Tropical Depression 15W intensified during the early morning hours of September 12 and became a tropical storm re-named "Kalmaegi." NASA's Aqua satellite passed overhead as the storm intensified.
The MODIS instrument, known as the Moderate Resolution Imaging Spectroradiometer that flies aboard NASA's Aqua satellite captured a visible image of Tropical Storm Kalmaegi approaching the Philippines on Sept. 12 at 4:45 UTC (12:45 a.m. EDT). The image showed tightly-curved bands of thunderstorms over the northern and southern quadrants of the storm that were wrapping into a consolidating low-level center. The consolidation of the center and the banding of thunderstorms are conducive to a strengthening storm, and forecasters expect Kalmaegi to continue strengthening over the next couple of days.
On Friday, September 12 at 0900 UTC (5 a.m. EDT) Tropical Storm Kalmaegi's maximum sustained winds were near 40 knots (46 mph/74 kph). Kalmaegi was centered near 13.8 north latitude and 130.2 east, about 572 nautical miles (658.2 miles/1,059 km) east of Manila, Philippines. Kalmaegi was moving to the west at 14 knots (16.1 mph/25.9 kph).
Forecasters at the Joint Typhoon Warning Center forecast Kalmaegi to become a typhoon (same thing as a hurricane, but west of the International Date Line) by September 13. Kalmaegi is forecast to cross Luzon, the northern Philippines, from southeast to northwest on September 14 before entering the South China Sea and heading for another landfall south of Hong Kong.
Rob Gutro
NASA's Goddard Space Flight Center