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Hurricane Season 2012: Tropical Depression 5 (North Atlantic Ocean)
8.02.12
 
NASA's Aqua satellite captured a look at Tropical Depression 5's cloud top temperatures on August 2, 2012. › View larger image
NASA's Aqua satellite captured a look at Tropical Depression 5's cloud top temperatures on August 2, 2012 at 12:53 a.m. EDT. Just a small area of coldest cloud top temperatures (purple) were as cold as or colder than -63 Fahrenheit (-52 Celsius), indicating strong thunderstorms with the potential for heavy rainfall. The circulation center is not clear in this image.
Credit: NASA JPL, Ed Olsen
NASA Sees Fifth Atlantic Tropical Depression Form After a Month

NASA infrared satellite imagery provided insight into newborn Tropical Depression Five, that comes over a month after the last Atlantic tropical cyclone. Tropical Storm Debby was the last Atlantic Ocean tropical cyclone to form this season and she met her end on June 28 in the northern Atlantic.

When NASA's Aqua satellite passed over newborn Tropical Depression Five, it captured temperature data from its cloud tops, using the Atmospheric Infrared Sounder (AIRS) instrument that flies onboard. In an image captured on August 2, 2012 at 12:53 a.m. EDT, just a small area of coldest cloud top temperatures were as cold as or colder than -63 Fahrenheit (-52 Celsius), indicating strong thunderstorms with the potential for heavy rainfall. The circulation center, however, was not clear.

On August 2, 2012 at 11 a.m. EDT, Tropical Depression Five's (TD5) maximum sustained winds were near 35 mph (55 kmh). TD5 is located about 450 miles (725 km) east of the Windward Islands, near 13.0 North and 54.3 West and moving west at 20 mph (32 kmh). The low pressure area designated as "System 99L" strengthened into Tropical Depression 5 on August 1, 2012 at 5 p.m. EDT.

A Tropical Storm Watch is in effect for Barbados, St. Vincent and the Grenadines, and Dominica, St. Lucia, Martinique and Guadeloupe.

Forecasters at the National Hurricane Center (NHC) expect "little change in strength likely for the next day or so, but some strengthening is expected thereafter." NHC forecasters expect it to continue moving to the west-northwest and into the Caribbean Sea, while staying south of Puerto Rico. The NHC also expects atmospheric conditions to improve, allowing the depression to become a tropical storm. If TD5 does get a name it would become "Ernesto."

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



Aug. 1, 2012

AIRS captured an infrared image System 99L and showed that there was a small area of strong, high, cold cloud tops of thunderstorms › View larger image
NASA's Aqua satellite passed over System 99L on August 1 at 0405 UTC (12:05 a.m. EDT) and the AIRS instrument captured an infrared image of the storm. It showed that there was a small area of strong, high, cold cloud tops of thunderstorms (purple) around the center of circulation, indicating some strength in the low pressure area.
Credit: NASA JPL, Ed Olsen
NASA Satellite Sees Strength in Developing Atlantic Tropical Low

NASA's Aqua satellite spotted some very cold, high, thunderstorms around the center of a tropical low pressure area in the Atlantic Ocean today, indicating that the system is getting stronger and more organized.

The low pressure area, designated as "System 99L" was located about 850 miles east of the southern Windward Islands, near 10.7 North latitude and 46.9 West longitude. It was moving west between 15 and 20 mph.

NASA's Aqua satellite passed over System 99L on August 1 at 0405 UTC (12:05 a.m. EDT) and the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared image of the storm. It showed that there was a small area of strong, high, cold cloud tops of thunderstorms around the center of circulation, indicating some strength in the low pressure area. Infrared imagery shows temperature and the higher the cloud tops, the colder they are as they reach higher in the troposphere (lowest atmospheric layer). When cloud top temperatures are very cold, it's an indication of strong uplift in the atmosphere. The cloud top temperatures around the center of this low were near -63 Fahrenheit (-52 Celsius), and indicated powerful uplift and high cloud tops.

The National Hurricane Center noted that "environmental conditions are conducive for gradual development," and gives the storm a 70% chance of becoming a tropical depression in the next two days. Residents in the Windward Islands should monitor the progress of System 99L.

If System 99L develops into a tropical storm, it would be named "Ernesto." The last tropical storm to form in the Atlantic Ocean this hurricane season was Debby, and she dissipated over a month ago, on June 28.

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