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Hurricane Season 2009: Tropical Storm Goni (Western Pacific)
08.06.09
 
August 6, 2009

NASA Satellite Sees Goni's Remnants Still Soaking Southeast China

This NASA AIRS infrared satellite image shows the remnants of tropical cyclone Goni's  clouds and rains over southeast China. > View larger image
This NASA AIRS infrared satellite image shows the remnants of tropical cyclone Goni's clouds and rains over southeast China (depicted in blue).
Credit: NASA/JPL, Ed Olsen
Although Tropical Storm Goni is "gone" as a tropical cyclone, its remnants are still bringing rains to southeast China.

When Goni made landfall, it brought heavy rains to Taishan, located in south China's Guangdong Province. That province reporter up to 400 millimeters (15.75 inches) of rain and more rain is expected today, August 6 and Friday, August 7 as the remnants continue moving slowly westward. The Fujian Province located next to Guangdong, also reported heavy rainfall.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite and captured an image of Goni's remnants on August 5 at 1:41 p.m. EDT. AIRS measures cloud top temperature and air pressure in tropical cyclones, and although Goni isn't a tropical cyclone anymore, its rains will continue to be felt for another day or two.

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



August 5, 2009

Goni…Goni…Gone as It Dissipates Over Inland China

This AIRS image from the Aug. 4 showed the fringes of then Tropical Storm Goni already raining over coastal southeast China. > View larger image
This AIRS image from the Aug. 4 showed the fringes of then Tropical Storm Goni already raining over coastal southeast China. The center of the storm was still in the South China Sea, northeast of Hainan Island. It made landfall late that night
Credit: NASA/JPL, Ed Olsen
Tropical Cyclone Goni made landfall late last night, August 4 south of Hong Kong, China, and is now dissipating over land.

Goni, now a tropical depression, was located about 95 nautical miles west-southwest of Hong Kong near 22.0 north and 112.3 east according to the last advisory issued at 10 p.m. EDT on Aug. 4 by the Joint Typhoon Warning Center. The remnant was still moving westward near 6 mph and had maximum sustained winds near 28 mph.

NASA's Aqua satellite flew over Goni and the Atmospheric Infrared Sounder (AIRS) instrument onboard captured an infrared image on Aug. 4 at 2:35 p.m. EDT. The AIRS image showed the fringes of then Tropical Storm Goni already raining over coastal southeast China and the center of the storm was still in the South China Sea, northeast of Hainan Island.

Infrared imagery is useful to forecasters because it shows the temperature of the cloud tops, facilitating the recognition of deep convective cells. NASA false-colors clouds at different heights in the infrared satellite images, so that the highest clouds appear purple, and the second highest clouds appear in blue. The highest clouds and heaviest rains at the time of the image were still over the open sea, and moved inland in the hours that followed.

Goni is expected to dissipate over land today.

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



August 4, 2009

Tropical Depression 08W Becomes Tropical Storm Goni Near China

NASA's Terra satellite captured Tropical Storm Goni on August 4 using infrared imagery from the MODIS instrument. > View larger image
NASA's Terra satellite captured Tropical Storm Goni on August 4 using infrared imagery from the Moderate Imaging Spectroradiometer (MODIS) instrument, and showed a pretty well organized tropical storm of the southeastern China coast.
Credit: NASA, MODIS Rapid Response
On August 4, Tropical Depression 08W has strengthened and has been given the name Goni as it is poised for a landfall in southeast China. The forecast track has changed bringing Goni further south for a landfall south of Hong Kong later today or tomorrow.

At 2 a.m. EDT, Goni's center was located only 70 miles south-southwest of Hong Kong, China, near 21.1 north and 113.8 east and has been moving northwest at 6 knots (7 mph). Goni's sustained winds have increased to 40 knots (46 mph), with higher gusts. Hong Kong is already feeling the fringe effects of Tropical Storm Goni's winds, and seeing high surf along the coast.

