Warmer Ocean Fuels Hurricane Dean

A new NASA animation shows the rise in sea surface temperatures that helped to spawn Hurricane Dean in the central Atlantic and Tropical Storm Erin in the Gulf of Mexico this week.

Sea surface temperatures are a key ingredient for hurricane and tropical storm formation and they were warming up in the Gulf of Mexico, Caribbean and eastern Atlantic Ocean by the middle of August.

By late June, sea surface temperatures in the Gulf of Mexico were all more than 80 degrees Fahrenheit. Hurricane forecasters watch for that figure: It's the threshold needed to power tropical depressions into tropical storms and grow them into hurricanes.

These areas of warm sea surface waters (80 degrees Fahrenheit or higher) are depicted in yellow, orange and red in the NASA animation.

This data was taken by the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) instrument aboard the Aqua satellite.

The animation shows the progression of warm waters slowly filling the Gulf of Mexico (shown in yellow, orange and red). This natural annual warming contributes to the possible formation of hurricanes in the Gulf. Sea surface temperature data shown here ranges from Jan. 1, 2007 to the present.

"The many Atlantic and Gulf citizens still reeling from the shock of the 2004 and 2005 Atlantic hurricane seasons, received some good news … the Atlantic sea surface temperatures that fuel hurricanes are somewhat cooler than the past few years," said Bill Patzert, oceanographer at NASA's Jet Propulsion Laboratory in California. "Based on this, some forecasters have reduced their forecasts. But the news is mixed."

Hurricane and tropical storm forecasters are watching additional factors, Patzert said.

"The jet stream has remained stubbornly north, the possibility of a late-developing La Nina is lurking and Gulf of Mexico and Caribbean sea surface temperatures are ripe for late-season hurricane development," he said.

Gulf and Atlantic coast residents should definitely be prepared for storm and hurricane activity, in any case.

Hurricane season started on June 1 and ends on Nov. 30.

• NASA Animation of Warming Sea Surface Temperatures
• Images: Hurricanes From Above
• Hurricane Dean Updates
• 2007 Hurricane Guide