NASA has released a nighttime satellite image showing Hurricane Simon pushing rings of atmospheric ripples high above Mexico's Pacific coast, far above the clouds that were drenching Manzanillo and Puerto Vallarta. The image, captured early Oct. 11 by the VIIRS instrument on the NOAA-21 satellite and published by NASA Earth Observatory, shows atmospheric gravity waves spreading outward from the storm and lighting up as faint bands in airglow.

The storm that produced them is now gone. The National Hurricane Center issued its final advisory at 2 p.m. MST on Oct. 16, saying Simon had dissipated about 100 miles (160 kilometers) south-southwest of Cabo San Lucas with no coastal watches or warnings in effect.

For people who live on, or travel to, Mexico's Pacific coast, the image is a reminder that a hurricane's reach is not only sideways but upward. It does not add any ground-level risk, but it helps scientists study how powerful storms move energy into layers of the atmosphere that weather forecasts rarely consider.

Update Note: This article reports new information involving Hurricane Simon's upper-atmosphere effects and final status following Nature World News' earlier coverage. The latest verified information comes from the National Hurricane Center's final advisory on Simon, issued Oct. 16, 2026, at 2 p.m. MST, and NASA Earth Observatory's Oct. 14 image release, last updated Oct. 15 at 8:33 a.m. EDT.

Storm Updrafts That Reached the Mesosphere

The ripples began deep inside the hurricane. Near the eyewall, heat released as water vapor condenses powers strong rising air, building towering cumulonimbus clouds. Those updrafts can disturb the stable air above them and launch waves that travel up through the stratosphere and into the mesosphere, the layer of the atmosphere that extends roughly 31 to 53 miles (50 to 85 kilometers) above the ground.

These are atmospheric gravity waves, not the gravitational waves astronomers detect from colliding black holes. Gravity acts as the restoring force, much as it pulls a bobbing buoy back toward the water's surface.

Seeing them takes luck — strong winds high in the atmosphere often break the waves apart before they reach the mesosphere. When they survive, they ripple through airglow, a faint natural light given off by gases at those altitudes. The VIIRS day-night band can detect that glow, but moonlight usually drowns it out. NASA said very little moonlight on Oct. 11 allowed the ripples to stand out.

Coastal Damage While the Eye Stayed Offshore

Simon passed close to the coast as a Category 4 hurricane on Oct. 11, with sustained winds reaching 155 mph (250 km/h), according to NASA. By about 2:30 p.m. local time that day, its winds had eased to about 130 mph (210 km/h), and its eye sat roughly 30 miles (50 kilometers) offshore between Manzanillo and Puerto Vallarta. NASA said the Sierra Madre mountains appeared to weaken the storm and shrink its wind field, but heavy rain still flooded coastal areas and raised the risk of mudslides.

Nature World News previously reported on Simon's weakening to Category 3 off Puerto Vallarta as a hurricane watch extended north toward Sinaloa. In the days that followed, the storm stalled and drifted. In its Oct. 13 discussion, the hurricane center wrote that "Small stubborn Simon continues to defy expectations this morning," and called its track and intensity forecast very low confidence.

The human toll was shared with another storm. CBS News reported on Oct. 13 that Simon and former Tropical Storm Rachel together had killed six people in Mexico, with flooding in Baja California, largely tied to Rachel, accounting for much of the damage and the missing. Those figures were preliminary and may change.

Helene, Sinlaku and a Pattern Satellites Keep Catching

Simon is not the first storm caught in the act — in September 2024, NASA's Atmospheric Waves Experiment recorded gravity waves from Hurricane Helene as the storm struck Florida's Gulf Coast. Earlier this year, NASA Earth Observatory documented similar waves from Super Typhoon Sinlaku in the western Pacific.

These observations matter because energy carried upward by such waves helps shape conditions in the upper atmosphere, a region linked to the ionosphere that affects some radio and satellite signals. Storms are one of many sources, along with mountains, jet streams and weather fronts.

The evidence here should be read carefully. The Simon image is an observation, not a new study, and it does not measure how much energy the storm sent upward. Research cited by NASA, including a 2018 study in Geophysical Research Letters, has linked stratospheric gravity waves to tropical cyclones that are intensifying. Upper-atmosphere imagery is not used by the hurricane center to issue warnings, and it does not change the public safety guidance for a storm.

Swells, Saturated Hillsides and a Season Still Running

The final advisory noted that swells from Simon's remnants could still affect parts of west-central Mexico and Baja California Sur. Travelers heading to Puerto Vallarta, Manzanillo or Los Cabos should check local beach flags and follow lifeguard instructions, since swells can produce dangerous rip currents even on sunny days far from a storm.

Inland, the greater risk is the ground itself. Rain on already saturated hillsides can trigger mudslides faster, and communities still cleaning up may have blocked drainage and damaged roads. Residents should follow Mexico's civil protection authorities and national weather service for local warnings.

The eastern Pacific hurricane season runs through Nov. 30, and the 2026 season has been unusually active. Travelers with trips planned to Mexico's Pacific coast should monitor the hurricane center's outlooks in the days before departure and review their travel insurance terms.

The bottom line is that Simon ended over open water on Oct. 16, but not before a satellite captured it rippling the atmosphere dozens of miles overhead. The image adds to a growing record of storms reaching the edge of space, while the practical concerns on the ground remain swells, mudslides and recovery along a coast that saw several storms this month.

What Readers Want to Know

What did the NASA image show?

It showed atmospheric gravity waves spreading outward from Hurricane Simon early on Oct. 11, visible as ripples in faint airglow high above Mexico's Pacific coast.

Are atmospheric gravity waves dangerous?

No. They occur far above the ground and pose no direct hazard to people. They are studied for what they reveal about the upper atmosphere.

Why were the ripples visible this time?

Upper-level winds did not break the waves apart before they reached the mesosphere, and very little moonlight let the faint airglow stand out.

Is Hurricane Simon still active?

No. The National Hurricane Center said Simon dissipated on Oct. 16, and no coastal watches or warnings were in effect in its final advisory.

Which areas were hit hardest?

Coastal Colima and Jalisco saw flooding and mudslide risk from Simon, while deadly flooding in Baja California was largely linked to Rachel.

What should travelers to Mexico's Pacific coast watch for now?

Lingering swells and rip currents, plus mudslide risk inland. Follow local beach flags and Mexican civil protection guidance.