Despite remaining offshore, Hurricane Simon delivered a severe meteorological blow to Mexico’s Pacific coast, unleashing powerful winds, torrential rainfall, and widespread coastal flooding. While emergency management teams and coastal communities scrambled to respond to the immediate terrestrial threats, spaceborne instruments captured an extraordinary and rarely seen phenomenon high above the storm: colossal waves rippling through Earth’s upper atmosphere.

Hurricane Simon represents the latest chapter in an active and formidable season of tropical cyclones sweeping across the Eastern Pacific during the 2026 hurricane season. On October 11, 2026, the Category 4 hurricane tracked dangerously close to Mexico’s rugged coastline while moving in a north-northwestward direction. At the height of its intensity during this phase, the storm sustained ferocious winds reaching up to 250 kilometers (155 miles) per hour, posing a severe threat to maritime traffic, coastal infrastructure, and populated areas alike.

Hurricane Simon Batters Mexico’s Pacific Coast

At approximately 2:30 p.m. local time (20:30 Universal Time) on October 11, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument, operating aboard NASA’s Suomi NPP satellite, obtained a striking high-resolution image of the massive meteorological system. At that precise moment, the eye of Hurricane Simon was positioned roughly 50 kilometers (30 miles) offshore, neatly situated between the major coastal cities of Manzanillo and Puerto Vallarta.

According to updates issued by the National Hurricane Center (NHC), the storm’s maximum sustained winds had eased slightly to approximately 210 kilometers (130 miles) per hour by the time the satellite imagery was acquired. Nevertheless, despite this marginal decrease in wind speed, the hurricane’s formidable inner core remained dangerously close to the shore, continuing to present an acute hazard to coastal municipalities.

Meteorological analysis suggests that the imposing topography of the Sierra Madre mountain range played a crucial mitigating role in limiting Simon’s destructive potential. The rugged, elevated terrain interacted with the circulation of the storm, helping to disrupt its structural organization, reduce its overall intensity, and physically shrink the geographical footprint affected by its strongest gale-force winds.

Even with the moderating influence of the mountains, the hurricane unleashed punishing rainfall and dangerous coastal flooding across numerous communities, including the vital port city of Manzanillo. News reports and local emergency assessments emphasized that the unrelenting downpours significantly heightened the risk of life-threatening mudslides and flash floods in vulnerable, steep terrain throughout the region, prompting local authorities to urge precautionary evacuations.

NASA Captures Strange Waves Above the Hurricane

Even as Hurricane Simon churned menacingly across the surface of the Eastern Pacific, advanced space-based sensors detected a remarkable, invisible disturbance unfolding far above the cloud tops.

During the early morning hours of October 11, the immense thermodynamic energy of the storm generated cascading, rippling disturbances that propagated vertically all the way into Earth’s upper atmosphere. A nighttime satellite observation, captured by the VIIRS instrument aboard the NOAA-21 satellite, successfully documented these atmospheric gravity waves spreading outward in concentric ripples from the center of the hurricane.

These complex atmospheric phenomena are born from intense thermodynamic and convective activity within the storm system itself. Near the churning eyewall of a major hurricane, the massive release of latent heat fuels explosive convection. This process forces vast quantities of warm, moist air to surge violently upward into the troposphere, rapidly constructing towering cumulonimbus cloud formations.

The sheer power of these updrafts acts as a piston against the overlying layers of the atmosphere, disturbing the surrounding air masses and generating internal waves that propagate upward into the stratosphere and mesosphere. Unlike ocean waves, which travel through a liquid medium, atmospheric gravity waves are oscillating disturbances that move through compressible air, with gravity acting as the essential restoring force that drives the wave motion.

Why the Rare Atmospheric Ripples Were Visible

Although intense tropical cyclones frequently generate atmospheric gravity waves during their lifecycles, spaceborne instruments are rarely able to detect and image them directly. High-altitude winds in the upper atmosphere often disrupt, refract, or completely disperse these delicate disturbances long before they can ascend into the mesosphere, where they might otherwise become observable through an atmospheric phenomenon known as airglow.

Airglow is a faint, natural luminescence produced by chemical reactions among gases high in Earth’s upper atmosphere. When atmospheric gravity waves travel upward through this faintly glowing atmospheric layer, they induce subtle, periodic variations in air density and temperature. These fluctuations create visible patterns of alternating brightness and dimness, effectively outlining the distinctive ripple signatures of the waves against the darkness of space.

The day-night band of the VIIRS instrument is uniquely engineered to be sensitive enough to detect this extremely faint natural light emission. However, that same high sensitivity means the sensor also captures scattered moonlight reflected from Earth’s surface and lower atmosphere, which can easily wash out and obscure the much weaker signals of airglow.

Fortunately, environmental and astronomical conditions aligned in an unusually favorable manner at the exact moment the satellite passed over Hurricane Simon. With minimal lunar illumination interfering with the sensor’s field of view, the delicate atmospheric ripples stood out with exceptional clarity, granting researchers an unobstructed look at the striking wave patterns high above the tropical storm.

Hurricane Simon’s Unpredictable Path Raises Concerns

By the morning of October 13, forecasters and meteorologists at meteorological tracking centers found themselves grappling with persistent uncertainty regarding Simon’s future trajectory and intensity.

The National Hurricane Center explicitly characterized its confidence in both the short-term intensity and long-term track forecasts as "very low confidence," underscoring how the storm had repeatedly defied standard meteorological models and behaved in unexpected ways.

Among the various scenarios considered by forecasters was the possibility that Simon could alter its course northward, potentially pushing into the Gulf of California and eventually making landfall along the mainland coast.

Regardless of the storm’s ultimate path and longevity, extensive ocean swells whipped up by the powerful hurricane were projected to generate hazardous surf conditions, dangerous rip currents, and coastal erosion along substantial stretches of Mexico’s southwestern and west-central coastlines over the days following the initial encounter.

NASA Earth Observatory images by Michala Garrison, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, the Suomi National Polar-orbiting Partnership, and the Joint Polar Satellite System (JPSS).