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.

In a time series of imagery from NASA’s Aqua satellite, the Atmospheric Infrared Sounder (AIRS) instrument showed Tropical Storm Aere’s progress over the weekend on May 6 at 16:59 UTC, May 7 at 05:29 UTC, and Monday, May 9 at 05:17 UTC. Infrared data basically takes the temperature of a tropical cyclone’s clouds and the coldest areas indicate the strongest thunderstorms and areas of heaviest rainfall. Those coldest cloud temperatures (highest, strongest thunderstorms) and are as cold as or colder than -63F/-52C.

On May 6, when Aere was a tropical depression (03W) it appeared to be more concentrated with the heaviest rainfall and strongest thunderstorms over open ocean. By Saturday, May 7, those heavy rains overspread land areas. On Monday, May 9, the circulation seemed to become weaker and convection seemed to appear more scattered and has decreased in AIRS imagery.

Warnings are still in effect in the Philippines as Aere continues to move north. Public storm warning signal #1 is in effect in the following provinces: Luzon: Quirino, Ifugao, Mt. Province, Kalinga, Apayao and Batanes. Public storm warning signal #2 is in effect for: Luzon: Cagayan, Babuya and Calayan.

The four fatalities caused by Tropical Storm Aere occurred in Balatan, Camarines Sur where a landslide took three lives, and another person drowned in floodwaters in Leyte. Radio reports also noted that nine people at the Manila airport were injured when lightning struck a plane on the tarmac on May 7.