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Hurricane Season 2008: Tropical Cyclone Higos (Pacific Ocean)
 
Oct. 3, 2008

Tropical Depression Higos Looking at Landfall on the China Coast

Satellite image of Higos Credit: NASA/JPL
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The Joint Typhoon Warning Center said in their statement on October 3, "[Tropical Depression] Higos is expected to maintain intensity as a weak tropical depression under marginally favorable conditions as the system steers towards Hainan Island and the southern Chinese coast. [Higos] will begin dissipating once making landfall on the Chinese mainland by [October 4]."

On Oct. 3, Tropical Depression Higos had sustained winds near 25 knots (28 mph) and was moving over Hainan Island, headed to mainland China. It was located near 19.3 degrees north latitude and 110.9 east longitude.

The image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was taken on Oct. 3 at 5:41 UTC (1:41 a.m. EDT). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it.

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. 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.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

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



Oct. 2, 2008

A Tale of Two Typhoons: One Terminating and One Toughening Up

AIRS image of Jangmi and Higos from Oct. 2, 2008
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Credit: NASA JPL
Former typhoon Jangmi is fading away in the western Pacific Ocean, while Tropical Depression Higos is expected to regain strength before making landfall in China.

On September 30, Tropical Cyclone Jangmi's remnants were drifting just south of Japan. By Oct. 2nd, The Joint Typhoon Warning Center, the organization that issues advisories for Typhoons, stopped issuing them for Jangmi, as it's now just a remnant low pressure area.

However, the latest advisory for Higos was issued on Oct. 2 at 1500 Zulu Time (11:00 a.m. EDT). At that time, Tropical Depression Higos had maximum sustained winds near 30 knots (34 mph). It was about 300 nautical miles east-southeast of Hainan Island, near 16.5 degrees north and 113.5 degrees east. Higos was moving westward at 16 knots (18 mph), and is expected to strengthen back into a tropical storm before making landfall on Hainan Island, China, late on Oct. 3. It is then expected to swing over and make landfall around 65 miles west of Hong Kong and follow the China coast on a northeast path before fizzling on Oct. 7 between Hong Kong and Shanghai.

Aqua Satellite Sees Both Storms' Cold Clouds

The image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was taken on Sept 30 at 17:23 UTC (1:23 p.m. EDT). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it. In the image, Jangmi's remnants are in the top right corner, while Higos is in the lower left corner, centered over the Philippines.

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. 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.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters. Text credit: Rob Gutro/Goddard Space Flight Center


Sept. 30, 2008

Tropical Cyclone 21W Now Named Higos; Raining on the Philippines

Satellite image of Higos Credit: NASA/JPL
> Larger image
Tropical Cyclone 21 W in the western Pacific Ocean has finally been given a name. It's now called "Higos." Higos is now poised to make landfall in the eastern Philippines today, Sept. 30, then track over Manila and head toward Hong Kong.

On Sept. 30 at 6:00 Zulu Time (2:00 a.m. EDT), Tropical Storm Higos, formerly 21W, was located 325 nautical miles east-southeast of Manila, the Philippines. That's near 12.0 degrees north latitude and 126.0 degrees west longitude. Higos' maximum sustained winds increased from 35 knots (40 mph) to 45 knots (52 mph) and Higos was moving northwestward near 14 knots (16 mph).

Higos is the international codename for the storm, and the Philippine Weather Service (PWS) is referring to the storm in local advisories as "Pablo." The PWS has already posted a "Public Storm Signal 2," for Catanduanes, Sorsogon, Albay, Masbate, Ticao Island, and Burias Island in Luzon as well as in the Samar Provinces, Leyte, and Biliran island in Mindanao. Where a storm signal 2 has been issued, residents in coastal areas should expect big waves and storm surges.

Aqua Satellite Sees Higos's Cold Cloud Temperatures

This infrared image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. It was taken on Sept. 29 at 12:41 p.m. EDT (16:41 UTC). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it. The image shows that Higos' clouds stretch from the southeastern Philippines far to the east into the open western Pacific Ocean waters.

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. 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.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

Text credit: Rob Gutro (from Joint Typhoon Warning Center reports), NASA's Goddard Space Flight Center