Hurricane Simon Approaches Mexican Coast
Hurricane Simon, part of a series of tropical cyclones in the Eastern Pacific, made its presence felt off the coast of Mexico as a category 4 storm on October 11, 2026. The storm exhibited sustained winds of 250 kilometers (155 miles) per hour while moving north-northwest, with its eye located approximately 50 kilometers (30 miles) from the shore between Manzanillo and Puerto Vallarta.
This information was captured by the VIIRS (Visible Infrared Imaging Radiometer Suite) aboard the Suomi NPP satellite around 2:30 p.m. local time on October 11. At that point, the National Hurricane Center reported that Simon’s sustained winds had decreased to about 210 kilometers (130 miles) per hour, indicating that the storm was nearing the coastline. The Sierra Madre mountains seemed to mitigate the storm’s intensity and reduce the size of its wind field, although Simon still caused significant rainfall and flooding in coastal regions, particularly affecting the port city of Manzanillo.
Atmospheric Impact and Satellite Observations
In the early hours of October 11, meteorological satellites documented the storm’s impact extending into the upper atmosphere. A nighttime image captured by the VIIRS on the NOAA-21 satellite showcased atmospheric gravity waves originating from the hurricane. These waves arise when latent heat released from near the storm’s eyewall stimulates strong convection, leading to the formation of tall cumulonimbus clouds that can produce updrafts capable of sending waves into higher atmospheric layers.
However, these gravity waves are not always detectable, as upper atmospheric winds can dissipate them before they reach the mesosphere, where they become visible as ripples in airglow—subtle light emitted by gases at high altitudes. The day-night band of the VIIRS sensor is adept at picking up airglow, but it can also detect reflected moonlight, which may obscure the phenomena. Fortunately, on the night the image was taken, the limited illumination from the Moon enhanced the visibility of the airglow.
Forecasting Uncertainty Ahead
By the morning of October 13, meteorologists expressed low confidence in forecasting Simon’s path and intensity, as the storm continued to evolve unpredictably. Predictions suggested that Simon could potentially drift northward and enter the Gulf of California before making landfall. In the following days, large swells were expected to create hazardous conditions along parts of Mexico’s southwestern and west-central coasts.
This report includes images from the NASA Earth Observatory, showcasing the storm’s effects as documented by Michala Garrison, utilizing data from various NASA satellite systems. The ongoing situation underscores the challenges of predicting storm behavior in the face of changing atmospheric conditions.
Source: NASA
