NASA sees fading post-Tropical Cyclone John's warmer cloud tops

September 5, 2012
NASA AIRS infrared data on Sept. 4 at 5:23 p.m. EDT showed a circular swirl of clouds in post-tropical storm John where temperatures were around (yellow) 270 kelvin (26.3 F/-3.1 C), which are warm in terms of cloud top temperatures for thunderstorms. Credit: NASA JPL, Ed Olsen

Post-tropical cyclone John has been "flushed" out of existence in the eastern Pacific Ocean, and infrared NASA imagery revealed warmer cloud top temperatures and virtually no precipitation from John's remnants on Sept. 4.

When 's Aqua satellite flew over post-tropical storm John on Sept. 4 at 21:23 UTC (5:23 p.m. EDT) the Atmospheric Infrared Sounder (AIRS) instrument revealed that cloud top temperatures in the storm had warmed over the previous 24 hours. AIRS data also showed there was one very tiny area of (rising air that forms the thunderstorms that make up a tropical cyclone) in the southwestern quadrant of the entire low pressure area. The AIRS showed a circular swirl of clouds where temperatures were around 270 kelvin (26.3 F/-3.1 C), which are warm in terms of cloud top temperatures for thunderstorms. When cloud top temperatures reach the AIRS data threshold of -63F/-52C, they are considered strong thunderstorms.

The last advisory on John was issued by the National Hurricane Center on Sept. 4 at 2100 UTC (5 p.m. EDT), just before the AIRS image was captured by NASA's Aqua satellite. The 5 p.m. advisory put John's center about 505 miles west-northwest of Cabo San Lucas, Mexico, near 24.3 North and 117.7 West. John's were near 35 mph (55 kmh) and weakening. The remnants of John were moving to the northwest at 12 knots (13.8 mph/22.2 kmh) as the low pressure area continued to weaken. John is expected to dissipate later today.

Explore further: Aqua satellite sees weaker Tropical Depression Errol crossing West Timor

Related Stories

Frigid cloud top temperatures show Hurricane Dora's power

July 20, 2011

Extremely cold cloud top temperatures in thunderstorms are an indication of the strength they possess, and infrared satellite data from NASA revealed a large area of very cold and powerful thunderstorms around the center ...

Infrared NASA imagery shows a weaker Tropical Storm 13W

August 7, 2012

Infrared satellite imagery from shows how cold cloud top temperatures are in a tropical cyclone, and recent imagery from NASA's Aqua satellite shows the cloud-top temperatures have been warming in Tropical Storm 13W. Warming ...

NASA sees the short life of Tropical Depression John

September 4, 2012

Tropical Storm John had about one day of fame in the Eastern Pacific. Born Tropical Depression 10, it intensified into Tropical Storm John on Sept. 2 at 5 a.m. EDT and maintained maximum sustained winds of 40 mph (65 kmh) ...

Recommended for you

Asteroid impact, volcanism were one-two punch for dinosaurs

October 1, 2015

Berkeley geologists have uncovered compelling evidence that an asteroid impact on Earth 66 million years ago accelerated the eruptions of volcanoes in India for hundreds of thousands of years, and that together these planet-wide ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.