On October 9, 2012, two days after forming over the Pacific Ocean, Prapiroon strengthened into a typhoon. It retained at typhoon strength on October 15, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image. Prapiroon’s spiral arms stretched over Okinawa, Japan.
The same day that MODIS acquired this image, the U.S. Navy’s Joint Typhoon Warning Center (JTWC) reported that Prapiroon had maximum sustained winds of 70 knots (130 kilometers per hour) and gusts up to 85 knots (155 kilometers per hour). These wind speeds were down from those reported several days earlier, but Prapiroon remained a strong storm, centered about 305 nautical miles (565 kilometers) southeast of Kadena Air Base in Okinawa.
On October 15, the JTWC projected storm track for Prapiroon showed the storm moving roughly northward over the western Pacific Ocean then turning toward the northeast and following a path roughly parallel to the Japanese island of Honshu.