Posted by jack ruby on 4/17/2009, 6:57 pm, in reply to "3D View"

JAC, do the towers themselves rotate within the overall vortex? Seems like I remember seeing sat pics of tiny (relative) vortices (or cloud formations) rotating very near the eyewall. Were these the tops of towers? Or am I just way off base? --Previous Message-- : : : : : Tropical cyclones can extend hundreds of : miles from one side to another, and the : human eye can't possibly see an entire : storm, but a NASA satellite can. NASA's : Tropical Rainfall Measuring Mission (TRMM) : not only sees the storm, but the rainfall : inside of it, and scientists can visualize : storms, including clouds and rainfall in : 3-D. : : That's what NASA scientists have done with : Cyclone Bijli located in the Bay of Bengal. : The 3-D TRMM Precipitation Radar instrument : helped create a 3-D image of Bijli on April : 16. It shows a well organized storm with : intense thunderstorms reaching above 15 : kilometers (9.3 miles) high in the western : edge of a partially closed eyewall. Those : high clouds known as "hot towers" : are indicative of a strengthening storm. : Bijli is expected to make landfall as a : tropical storm over the weekend. : : : : TRMM acts like a "rain gauge in : space" and can estimate rainfall in : storms. On April 16, TRMM flew over Bijli : and captured this image of rainfall : happening throughout the storm. The TRMM : rainfall analysis shows bands of intense : rainfall in the western side of Tropical : Cyclone Bijli. The storm's center is located : near the yellow, green and red areas, which : indicate rainfall between 20 and 40 : millimeters (.78 to 1.57 inches) per hour. : The red areas are considered moderate : rainfall. : : On Friday, April 17, Cyclone Bijli was : raining on northeastern coastal India and : Bangladesh, and headed toward a landfall in : southern Bangladesh. At 0900 UTC (5 a.m. : EDT) on April 17, Bijli's center was about : 130 miles south-southwest of Kolkata, India. : That's near 20.4 degrees north latitude and : 89.0 degrees east longitude. The storm was : moving east-northeast near 12 knots (13 : mph), and packing sustained winds near 50 : knots (57 mph). : : Bijli is forecast to intensify slowly as it : heads east. The Joint Typhoon Warning : Center, the organization that forecasts : cyclones in that area of the world, : forecasts that Bijli will attain 60 knots : (69 mph) just before landfall. That means it : isn't expected to attain hurricane strength, : and will likely make landfall as a strong : tropical storm. Landfall is expected near or : south of Chittagong, Bangladesh sometime on : April 18. : : : : The Atmospheric Infrared Sounder (AIRS) : instrument on NASA's Aqua satellite captured : an infrared image of Bijli on Apr. 17 at : 6:59 UTC (2:59 a.m. EDT). : : The infrared image shows Bijli's cold clouds : in purple and blue. Those temperatures are : as cold as or colder than 220 degrees Kelvin : or minus 63 degrees Fahrenheit (F). The blue : areas are around 240 degrees Kelvin, or : minus 27F. The colder the clouds are, the : higher they are, and the more powerful the : thunderstorms are that make up the cyclone. : In the area false colored as purple, that's : where meteorologists would also find the : "hot tower" clouds that the TRMM : satellite sees. : : At the time of this image, Cyclone Bijli's : northeastern clouds and rains had already : extended into Bangladesh. : : Bangladesh and Burma (Myanmar) can expect : their coasts to be battered with high waves : and gusty winds to tropical storm strength : from now through Bijli's landfall. Tropical : storm-force winds extend out to 65 miles : from the center. Bijli is expected to make : landfall on April 12 in southern Bangladesh, : south of the city of Chittagong. : : Text credit: Rob Gutro, NASA's Goddard Space : Flight Center : : : : :