Hurricane Simon Lurks Off the Mexican Coast

Earth Observatory Science Earth Observatory Hurricane Simon Lurks Off the… Earth Earth Observatory Image of the Day EO Explorer Topics All Topics Atmosphere Land Heat & Radiation Life on Earth Human Dimensions Natural Events Oceans Remote Sensing Technology Snow & Ice Water More Content Collections Global Maps World of Change Articles Earth Matters Blog Blue Marble: Next Generation EO Kids Mission: Biomes About About Us Subscribe 🛜 RSS Contact Us Search Hurricane Simon churns off Mexico’s Pacific coast in this image acquired with the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite on October 11, 2026. NASA Earth Observatory/Michala Garrison Hurricane Simon, the latest in a long progression of tropical cyclones in the Eastern Pacific this season, passed close to the Mexican coast as a category 4 storm on October 11, 2026. Sustained winds reached 250 kilometers (155 miles) per hour as it crept north-northwest. Simon’s eye was about 50 kilometers (30 miles) offshore, between Manzanillo and Puerto Vallarta, when the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite acquired this image around 2:30 p.m. local time (20:30 Universal Time) on October 11. By that time, sustained winds were about 210 kilometers (130 miles) per hour, according to the National Hurricane Center (NHC), and the storm’s inner core was brushing up against the coast. The topography of the Sierra Madre mountains appeared to temper the storm’s intensity somewhat and shrink the size of its wind field, the NHC noted. Still, the major hurricane delivered heavy rain and flooding to coastal areas, including the port city of Manzanillo, and raised the risk of mudslides in mountainous areas, according to news reports . Atmospheric gravity waves generated by Hurricane Simon are visible via mesospheric airglow in this nighttime image acquired with the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-21 satellite on October 11, 2026. NASA Earth Observatory/Michala Garrison In the early morning hours of October 11, satellites captured the storm’s effects extending into the upper atmosphere . This nighttime image (above), acquired with VIIRS on the NOAA-21 satellite, shows atmospheric gravity waves radiating from the hurricane. 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. But these waves are not always observable. Winds in the upper atmosphere can dissipate them before they reach the mesosphere, where they show up as ripples in airglow—faint light emitted by gases at those high altitudes. The VIIRS day-night band is sensitive to airglow but also detects reflected moonlight, which can wash it out. On the night this image was acquired, minimal illumination from the Moon helped the airglow stand out. On the morning of October 13, forecasts of Simon’s intensity and path remained “very low confidence,” as the storm’s evolution continued to defy meteorologists’ expectations . The system may steer north and enter the Gulf of California before making landfall. Large swells causing dangerous nearshore conditions were expected along portions of the southwestern and west-central coasts of Mexico in the coming days. 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). Story by Lindsey Doermann. Downloads October 11, 2026: Suomi NPP JPEG (3.05 MB) October 11, 2026: NOAA-21 JPEG (1.86 MB) References & Resources Hoffmann, L., et al. (2018) Satellite observations of stratospheric gravity waves associated with the intensification of tropical cyclones . Geophysical Research Letters , 45, 1692–1700. NASA (2018, October 22) Why NASA Watches Airglow, the Colors of the (Upper Atmospheric) Wind . Accessed October 13, 2026. NASA Earth Observatory (2026, June 1) Gravity Waves From Super Typhoon Sinlaku . Accessed October 13, 2026. National Hurricane Center (2026, October 13) Hurricane SIMON Advisory Archive . Accessed October 13, 2026. Reuters (2026, October 12) Hurricane Simon crawls along Mexico’s Pacific coast, bringing floods and evacuations . Accessed October 13, 2026. You may also be interested in: Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet. Powerful Storms Continue to Prowl the Pacific 4 min read Hurricanes Polo and Nolo sent destructive effects ashore amid an active season in the northeastern and central Pacific. 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