NASA's MODIS instrument on the Terra satellite captured Cyclone Anja in the southern Indian Ocean on November 16 at 1 a.m. ET (0600 UTC). Credit: NASA, MODIS Rapid ResponseOvernight Cyclone Anja continued on its power trip. Yesterday, November 16, Anja was a Category 3 Cyclone. Today, Anja has reached Category 4 status on the Saffir-Simpson scale as the storm's maximum sustained winds have increased to 115 knots (132 mph). NASA's Aqua satellite makes daily overpasses from space and has observed the towering thunderstorms as the cloud top temperatures have grown colder. The latest satellite imagery from the Atmospheric Infrared Sounder (AIRS) instrument on Aqua taken at 0930 UTC (4:30 a.m. ET), revealed that cloud top temperatures were colder than minus 63 degrees Fahrenheit! That puts cloud tops near the top of the troposphere, meaning the cyclone has some very powerful thunderstorms in it.
AIRS data is also coupled with data from the Advanced Microwave Sounding Unit (AMSU) that flies with AIRS on Aqua to create microwave images of storms. The AMSU image uses the radiances of the 89 GHz channel, and it revealed cold areas that indicated precipitation or ice in the cloud tops.
At 10 p.m. ET on November 16 (0300 UTC November 17), Anja was located about 715 miles east-northeast of La Reunion Island, near 16.4S and 67.3E. Reunion Island is located east of Madagascar in the Indian Ocean. The nearest island is Mauritius which is 120 miles to the northwest. Anja was moving toward the south-southwest near 13 mph.
Anja is a compact storm, with hurricane-force winds extending only 25 miles from the centre, and tropical storm-force winds extending only 75 miles from the centre.
Anja is forecast to move southeast and weaken in the next day or two.
Author: Rob Gutro, NASA/Goddard Space Flight Centre
