NASA MODIS Image of the Day: August 9, 2011 – Typhoon Muifa (11W) and Tropical Storm Merbok (12W) in the western Pacific
In one image, NASA’s Aqua satellite captured two tropical cyclones in the western North Pacific in early August 2011.
The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua satellite captured Typhoon Muifa near Okinawa, Japan and Tropical Storm Merbok farther east in the western Pacific at 4:35 UTC (12:35 a.
m. EDT) on August 5, 2011. By having the storms side-by-side in one image, it is much easier to see how Merbok is much less organized than the more powerful Muifa. Muifa also has an eye, although cloud-filled, whereas Merbok does not. On August 5, Typhoon Muifa’s maximum sustained winds were near 80 knots, and typhoon-force winds extended out to 70 miles from the center. Tropical storm-force winds went much farther, out to 220 miles from the center, making Muifa a monster storm of about 440 miles in diameter. Typhoon Muifa formed as a low pressure area on July 23, drifting west until it became a tropical depression. At that time, it turned north and rapidly strengthened to a Category 5 Super Typhoon as it neared the Philippines, where it caused substantial damage and claimed eight lives. Muifa weakened as it drifted north then west, and then poured 41 inches of rain on Okinawa, Japan. As of 4:00 UTC on August 8 (midnight on August 9 in Seoul), Muifa made landfall over North Korea. The storm was downgraded to a tropical depression shortly after landfall, but still brought torrential rains to northeast China as it moved inland. Merbok was first identified as a tropical depression on August 3 by the Japan Meteorological Agency (JMA). It rapidly intensified and only 6 hours later became Tropical Storm Merbok. By August 5 the storm became a Severe Tropical Storm, and the next day the Joint Typhoon Warning Center upgraded Merbok to Category 1 Typhoon. At that time, it was located 1,540 km (960 mi) east-southeast of Tokyo Japan. On August 7, the storm’s one-minute sustained winds reached 150 km/h (92 mph) before it ran into vertical wind shear and started weakening. The JTWC issued the last advisory on Merbok late on August 8. At that time, the storm was forecast to continue tracking northeastward, but was expected to slow slightly as it completes extra-tropical transition and occludes.
