NASA infrared data shows storm Cristina strengthening

NASA's Aqua satellite revealed better organization and colder cloud top temperatures in tropical storm Cristina on Friday, indications that the storm was strengthening.

The satellite analyzed tropical storm Cristina's cloud tops in infrared light, and found that the most powerful thunderstorms were east and south of the center of circulation, where temperatures were as cold as or colder than minus 56.6 Celsius, according to NASA.

These cloud top temperatures had become colder than they were over the previous day. Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall, said NASA.

"Cristina has become better organized during the past several hours. A curved band wraps almost completely around the center, and a ragged eye has occasionally been apparent in satellite images," said a release of the U.S. National Hurricane Center.