On 11 October 2026 the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured a striking image of Hurricane Simon churning off Mexico’s Pacific coast. The storm had already reached category 4 intensity, with sustained winds of 250 kilometers (155 miles) per hour as it crept north‑northwest. Simon’s eye sat about 50 kilometers (30 miles) offshore, between the port city of Manzanillo and Puerto Vallarta, when the satellite snapped the picture around 2:30 p.m. local time (20:30 Universal Time).

Satellite remote sensing of a tropical cyclone

VIIRS measures visible and infrared radiation, allowing scientists to estimate wind speed, track the storm’s core, and monitor how land interaction modulates intensity. The Sierra Madre mountains bordering the coast acted as a partial barrier, temporarily weakening the hurricane and shrinking its wind field, as noted by the National Hurricane Center. Such observations illustrate how satellite data complement surface reports and help forecasters assess rapid intensification or decay.

Atmospheric gravity waves visible in the upper atmosphere

Later that day, the NOAA‑21 satellite recorded a nighttime VIIRS image in which atmospheric gravity waves radiate from the hurricane’s eyewall. These ripples form when latent heat released near the tropical cyclone’s eyewall drives strong convection, building tall cumulonimbus clouds with updrafts that can send waves into the stratosphere and mesosphere. On the night the image was acquired, minimal moonlight allowed the faint airglow—emission from gases at high altitudes—to stand out, making the waves observable. In other cases, upper‑level winds can dissipate the waves before they reach the mesosphere, so visibility depends on a delicate balance of convection, background winds, and lunar illumination.

Forecast uncertainty and real‑world impacts

By the morning of 13 October, the National Hurricane Center described Simon’s intensity and path forecast as “very low confidence,” reflecting the storm’s continued defiance of model expectations. The system could turn north and enter the Gulf of California before making landfall, while large swells and dangerous nearshore conditions were already expected along portions of southwestern and west‑central Mexico. Heavy rain and flooding affected coastal areas, and the risk of mudslides increased in mountainous terrain.

Educational take‑aways for students and educators

  • Satellite instruments such as VIIRS provide near‑real‑time data on wind speed, precipitation, and cloud structure, forming a cornerstone of modern meteorology.
  • Gravity‑wave dynamics link surface weather to upper‑atmosphere processes, illustrating how energy propagates from the troposphere to the mesosphere.
  • Forecast confidence can shift rapidly; monitoring multiple data streams (satellite, radar, surface stations) is essential for reliable predictions.

Project ideas vs. tested implementations

Tested implementation: Educators can use NASA’s Global Imagery Browse Services (GIBS) to pull VIIRS images of recent tropical cyclones, overlay them with wind‑speed estimates, and explore how eye size changes with land interaction. The service is freely accessible and requires only a web browser.

Project idea: Students can write a short Python script that downloads a VIIRS image from GIBS, extracts pixel‑level brightness values, and plots a simple cross‑section of cloud top temperature. Because GIBS provides JSON‑linked metadata, learners can also experiment with time‑series animations of a storm’s evolution. This exercise reinforces concepts of remote‑sensing data handling without requiring specialized software or paid subscriptions.

Source

NASA Science