Hurricane Isaias forms in the Gulf, northwest of Mexico’s Yucatan Peninsula
Tropical Storm Isaias reached hurricane intensity at 0330 UTC on 08 October 2026 — becoming the first Atlantic Basin (which includes the Gulf of Mexico) hurricane of the 2026 season. 1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Infrared Window images (above) showed the deep convection in the vicinity of the surface storm center of Hurricane Isaias — with GLM Flash Points displaying lightning activity with many areas of deep convection. The coldest cloud-top infrared brightness temperatures associated with convective bursts near the storm center were in the -85 to -90 C range (darker shades of purple).
In an animation of 1-minute GOES-19 Visible images (below), a gradual thinning of high clouds over the storm center eventually revealed an eye for a few hours later in the day.
Isaias continued to intensify to a Category 2 storm by 1800 UTC, in spite of moving through an environment of moderate southwesterly vertical wind shear (below).
A DMSP-18 SSMIS Microwave image (below) depicted a large (but somewhat ragged) eye.
