NESDIS News Archive

Forecasting a Storm: Understanding Hurricane Intensification

August 25, 2015

Dr. Mark DeMaria, the Technology and Science Branch Chief at the National Hurricane Center, explains the factors contributing to Hurricane Katrina's rapid intensification in 2005.

Deep pools of water 78℉ or more can help a hurricane intensify as it passes over them. Understanding ocean heat content, shown here, can be vital in forecasting a storm's intensification. Credit: NOAA

Hurricane Katrina went from a category 1 to a category 5 hurricane in just 48 hours. This rapid intensification was due to a goldilocks scenario with atmospheric conditions, storm processes, and ocean conditions being “just right”.

Hurricanes need warm water to form and gain strength; scientists use 78℉ or higher as a benchmark temperature. But ocean temperatures can vary dramatically in all directions and depths.

A storm's strength depends not only on the surface temperature, but on the depth of the warm water. Large slow moving storms can churn up deeper, colder water which can actually stall and dissipate a storm, while deep pools of water 78℉ or more can make it much easier for storms to grow stronger.

The measure of this stored heat is known as the ocean heat content (OHC). OHC is an integrated value of the temperature of the ocean from the surface to however deep a specified temperature goes, in this case 78℉.

Credit: NOAA

Scientists derive ocean heat content from the combination of a variety of data, including altimetry data collected by NOAA’s Jason satellites.

The Jason satellites use an altimeter to measure the height of the ocean around the world. From these sea level measurements scientists derive ocean heat content in order to forecast a storm's intensification.

The launch of Jason-3, the most recent in the Jason constellation, will be vital in the continuation and improvement of sea level data collection and in creating more accurate global ocean heat content maps.

Jason-3’s sea level measurements are key to understanding climate change, ocean weather forecasting, and hurricane intensification.

The launch of Jason-3, the most recent in the Jason constellation, will be vital in the continuation and improvement of sea level data collection and in creating more accurate global ocean heat content maps.

Visit the Jason-3 homepage to learn more about Jason-3 and its mission!

Dr. Lynn K. "Nick" Shay and Jodi Brewster on satellite derived ocean heat content and hurricane intensification.