There are a couple of things happening with Tropical Storm Goni that will likely prevent it from strengthening too much before it makes landfall. First, the center of circulation on the surface is partially exposed. That means that it's open to weakening from influence of outside winds. Secondly, Tropical Storm Goni is being battered by 20 knot (23 mph) vertical wind shear (winds that can tear a storm apart). However, in the South China Sea where Goni is currently located, warm waters continue to fuel the tropical cyclone. Goni is churning up 16 foot-high seas, so mariners in southeastern China have been warned not to venture out.

NASA's Terra satellite flew over Tropical Storm Goni on August 4 at 03:20 UTC (11:20 p.m. EDT), and using infrared imagery from the Moderate Imaging Spectroradiometer (MODIS) instrument, captured a pretty well organized tropical storm of the southeastern China coast. Landfall is expected late today or tomorrow morning, and will be accompanied by heavy rains, heavy surf conditions along the coast and gusty winds.

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



August 3, 2009

Deadly Tropical Depression Eight-W Now Headed To Southern China

NASA's AIRS instrument captured TD#8W's cold clouds over the northern Philippines on July 31 at 1:11 a.m. > View larger image
NASA's AIRS instrument captured TD#8W's cold clouds over the northern Philippines on July 31 at 1:11 a.m. EDT, when it was bringing heavy rains and gusty winds. The purple and blue areas are the coldest, highest clouds with the heaviest rains.
Credit: NASA/JPL, Ed Olsen
NASA's AIRS instrument captured TD#8W's cold clouds Aug. 3 at 1:47 a.m. > View larger image
NASA's AIRS instrument captured TD#8W's cold clouds Aug. 3 at 1:47 a.m. EDT raining on China's Hainan Island and Vietnam. The purple and blue areas are the coldest, highest clouds with the heaviest rains.
Credit: NASA JPL, Ed Olsen
Tropical Depression Eight-W was given the name "Jolina" by Philippine meteorologists as it brought heavy rains and gusty winds to several regions there this past weekend. Several people died from mudslides and floodwaters. Now it's headed for a landfall mid-week in southern China, just north of Hong Kong.

On Saturday, August 1, "system 93W" now Tropical Depression 8-W (TD#8W) formed near 15.5 north latitude and 123.1 east longitude, about 140 miles east-northeast of Manila, Philippines. The Philippine Weather Service "PAGASA" issued a Tropical cyclone formation alert and called the storm "Jolina." PAGASA always provide their own names for storms that affect the Philippines.

The storm's heavy rains caused flooding and mudslides and took eight lives over the weekend. The storm affected more than 100,000 people in the Central Luzon, Mimaropa, Bicol and Soccsksargen Regions of the Philippines and there was a mass evacuation in the provinces of Sultan Kudarat and Maguindanao because of heavy rains and high floodwater levels.

Satellite imagery from NASA's Aqua satellite, that carries the Atmospheric Infrared Sounder (AIRS) shows that the storm is expanding in area. Infrared imagery is useful to forecasters because it shows the temperature of the cloud tops, facilitating the recognition of deep convective cells. NASA false-colors clouds at different heights in the infrared satellite images, so that the highest clouds appear purple, and the second highest clouds appear in blue. How does infrared imagery know how high clouds are in the sky? The coldest ones are higher in the sky (because in the troposphere, the lowest layer of atmosphere where weather happens, temperatures fall the higher up you go until you get to the stratosphere).

In infrared imagery, NASA's false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone.

On Monday, August 3 at 11 a.m. EDT (1500 Zulu Time), TD#8W was located about 160 nautical miles south-southeast of Hong Kong, or near 20.1 north and 115.4 east. It was tracking north at 9 mph with sustained winds near 30 knots (34 mph).

The Joint Typhoon Warning Center is forecasting that TD#8W "Will continue to track north-northwestward, maintain intensity, then weaken and make landfall north of Hong Kong by 11 a.m. EDT on August 5.

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