“How Did Modest Katrina Morph Into Monster?” Based off the Houston Chronicle article by Mark Carreau Object • Examine how the author explains the intensification of Hurricane Katrina as it approached landfall. • Explain the basic science behind the intensification process in a hurricane still over water. • Explore the accuracy of hurricane intensification forecast. Before • • • • Thursday, August 25th Max Sustained Winds: 75mph Max Wind Gusts: 90mph Category: 1 - Katrina spent approximately 7 hours over land before moving into the Gulf of Mexico. After • • • • Sunday, August 28th Max Sustained Winds: 150 kts Minimum Central Pressure: 902mb Category: 5 - Katrina “morphed” in a mere three days, quickly attaining the status of a major hurricane. Causes for intensification as proposed by Mr. Carreau • Lack of a Jet Stream to deflect and sheer the hurricane. • High water temperatures in the Gulf of Mexico. • Bermuda High contributing to low cloud coverage and intense incoming solar radiation. Casey’s Media Accuracy Meter 1. University Level: 2.Knows Their Stuff: == 3. Guess and Check: 4. No Research at All: 5. FOX News: Ocean Temperatures • Provide Fuel for the Hurricane • Higher water temperatures increase the rate of rising air at the core of the storm, helping it organize. Rising air in the core means a lower central pressure, pulling in more air from the surrounding areas and intensifying the storm. • “Two to four degrees may not seem like a lot, but to a hurricane, that is like the difference between running on 89 and 92 octane fuel. That is a significant amount of energy for a storm.” Combined with… Equals: So what’s all this talk about getting high? • Bermuda High prevented any cloud cover from hindering the warming in the Gulf of Mexico on the days prior to the storms entrance. • Also allowed the Gulf Coast waters to rise and transfer their energy into the circulation of the storm. • Bermuda High has expanded this summer until it covered much of the Gulf. Also the reason why your yard is probably brown right about now. So we knew this was going to happen right? ….wwwwweeeelllll, not exactly. Problems with intensification forecast • Too many variables: temperature, winds, moisture, and energy. • All systems are interdependent on each other. • Forecast generally run 5-7 days in advance, meaning change is certain. From the article…. • “Experts know what it takes to fuel such fury, but can’t predict such a storm in advance.” • All data is taken from the NCDC website. Graphs and charts come from the write up summary of Katrina produced by NOAA. • All other images (clip art, monkeys, etc) are public domain.