https://phys.org/news/2018-06-infrared-nasa-imagery-hurricane-aletta.html

AIRS saw coldest cloud top temperatures around the center of circulation and in thick feeder bands from the south and east of the storm's center. Those cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

The National Hurricane Center (NHC) noted that Aletta became the first hurricane of the east pacific season on June 7 at 5 p.m. EDT.