"Rainy days and Mondays" is the song that the residents of the northern Philippines do not want to hear if it involves the approaching Tropical Storm Songda. The Carpenters song was a hit, but a hit from Songda is making residents of the Philippines nervous as NASA's Aqua satellite has been watching the progression and intensification of the storm over the last several days.
In a series of three infrared images from the period of May 19-22, 2011, NASA's Atmospheric Infrared Sounder (AIRS) instrument revealed the strengthening of Tropical Storm Songda. The area with strongest convection has expanded and organized over that time. That area of strongest convection has the coldest, highest thunderstorm cloud tops near -63 F/-52C, and heaviest rainfall. The time series of imagery over those four days also shows that Songda took on a more rounded shape as it continued to strengthen from a tropical depression to a tropical storm. Today, May 23, satellite imagery shows a strong band of deep convection is persisting along the southern edge of Songda.
On May 21, Tropical Storm 04W still had maximum sustained winds near 40 mph (35 knots/64 kmh). On Sunday, May 22, the maximum sustained winds increased to 52 mph (45 knots/83 kmh) and the storm was renamed "Tropical Storm Songda." At that time the center of the storm was near 10.0 N and 136.4 E, or 190 miles north-northeast of Palau. By 2100 UTC on May 22, Songda's winds again increased to 55 knots as it continued moving north-northwest.
On May 23, Songda's maximum sustained winds have again increased and are now clocked at 69 mph (60 knots/111 kmh). Tropical storm-force winds extend out 100 miles (161 km) from the center. Further strengthening is expected by the forecasters at the Joint Typhoon Warning Center. Songda's center was located about 295 miles (475 km) northwest of Palau, near 11.5 North and 131.8 East, and it was moving west-northwest near 12 mph (10 knots/~18 kmh). Songda is kicking up high waves in the Northwestern Pacific, up to 22 feet (6/7 meters) high.
Songda is expected to continue intensifying over the next couple of days, but its center is forecast stay offshore from Luzon, Philippines and track east of land. However, the western side of the storm is expected to bring gusty winds, heavy rainfall and rough surf to Luzon over the next couple of days as it approaches and sweeps north toward Taiwan.
Explore further: NASA sees Tropical Storm 04W's thunderstorms grow quickly