Strong thunderstorms around the center of circulation in tropical low pressure System 98W were seen on infrared satellite imagery and were a clue to forecasters that the storm was intensifying. Early on Sept. 24, the storm intensified into Tropical Depression Kammuri far north of Guam.
NASA's Aqua satellite passed over Tropical Depression Kammuri on Sept. 24 at 12:23 a.m. EDT. Kammuri is a large storm and strong thunderstorms covered a long area within the somewhat elongated circulation. The circulation center was near the western edge of the massive extent of clouds. The Atmospheric Infrared Sounder or AIRS instrument that flies aboard Aqua gathered infrared temperature data on the storm's clouds. The data was false-colored at NASA's Jet Propulsion Laboratory, Pasadena, California. The strongest thunderstorms had cloud-top temperatures near -63F/-53C reaching high into the troposphere (lowest layer of the atmosphere) and with the potential to generate heavy rain.
The Joint Typhoon Warning Center bulleting on Sept. 24 at 1500 UTC (11 a.m. EDT) noted that Kammuri had maximum sustained winds near 30 knots (34.5 mph/55.5 kph). It was centered about 320 miles northeast of Saipan, near 19.3 north latitude and 149.3 east longitude. At the time, the depression had It was moving to the north-northwestward at 4 knots (4.6 mph/7.4 kph).
Forecasters at the Joint Typhoon Warning Center expect Kammuri to intensify into a typhoon and move to the north-northwest passing near the island of Iwo To on Sept. 27.
NASA's Goddard Space Flight Center