NASA's Aqua satellite flew over the Northwestern Pacific Ocean and captured infrared data on newly formed Tropical Depression 30W. The satellite imagery showed that the storm contained some strong thunderstorms around the center of circulation.
The Atmospheric Infrared Sounder or AIRS instrument aboard Aqua provided temperature data on 30W on Dec. 21 at 0353 UTC (Dec. 20 at 10:53 p.m. EST). At the time of the overpass, there was a concentrated area of cold cloud top temperatures (indicating strong thunderstorms) near minus 63 Fahrenheit (minus 53 degrees Celsius) around the center of circulation. There was also a weak banding of thunderstorms north of the center.
The Joint Typhoon Warning Center (JTWC) issued a warning on 30W on Dec. 21 at 10 a.m. EST (1500 UTC). At that time, 30W's maximum sustained winds were near 34.5 mph (30 knots/55.5 kph). The storm was centered near 7.2 degrees north latitude and 140.5 degrees east longitude, about 232 nautical miles southeast of Yap. Tropical Depression 30W is moving to the west-northwest at 9.2 mph (8 knots/14.8 kph).
JTWC's forecast track carries Tropical Depression 30W in a west-northwesterly path and it is expected to intensify to typhoon strength on Dec. 24. The storm is then forecast to track through the north and central Philippines.