NASA infrared imagery indicates Pewa weakened

Aug 23, 2013
This infrared image from NASA's Aqua satellite on Aug. 22 at 01:35 UTC showed a limited area of cloud top temperatures of thunderstorms east of the center of Tropical Storm Pewa were cold as -63F/-52C (purple) indicating strong storms. Credit: NASA/JPL

Cloud top temperatures warmed up on NASA infrared imagery, indicating that the uplift in Tropical Storm Pewa was waning. By Aug. 23, Pewa was reduced to a tropical depression. Infrared imagery also showed that wind shear has pushed Pewa's precipitation away from the storm's center.

On Aug. 22 at 01:35 UTC (2:53 p.m. EDT) NASA's Atmospheric Infrared Sounder or AIRS instrument that flies aboard NASA's Aqua satellite showed a limited area of cloud top temperatures in bands of thunderstorms east of the center of Tropical Depression Pewa were as cold as -63F/-52C, indicating strong storms. Satellite data indicated that Pewa's low-level circulation center is partially exposed to outside winds and wind shear continues to push the bulk of precipitation east of the center.

AIRS are false-colored to show temperature differences. Scientists look at cloud top temperatures to understand how high the thunderstorms are that make up a tropical cyclone - and there are hundreds of thunderstorms that make up one storm. The colder the cloud top temperature, the higher the top of the thunderstorm reaches into the troposphere and the stronger the storm. NASA research has indicated that cloud top temperatures that reach or exceed the threshold of -63F/-52C typically have heavy rainfall rates.

On Aug. 23 at 1500 UTC/11 a.m. EDT Tropical Depression Pewa's had fallen to 30 knots/34.5 mph/55.5 kph. Pewa was centered near 26.9 north and 168.5 east, about 458 nautical miles northeast of Wake Island. Pewa is moving to the northeast at 4 knots/4.6 mph/7.4 kph. Forecasters at the Joint Typhoon Warning Center expect Pewa to turn back to the northwest and continue on a northerly track over open ocean.

The Joint Typhoon Warning Center noted that Pewa is expected to struggle over the next several days is it moves in a northerly direction. Pewa is also expected to become extra-tropical over the next couple of days.

Explore further: NASA sees Tropical Storm Pewa temporarily weaken

add to favorites email to friend print save as pdf

Related Stories

NASA sees Tropical Storm Pewa temporarily weaken

Aug 20, 2013

Tropical Storm Pewa weakened temporarily while facing adverse atmospheric conditions in the Northwestern Pacific, and NASA's Aqua satellite captured the storm in infrared light.

NASA satellite sees Pewa become a typhoon

Aug 19, 2013

NASA's Aqua satellite passed over the tropical cyclone known as Pewa after it strengthened into a typhoon in the northwestern Pacific Ocean. The Aqua satellite image revealed that Pewa had developed a small ...

Recommended for you

Clean air: Fewer sources for self-cleaning

4 hours ago

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

4 hours ago

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Image: Grand Canyon geology lessons on view

11 hours ago

The Grand Canyon in northern Arizona is a favorite for astronauts shooting photos from the International Space Station, as well as one of the best-known tourist attractions in the world. The steep walls of ...

First radar vision for Copernicus

11 hours ago

Launched on 3 April, ESA's Sentinel-1A satellite has already delivered its first radar images of Earth. They offer a tantalising glimpse of the kind of operational imagery that this new mission will provide ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Researchers discover target for treating dengue fever

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...