Monday, June 25, 2012

NASA sees first Atlantic hurricane fizzling in cool waters

Rob Gutro at NASA: Chris may have been the Atlantic Ocean Hurricane Season's first hurricane, but didn't maintain that title for long. NASA satellite data revealed one good reason why Chris had weakened and became a post-tropical storm.

Sea surface temperatures play a big role in keeping a tropical cyclone alive. They need warm seas of at least 300 Kelvin (80 Fahrenheit/26.8 Celsius) to maintain strength. NASA's Aqua satellite revealed that those conditions were not met where Chris is located in the Atlantic Ocean.

When NASA's Aqua satellite passed over Chris at 0447 UTC (12:47 a.m. EDT) today, June 22, the Atmospheric Infrared Sounder (AIRS) instrument captured a new infrared image of Chris' clouds and surrounding sea surface temperatures. The sea surface temperatures to the south of Chris are at least 300 Kelvin (80 Fahrenheit/26.8 Celsius) and warmer. In the area where Chris is located, AIRS revealed that sea surface temperatures are closer to 290 Kelvin (62 Fahrenheit/16.8 Celsius).

At 11 a.m. EDT on June 22, Chris was now classified as a post-tropical storm with maximum sustained winds near 45 mph (75 kmh). Chris was far to the north near 44.6 North and 46.9 West, about 335 miles (535 km) east-southeast of Cape Race, Newfoundland, Canada. Chris was moving to the west-southwest near 16 mph (kmh), and is expected to slow and turn southward. Chris' minimum central pressure is 990 millibars.

According to the National Hurricane Center, Chris "should merge with another extratropical low on Saturday [June 23]" in the north Atlantic Ocean...

NASA's Aqua satellite passed over Chris on June 22 at 12:47 a.m. EDT and infrared data from the AIRS instrument inidicated the storm is in waters too cool to maintain strength. The waters are near 290 Kelvin (62F/16.8C). Credit: NASA/JPL, Ed Olsen

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