Tropical storm MA-ON (08W), that developed east of the Marianas in the northern Pacific Ocean yesterday, has continued to become more powerful. MA-ON had wind speeds of about 35 kts (~40 mph) when the TRMM satellite saw the storm on 12 July 2011 at 0640 UTC and is predicted to gradually strengthen over the next five days. MA-ON is then expected to be a powerful typhoon with wind speeds of 95 kts (~109 mph) and be located in the open waters of the Pacific Ocean south of Japan.

TRMM Microwave Imager (TMI) and Precipitation Radar (PR) data were used in the rainfall analysis being drawn on the Visible/Infrared (VIRS) image shown above. TMI data show that MA-ON had heavy rainfall around the storms center of circulation and also in a large feeder band converging into the the eastern side of the storm.