Satellite captures atmospheric waves above Hurricane Simon off Mexico

A NOAA-21 satellite image taken in the early hours of 11 October shows atmospheric gravity waves spreading from Simon into the upper atmosphere, according to NASA Earth Observatory. The ripples were visible in airglow, the faint light emitted by gases high above Earth, with little moonlight to obscure them. Heat released near a hurricane’s eyewall can drive powerful updrafts that send such waves upwards. [1]

A separate satellite image taken at about 2.30pm local time that day placed Simon’s eye roughly 50 kilometres offshore, between Manzanillo and Puerto Vallarta, according to NASA Earth Observatory. The account describes the hurricane passing close to Mexico’s coast as a category 4 storm on 11 October, with sustained winds reaching 250 kilometres per hour at an unspecified point. By the time of the afternoon image, the National Hurricane Center estimated sustained winds at about 210 kilometres per hour. [1]

News reports cited in NASA’s account described heavy rain and flooding in coastal areas, including Manzanillo, and a risk of mudslides in mountainous areas. By the morning of 13 October, confidence in forecasts of Simon’s path and intensity remained very low, NASA Earth Observatory reported. It said Simon might enter the Gulf of California. [1]