Nighttime Visible Imagery over the Atlantic
Over the past two weeks, a few hurricanes (Gabrielle, Humberto, and Imelda) traversed over the Atlantic Ocean, and either skirted along or directly impacted the United Kingdom (U.K.) territory of Bermuda. Nighttime visible imagery provided from the VIIRS Near-Constant Contrast (NCC) product captured the synoptic scaled systems across the Atlantic.
Note, for the best optimal viewing of VIIRS NCC, it is recommended to be used during the full moon phase of the lunar cycle (i.e., from ~2 days after the first quarter to ~2 days after the last quarter), since the illumination of features at night is a function of moon phase and elevation above the horizon. However, VIIRS NCC may also be utilized during the new moon phase of the lunar cycle (i.e., moonless nights) to observe atmospheric and surface features, which are predominately illuminated by nightglow. During this period, emitted lights (e.g., city lights) will appear significantly brighter than their surroundings, while atmospheric and surface features (e.g., clouds, snow and ice cover) will appear dim and fuzzy.
VIIRS NCC observes Category 4 – Hurricane Gabrielle at 0549Z, 23 September 2025
At this time stamp, Gabrielle was a Major Hurricane, but stayed east of Bermuda and eventually became a post-tropical cyclone, impacting the Portuguese Azores later that week. While the image is taken during a moonless night, the eye of the hurricane can still be discerned in the imagery. Emitted city lights from Bermuda are seen west of the hurricane as well.
VIIRS NCC observes Category 5 – Hurricane Humberto at 0559Z, 28 September 2025
Humberto experienced peak intensities of 160+ mph winds, where the large cyclone churned through the Atlantic over the course of a week and migrated anticyclonically (clockwise) around Bermuda before dissipating to the north/northeast of the territory. The image below shows the magnitude of Humberto while it was classified as a Category 5 hurricane. The cyclone was located northeast of Puerto Rico and the U.S. and British Virgin Islands. Notice the scattered emitted city lights across the islands.
VIIRS NCC observes Category 1 – Hurricane Imelda at 0632Z, 1 October 2025
Hurricane Imelda and its eye, was located northeast of the Bahamas, and directly east of Florida. Later that day, Imelda intensified into a Category 2 hurricane, before making landfall in Bermuda. Imelda brought heavy precipitation and flooding along with high winds to the remote island. West of Imelda, saturated emitted city lights can be observed along the southeastern U.S., spanning from Florida to the Carolinas.
