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Hurricane Season 2009: Tropical Cyclone Freddy (Indian Ocean)
Feb. 11, 2009

Freddy's Dead…Just Like the Old Song

Tropical Cyclone Freddy fading on Feb. 10 Credit: NASA JPL, Ed Olsen
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Tropical Cyclone Freddy was in the Southern Indian Ocean early in the week of February 8th, but now as the 1972 song from Curtis Mayfield goes, "Freddy's Dead."

That song was featured in a soundtrack album for the film Super Fly, and it peaked at #4 on the U.S. pop music charts. The song laments the death of a character in the film that was run over by a car. Fortunately, the only thing Cyclone Freddy ran over was the open waters of the Indian Ocean.

NASA's Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured this visible image of Freddy on Feb. 10 at 6:59 UTC (1:59 a.m. EST) as it was rapidly fading away in open waters.

The low pressure area that was once Freddy was last identified on Feb. 9 near 19.3 degrees south latitude and 103.5 degrees east longitude. That's about 615 miles west-northwest of Learmonth, Northwest Australia, in the open Indian Ocean. At that time, Freddy's winds were around 45 knots (52 mph), but he quickly encountered an unfavorable environment and lost his tropical storm-force winds. In essence, "Freddy's dead."

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

Feb. 09, 2009

Freddy Frolics in Open Waters West of Australia

satellite image of Freddy Credit: NASA/JPL
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Tropical Cyclone Freddy formed over the weekend of February 7-8 in the open waters of the Indian Ocean northwest of northwestern Australia, and he'll stay at sea. Freddy won't bring any relief to the areas of Australia that are being ravaged by severe fires and a heatwave. In Australia's Queensland region, residents there hope not to see another tropical cyclone as they are still reeling from flooding.

On Monday, February 9, 2009 at 0600 Zulu Time (1 a.m. EST), Freddy was 525 nautical miles west-northwest of Learmonth, Australia. That's near 18.5 south and 105.1 east. Freddy was packing sustained winds near 40 knots (46 mph) with higher gusts, and moving southwestward near 13 knots (15 mph). Freddy is expected to continue in that general direction, where it will encounter cooler waters and a persistent easterly vertical wind shear (winds that can tear a storm apart). That means Freddy's life is expected to be cut short this week.

NASA's Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite captured this image of Freddy on Feb. 8 at 18:05 Zulu Time (12:47 a.m. EST). AIRS generates infrared, microwave and visible images. The AIRS infrared data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

Because the AIRS infrared signal doesn't penetrate through clouds AIRS reads the infrared (heat) signal from the ocean and land surfaces where there are clear skies. Those warm ocean and land temperatures are false-colored in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are). Looking at the satellite image, you can see that the shade of orange in the ocean waters to Freddy's southwest are not as dark, indicating cooler waters. Because Freddy is headed into that direction, that's one of the reasons he'll be weakening soon.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

Feb. 06, 2009

Western Australia's Waters Give Birth to Tropical Cyclone 14S

AIRS image of Tropical Storm 14S.> Larger image
Credit: NASA/JPL
This has been one very busy cyclone/hurricane season for Australia, and its not letting up. Tropical Cyclone 14S formed at sea today, Feb. 6, some 375 miles north of Learmonth, but its going to stay at sea.

At 1500 UTC (10 a.m. EST) on Feb. 6, Tropical Cyclone 14S had sustained winds near 30 knots (34 mph) and will soon likely get a name as it is forecast to slowly intensify. It was located near 16.0 degrees south latitude and 113.1 degrees east longitude. 14S is moving west into the open waters of the Indian Ocean and away from land.

The sharp contrast in temperatures from the frigid cloud tops in Cyclone 14S to the scorching earth of southern Australia is evident in this infrared image from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite. AIRS captured this image of 14S on Feb. 6 at 05:47 Zulu Time (12:47 a.m. EST).

The infrared image clearly shows a large temperature difference between 14s' cloudtops and the warm land temperatures in southern Australia (in red). Southern regions in Australia have recently been experiencing a heatwave with temperatures near 100 degrees Fahrenheit. In this image, the orange temperatures are 80F (300 degrees Kelvin) or warmer. The red areas that cover much of southern Australia are around 310 degrees Kelvin, or 98 degrees Fahrenheit or hotter!

In Cyclone 14S, the lowest temperatures (in purple) are associated with high, cold cloud tops. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

Text credit: Rob Gutro, NASA Goddard Space Flight Center