Hurricane Ida tracked into the Gulf of Mexico Friday night with sea surface temperatures 1-2 degrees above normal.
The National Oceanic and Atmospheric Administration gathers sea surface temperatures with equipment on ships and satellite data.
Hurricanes need ocean temperatures to be 80 degrees 165 feet deep. The sea surface temperatures in the gulf were running around 84 degrees on Friday. The area along the coast of Louisana was closer to 88 degrees.
Warm ocean water is the key ingredient needed to fuel tropical storms. Rapid intensification occurred as the hurricane approached the warm water off the coast of Louisiana. The wind speed increased 35 mph within a 24 hour period due to the warm ocean water, and low vertical wind shear.
One sign of rapid intensification is nearly uniform precipitation around the eyewall.
The warm ocean water near the Louisiana coast was able to continue to fuel the system well onshore. Hurricane-force winds were observed around 130 miles inland before the National Hurricane Center downgraded the system to a tropical storm with 60 mph winds.
Category 4 Hurricanes are rare. Since 1965 Louisiana has been impacted by nine Category 4 Hurricanes and one Category 5 storm.
Only 6 made a direct landfall at Category 4 strength on the state. All of these storms continued producing hurricane-strength winds at least 130 miles inland. Last year Laura produced 100 mph winds in Ruston, Louisiana nearly 200 miles off the coast.
Hurricanes need warm ocean water to survive. They don’t last too long without the ocean, but the hot and humid conditions across the SE can help keep these systems organized until wind shear on the land and the lack of necessary moisture eventually weakens the storm.