Tropical Storm 27W intensified into a typhoon near Micronesia in the western North Pacific Ocean as NASA's Aqua satellite passed overhead providing visible and infrared data to forecasters.
On Nov. 18 Tropical Storm 27W intensified quickly to typhoon strength. A typhoon warning was posted for Chuuk Lagoon, Losap and Fananu in Chuuk State. A tropical storm warning was posted for Ulul and Lukunor in Chuuk State, and a tropical storm watch was put into effect for Ulul in Chuuk State.
On Nov. 18 at 3:00 UTC (Nov. 17 at 10 p.m. EST), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite captured a visible image of Typhoon In-fa. Although infrared imagery from the Atmospheric Infrared Sounder (that also flies aboard Aqua) showed there is an eye about 10 nautical miles wide, the visible image revealed that it is cloud-filled. The bulk of thunderstorms associated with the typhoon were in the southern quadrant, and there are fragmented bands of thunderstorms in the western quadrant.
At 1500 UTC (10 a.m. EST) on Nov. 18, In-fa was centered near 6.5 degrees north latitude and 154.2 degrees east longitude, about 65 miles north-northeast of Lukunor, 105 miles east-southeast of Losap, 170 miles east-southeast of Chuuk and 275 miles west of Pohnpei.
In-fa had maximum sustained winds near 65 knots (75 mph) and was strengthening. Tropical-storm-force winds extended out to 105 miles from the center. In-fa was moving to the west-northwest at 12 knots (14 mph).
That motion is expected to continue the next few days...with a slight turn to a more westward heading Friday night and Saturday, Nov. 19 and 20. This track takes Typhoon In-fa past Chuuk and Fananu today, Nov. 18.
The Joint Typhoon Warning Center forecast calls for In-fa to continue intensifying as it moves west-northwest through Micronesia and the Marianas.
NOAA's National Weather Service Office in Tiyan, Guam noted that "Stronger trade winds ahead of In-fa will bring scattered showers and isolated thunderstorms along with winds of 15 to 25 mph with gusts to 30 mph to the Mariana Islands over the next couple of days. Stronger winds...heavier showers and thunderstorms associated with In-fa will reach the Marianas as early as Friday night, Nov. 19 and continue into Sunday morning, Nov. 22. Rainfall is expected to be heavy at times...especially Thursday night, Nov. 19 through Saturday night, Nov. 21."
Residents of the Marianas should closely monitor the progress of Typhoon In-fa by keeping up with the latest statements and advisories issued by the national weather service at: http://www.