1. A NASA weather and climate model now (2015) has a resolution of 4 miles, and updates the dynamic state of the atmosphere every 5 seconds and physical processes every 5 minutes.
2. Katrina's wind speed is shown on the left, water vapor on the right.
3. Abundant water vapor was one factor that helped to intensify Katrina to a Category 5 storm, with sustained wind speeds of 175 mph.
4. But, 18 hours later Katrina made landfall over Louisiana as a Category 3 storm, with winds of 125 mph.
TAG: Detailed computer models will help meteorologists understand these quick wind changes and make better forecasts about hurricane strength at landfall.