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Hurricane Season 2011: Tropical Storm Merbok (Western North Pacific Ocean)
08.08.11
 
Tropical Storm Merbok moving through the western North Pacific Ocean on August 7 at 02:41 UTC. › View larger image
NASA's Aqua satellite captured this visible image of Tropical Storm Merbok moving through the western North Pacific Ocean on August 7 at 02:41 UTC. Most of the convection and thunderstorms were on the northeastern side of the storm (purple and blue). Merbok was over 800 hundred miles east of Japan (left).
Credit: NASA Goddard MODIS Rapid Response
Comma-Shaped Tropical Storm Merbok Transitioning on NASA Image

An infrared instrument on NASA's Aqua satellite noticed that Tropical Storm Merbok appeared comma-shaped today, and is making the transition into an extra-tropical storm.

When NASA's Aqua satellite flew over Tropical Storm Merbok on August 7 at 02:41 UTC (August 6 at 10:41 p.m. EDT) it took an infrared image of the storm's cloud temperatures. The infrared image was taken by the Atmospheric Infrared Sounder instrument.

It showed that most of the convection (rapidly rising air that forms thunderstorms that make up the tropical storm) were on the northern half of the system, giving it more of a comma-shaped appearance. Those thunderstorms also had high cloud tops that measured a chilly -63 Fahrenheit/-52 Celsius. On the southeastern side, convection and thunderstorms were pushed away from the low-level center of circulation, indicating wind shear was weakening it.

At 1500 UTC (11 a.m. EDT) on August 8, Tropical Storm Merbok's maximum sustained winds were near 55 knots (63 mph/101 kmh). It was located 840 nautical miles east-northeast of Yokosuka, Japan, near 27.4 North and 159.1 East. It was moving to the northeast near 18 knots (21 mph/33 kmh) and remaining at sea. Merbok is not threatening any land areas is it transitions into an extra-tropical storm.

Text credit: Rob Gutro, NASA Goddard Space Flight Center, Greenbelt, Md.



August 5, 2011

MODIS captured Muifa and Merbok in the western Pacific at 4:35 UTC (12:35 a.m. EDT) on August 5, 2011. › View larger image
NASA's Aqua satellite captured Typhoon Muifa and Tropical Storm Merbok in the western Pacific at 4:35 UTC (12:35 a.m. EDT) on August 5, 2011. Muifa is almost twice as large as Merbok.
Credit: NASA Goddard MODIS Rapid Response
NASA Sees Typhoon Muifa Almost Twice as Big as Tropical Storm Merbok

In one image, NASA's Aqua satellite captured two tropical cyclones in the western North Pacific today, Tropical Storm Merbok and the large Typhoon Muifa. NASA Satellite imagery shows that Muifa is almost twice as big as Merbok.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's 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 a lot 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.

Muifa was only 45 nautical miles southwest of Kadena Air Force Base, Japan this morning (August 5) at 5 a.m. EDT, pounding the island with heavy rains, typhoon-force winds and very rough surf. Its center was near 25.8 North and 127.2 East and it was moving to the northwest near 7 knots (8 mph). By 8 a.m. EDT, Muifa's center had moved past Kadena and was located 55 nautical miles west-southwest of the island.

The maximum significant wave heights are reaching 36 feet creating extremely hazardous seas. Muifa is expected to recurve to the northwest or north and skirt the east coast of China and make landfall in Korea.

Tropical storm Merbok is not a threat to land areas, and is moving around in the open waters of the North Pacific. It is located 675 miles west-northwest of Wake Island near 26.8N and 155.3E. Merbok's maximum sustained winds are near 50 knots, and tropical-storm force winds extend 120 miles from the center, making the storm 240 miles in diameter. Merbok is moving to the north-northwest at 8 knots and creating 21-foot high waves.

Merbok is strengthening as it moves northwest and is expected to make typhoon strength before weakening and curving northeast.

Text credit: Rob Gutro, NASA Goddard Space Flight Center, Greenbelt, Md.



August 4, 2011

AIRS infrared image of Tropical Storm Merbok on August 3 at 15:11 UTC. › View larger image
NASA's Aqua satellite passed over Tropical Storm Merbok in the western North Pacific Ocean on August 3 at 15:11 UTC (11:11 a.m. EDT) This infrared image was taken from the AIRS instrument on NASA's Aqua satellite and it revealed a compact, rounded center of very cold cloud top temperatures (purple) from strong thunderstorms.
Credit: NASA/JPL, Ed Olsen
NASA Sees Compact Tropical Storm Merbok

The twelfth tropical cyclone of the western North Pacific Ocean season formed into a tropical storm on August 3 and NASA satellite imagery shows it to be a compact and rounded storm.

NASA's Aqua satellite passed over Tropical Storm Merbok in the western North Pacific Ocean on August 3 at 15:11 UTC (11:11 a.m. EDT). The Atmospheric Infrared Sounder (AIRS) instrument on Aqua took an infrared image and it revealed a compact, rounded center of very cold cloud top temperatures (as cold as -63 Fahrenheit/-52 Celsius) from strong thunderstorms. The AIRS image also showed a number of bands of thunderstorms surrounding the center, which indicates organization.

Tropical storm Merbok has maximum sustained winds near 35 knots (39 mph) and is located approximately 655 nautical miles west-northwest of Wake Island in the waters of the western North Pacific Ocean. It is centered near 25.2 North and 156.4 East and is moving to the west-northwest at 7 knots (8 mph).

Merbok is expected to track to the northwest and then curve back to the northeast, while remaining over open ocean for the next five days.

Text credit: Rob Gutro, NASA Goddard Space Flight Center, Greenbelt, Md.