for Niue and Tonga have now been cancelled.

During the morning hours of February 7, Cyril picked up speed and is moving to the southeast at 28 knots (~32 mph/~52 kph). Cyril's maximum sustained winds were near 45 knots (~52 mph/~83 kph). Those tropical-storm-force winds only extended out to 35 miles (~56 km), making the storm over 70 miles (~113 km) in diameter. Satellite imagery from February 6 helped forecasters estimate that the clouds associated with Cyril extended to 120 miles in diameter.

By 1500 UTC on February 7 (10 a.m. EST or 4 a.m. on Feb. 8 Pacific/Tongatapu local time) Cyril was centered about 545 nautical miles (627 miles/1,009 km) south of Pago Pago, American Samoa near 23.8 South and 165.0 West. Cyril covered 175 nautical miles (~196 miles/~315 km) in 12 hours during the morning hours of February 7.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of Cyril's clouds on February 7, 2012 at 12:29 UTC. Cyril still appears as a very compact, rounded storm. The strongest thunderstorms remained close to the center of circulation where cloud top temperatures are below -63 F (-52.7C).

The Australian Broadcasting Corporation noted that the Vavau airport reported sustained winds of 45 knots (~52 mph/~83 kph) on Feb. 8 at 6:30 a.m. local Pacific/Tongatapu time.

As Cyril continues to speed to the southeast, the vertical wind shear is forecast to increase and sea surface temperatures are expected to be much cooler. In fact, water temperatures will decrease to 25 degrees Celsius (77F) and colder. Sea surface temperatures must be at least 26.6C (80F) to support a tropical cyclone, otherwise the system begins to weaken. The Joint Typhoon Warning Center gives Cyril two days before it dissipates.

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



Feb. 6, 2012

AIRS captured this image of Tropical Storm 11P on February 6, 2012 at 0053 UTC. › View larger image
NASA's Aqua satellite captured this image of Tropical Storm 11P, on February 6, 2012 at 0053 UTC. AIRS infrared data from Aqua showed strong thunderstorms with the highest, coldest cloud tops circling the center (purple).
Credit: NASA/JPL, Ed Olsen
NASA's Aqua Satellite Sees Small New Tropical Storm Near Tonga

Tropical Storm 11P has formed in the South Pacific Ocean, and NASA's Aqua satellite captured an infrared image of its cloud temperatures, revealing power in the cyclone.

NASA's Atmospheric Infrared Sounder (AIRS) instrument that flies aboard the Aqua satellite passed over the newest tropical storm in the South Pacific, Tropical Storm 11P, on February 6, 2012 at 0053 UTC (Feb. 5 at 7:53 p.m. EST). AIRS infrared data showed strong thunderstorms with the highest, coldest cloud tops circling the center. The cloud top temperatures were colder than -63 Fahrenheit (-52.7 Celsius), indicating that some of the thunderstorms were strong. The AIRS data also showed that the storm is small, about 120 nautical miles (138 miles/222 km) in diameter, and there are bands of thunderstorms wrapping into the center of circulation.

On February 6, 2012 at 1500 UTC (10 a.m. EST), Tropical Storm 11P had maximum sustained winds near 35 knots (40.2 mph/64.8 kph). It was about 400 nautical miles (460 miles/~741 km) east of Nadi, Fiji, centered near 18.8 South latitude and 174.5 West longitude. It was moving quickly at 21 knots (~24 mph/~39 kph) to the east-southeast.

Tropical Storm 11P is approaching the main island of Tonga late on February 6. Tonga is a state and an archipelago made up of 176 islands, fifty-two of which are inhabited. It is expected to pass northeast of the main island, Tongatapu.

The Joint Typhoon Warning Center expects Tropical Storm 11P (TS11P) to speed up to the east-southeast to as fast as 30 knots (34.5 mph/55.5 kph). By February 7, TS11P is expected to encounter wind shear and cooler sea surface temperatures, two factors that will weaken it quickly. Forecasters expect that by February 9, the tropical storm will be a remnant low pressure area.

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