Typhoon Songda was east of the Philippines when the Tropical Rainfall Measuring Mission (TRMM) satellite had an early evening view on May 25, 2011 at 0903 UTC (05:03 EDT) and saw good organization within the storm and heavy rainfall. Songda has intensified into a major typhoon as it tracks parallel to the east coast of the northern Philippines, spawning warnings.

Both TRMM’s Microwave Imager (TMI) and Precipitation Radar (PR) instruments were used to provide the rainfall analysis. TRMM’s TMI had the best coverage of rainfall with Songda and showed well organized bands of moderate to heavy rainfall converging into the typhoon. TRMM is managed by both NASA and the Japanese Space Agency, JAXA.

Infrared imagery from the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite showed an eye about 12 nautical miles wide and strong convection surrounding the eye on all sides. Songda intensified over the over the last 12 hours because of very warm sea surface temperatures between 30 and 31 Celsius, and low wind shear.

At 1500 UTC (11 a.m. EDT) on May 25, Songda’s maximum sustained winds were near 105 knots (120 mph/194 kmh) making it a Category Three Typhoon on the Saffir-Simpson scale. Sondga was located about 385 nautical miles east-southeast of Manila, Philippines and is now moving northwestward near 5 knots (6 mph/9 kmh). Yesterday it was moving to the west-northwest, so the curving northward has already begun.

Songda is predicted to become a very powerful category 4 super typhoon with wind speeds peaking at 125 knots (143 mph/231 kmh) as it passes to the northeast of the Philippines. By Friday, the current forecast track takes Songda’s center very close to the island with Kadena Air Base in the Northwestern Pacific Ocean.

NASA satellites are all keeping an eye on for possible development. They are Systems 90S, 91S and 99S in the Southern Pacific, and System 93B in the Northern Indian Ocean. Despite a poor chance for development in all of them, one has triggered warnings in northern Australia because of its proximity to land. NASA and the Japanese Space Agency manage the Tropical Rainfall Measuring Mission or TRMM satellite and TRMM passed over two of those four systems today. TRMM captured light to moderate rainfall in the low pressure area called “System 90S” on March 30 at 01:49 UTC. Rainfall rates were between 5 and 20 millimeters (0.2 and 0.8 inches) per hour within the storm. System 90S is located 500 miles north-northwest of Port Hedland, Australia, near 12.0 South latitude and 116.0 East longitude.

Infrared satellite imagery from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite revealed that the low has consolidated during the morning hours, while the Advanced Microwave Scanning Radiometer-E instrument showed deep convection on the north and south sides of the center of circulation. Despite these developments atmospheric dynamics are not currently favorable, so the Joint Typhoon Warning Center currently gives this low a poor chance for development. The second tropical low pressure area NASA satellites are watching is also 500 miles away from land, and that’s System 99S. System 99S is 500 miles north of the Cocos Islands today, near 9.8 South and 99.4 East. The TRMM satellite measured rainfall rates between 5 and 20 millimeters (0.2 and 0.8 inches) per hour within the System 99S early today. The AIRS infrared imagery captured from NASA’s Aqua satellite shows that areas of deep convection exist on all sides of the low pressure center, but it’s not uniform. Vertical wind shear is currently light and sea surface temperatures are warm enough to support development, however, the chance that it will develop into a tropical storm in the next 24 hours is poor. As the week progresses, perhaps the chance will improve with the environmental conditions.

The third tropical low pressure area isn’t a tropical storm but it has triggered a watch for Australia’s Northern Territories. Because of System 91S’ location, about 200 miles northeast of Darwin, Australia (near 10.0 South and 133.1 East), a tropical cyclone Watch has been issued for the coastal communities between Cape Hotham, Port Keats, including Darwin and the Tiwi Islands. The Tiwi Islands include Melville and Bathurst Islands and are part of Australia’s Northern Territory, 25 miles (40 km) north of Darwin where the Arafura Sea joins the Timor Sea. In addition, a Strong Wind Warning has been issued from Milingimbi to Troughton Island.