After a relatively quite period, the Atlantic hurricane season is beginning to heat up with two active storms. This image shows Tropical Storm Dean as it moves westward through the central Atlantic in the general direction of the Lesser Antilles. The image was taken by the Tropical Rainfall Measuring Mission (or TRMM) satellite at 13:20 UTC (9:20 am EDT) on the 15th of August 2007 and shows the horizontal pattern of rain intensity within Dean. Rain rates in the center of the swath are from the TRMM PR, and those in the outer swath come from the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). Although Dean is still a relatively small storm, it appears to be fairly well-organized. TRMM detects an eye in the rain field that is not visible in the IR image (white center in the middle of the upper-right-most rain area). There is also good curvature evident in the rain bands surrounding the center (green arcs indicating moderate intensity rain), which is a further indication that Dean already has a well-formed circulation. At the time of this image, Dean was still a tropical storm with sustained winds estimated at 50 knots (58 mph) by the National Hurricane Center. Dean is forecast to intensify and could become not only the first hurricane but also the first major hurricane of the season.
Click to See a " 3-D FLYBY " animation made from TRMM Precipitation Radar data.

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Images and animations produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC)