Hurricane Ida turned into a monster thanks to a giant warm patch in the Gulf of Mexico – here’s what happened
Subtropical water has a different temperature and salinity than Gulf common water, so its eddies are easy to identify. They have warm water at the surface and temperatures of 78 degrees Fahrenheit (26 C) or more in water layers extending about 400 or 500 feet deep (about 120 to 150 meters). Since the strong salinity difference inhibits mixing and cooling of these layers, the warm eddies retain a considerable amount of heat.
When heat at the ocean surface is over about 78 F (26 C), hurricanes can form and intensify. The eddy that Ida passed over had surface temperatures over 86 F (30 C).
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When warm water extends deep like that, we start to see the atmospheric pressure drop. The moisture transfers, or latent heat, from the ocean to atmosphere are sustained over the warm eddies since the eddies are not significantly cooling. As this release of latent heat continues, the central pressures continue to decrease. Eventually the surface winds will feel the larger horizontal pressure changes across the storm and begin to speed up.
That’s what we saw the day before Hurricane Ida made landfall. The storm was beginning to sense that really warm water in the eddy. As the pressure keeps going down, storms get stronger and more well defined.
When I went to bed at midnight that night, the wind speeds were about 105 miles per hour. When I woke up a few hours later and checked the National Hurricane Center’s update, it was 145 miles per hour, and Ida had become a major hurricane.
Link
Subtropical water has a different temperature and salinity than Gulf common water, so its eddies are easy to identify. They have warm water at the surface and temperatures of 78 degrees Fahrenheit (26 C) or more in water layers extending about 400 or 500 feet deep (about 120 to 150 meters). Since the strong salinity difference inhibits mixing and cooling of these layers, the warm eddies retain a considerable amount of heat.
When heat at the ocean surface is over about 78 F (26 C), hurricanes can form and intensify. The eddy that Ida passed over had surface temperatures over 86 F (30 C).
...
When warm water extends deep like that, we start to see the atmospheric pressure drop. The moisture transfers, or latent heat, from the ocean to atmosphere are sustained over the warm eddies since the eddies are not significantly cooling. As this release of latent heat continues, the central pressures continue to decrease. Eventually the surface winds will feel the larger horizontal pressure changes across the storm and begin to speed up.
That’s what we saw the day before Hurricane Ida made landfall. The storm was beginning to sense that really warm water in the eddy. As the pressure keeps going down, storms get stronger and more well defined.
When I went to bed at midnight that night, the wind speeds were about 105 miles per hour. When I woke up a few hours later and checked the National Hurricane Center’s update, it was 145 miles per hour, and Ida had become a major hurricane.
Link
