May 25, 2011
NASA’s Infrared Satellite Imagery Shows A Stronger Typhoon Songda
Songda is now a typhoon in the Northwestern Pacific Ocean as it continues tracking parallel to the eastern coast of Luzon, Philippines. Infrared satellite imagery from NASA's Aqua satellite revealed that the storm has a much tighter low-level circulation center than it did yesterday.
NASA's Aqua satellite passed over Typhoon Songda on May 24 at 04:29 UTC (12:49 a.m. EDT) and the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared look at the storm's cloud top temperatures and warm waters surrounding it.
AIRS infrared imagery shows that the thunderstorm cloud tops around the low-level center are cooling and consolidating. The rule in infrared imagery with thunderstorms is that the colder the cloud top temperature, the higher the thunderstorm and the stronger it is. Cloud-top temperatures in today's imagery are as cold as -63 Fahrenheit/-52 Celsius indicating strong storms that are heavy rainmakers. The AIRS imagery also showed that the convection (rapidly rising air that forms thunderstorms) was not symmetrical as the strongest thunderstorms were mostly over the southern part of the semicircle.
At 1500 UTC (11 a.m. EDT) on May 24, Songda (known as Chedeng in the Philippines) was about 500 nautical miles (575 miles/926 kilometers) east-southeast of Manila, Philippines near 12.6 North and 129.3 East. It was moving west-northwest near 9 knots (10 mph/17 kmh) and its maximum sustained winds had increased to 65 knots (75 mph/120 knh). Tropical-storm force winds extend out to 105 miles (169 km) from the center, so the storm has expanded a little since yesterday. As Songda has strengthened so has its generation of rough surf. Songda is now generating waves up to 26 feet (8 meters) high.
Two warnings are in effect in the Philippines, Public storm warning signal no 2 is in effect for the Luzon province of Catanduanes. Public storm warning signal no 1 is in effect for the following provinces: in Luzon for: Sorsogon, Burias island, Ticao island, Albay, Camarines Sur & Norte, and in Visayas for the Samar provinces
The sea surface temperatures in the vicinity of the typhoon are warm and wind shear is low, both of which will enable Songda to strengthen further as it curves to the north.
Image Caption: NASA's Aqua satellite passed over Typhoon Songda earlier today, May 24, at 04:29 UTC and the infrared imagery from the Atmospheric Infrared Sounder (AIRS) instrument revealed stronger thunderstorms (purple) near its low-level center. Credit: NASA JPL, Ed Olsen
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