image: On Nov. 1, 2012 at 5:29 a.m. EDT the AIRS instrument aboard NASA's Aqua satellite took an infrared picture of Tropical Storm Rosa (left) and System 99E (right). The bulk of Rosa's rainfall was southwest of the storm's center. view more
Credit: NASA JPL, Ed Olsen
Wind shear is pushing the bulk of Tropical Storm Rosa southeast of the storm's center, and that's evident on infrared imagery from NASA's Aqua satellite. Meanwhile System 99E, that was trailing behind Rosa on Oct. 31, has now "given up the ghost" as a result of that same wind shear.
When NASA's Aqua satellite flew over Tropical Storm Rosa at 5:41 a.m. EDT (0951 UTC) on Nov. 1, 2012 the Atmospheric Infrared Sounder (AIRS) instrument took an infrared picture of Tropical Storm Rosa and remnants of System 99E. The AIRS data showed the strongest convection (rising air that forms thunderstorms that make up a tropical cyclone) has been pushed southeast of Rosa's center as a result of northwesterly wind shear. The convection in that quadrant was strong because the air pushed cloud tops of those thunderstorms to the top of the troposphere where temperatures are as cold as or colder than -63 Fahrenheit (-52 Celsius). Those are also areas where heavy rain typically falls. AIRS data showed that Rosa had become more disorganized, and that the banding of thunderstorms around the center was not as well-defined.
At 11 a.m. EDT Nov. 1, the center of Tropical Storm Rosa was located near latitude 13.9 north and longitude 118.4 west, about 825 miles (1,345 km) southwest of Cabo San Lucas, Mexico. Rosa had maximum sustained winds near 50 mph (85 kph) and was moving toward the west-southwest near 2 mph (4 kph). Rosa is expected to drift to the southwest and weaken over the next couple of days.
The low pressure area called System 99E that lies east of Rosa was also affected by wind shear and is no longer suspect for tropical development.