An instrument on NASA’s Aqua satellite noticed increasing colder cloud top temperatures of tropical depression 15 in the south-central Caribbean just before it strengthened into Tropical Storm Matthew late on Sept. 23. The TRMM satellite also spotted heavy rainfall within the system. Matthew is now headed to the western Caribbean and watches and warnings are in place as Matthew may continue to strengthen. Cloud top temperatures indicate the strength of the storm to forecasters. The colder the cloud top temperatures, the stronger the convection and uplift. When cloud top temperatures drop, as they did in Atmospheric Infrared Sounder (AIRS) imagery captured on Sept. 23 at18:53 UTC (2:53 p.m. EDT) it indicates the storm is gaining strength. At that time, Matthew’s maximum sustained winds were near 40 mph. In the image, the coldest cloud top temperatures (colder than -63 Fahrenheit) appeared around the center of Matthew’s circulation already giving the appearance of an eye. The AIRS infrared image on Sept. 24 at 3:05 a.m. EDT showed a concentrated area of strong thunderstorms around Matthew’s center as the sustained winds had increased to 50 mph.
NASA satellites see Tropical Storm Matthew grow quickly, warnings up in Central America
September 25, 2010