GPM observes Hurricane Dorian lashing Florida

GPM captured Dorian at 10:41 UTC (6:41 am EDT) on the 4th of September when the storm was moving north-northwest parallel to the coast of Florida about 90 miles due east of Daytona Beach. Three days earlier, Dorian had struck the northern Bahamas as one of the most powerful Category 5 hurricanes on record in the Atlantic with sustained winds of 185 mph. Weakening steering currents allowed the powerful storm to ravage the northern Bahamas for 2 full days. During this time, Dorian began to weaken due to its interactions with the islands as well as the upwelling of cooler ocean waters from having remained in the same location for so long. Immediately apparent is Dorian’s well-defined but very large eye. This feature is often seen in the later stages of powerful tropical cyclones, which includes hurricanes and typhoons. As these mature, powerful storms age, their wind field tends to expand. They often undergo what is known as eye wall replacement cycles wherein a 2nd concentric eye wall forms outside of the original inner eye wall. The inner eye wall is choked off and weakens leaving the outer eye wall as the dominant eye wall. The outer eye wall can still contract, but often the storm is left with a larger eye as is the case with Dorian. At the time of this image, Dorian’s maximum sustained winds were still 105 mph, making it a Category 2 storm, but a very large Category 2 storm.

GPM data is archived at https://pps.gsfc.nasa.gov/