NASA sees Tropical Depression 29W affected by wind shear
After Tropical Depression 29W formed west of Palau, NASA-NOAA's Suomi NPP satellite captured an image that showed wind shear is affecting the storm.
The Joint Typhoon Warning Center noted that Tropical depression 29W formed on Dec. 16 at 2100 UTC (4 p.m. EST) west of Palau and is not expected to strengthen into a tropical storm. Tropical Depression 29W (TD29W) is known in the Philippines as Onyok.
On Dec. 17 at 4:45 UTC (Dec. 16 at 11:45 p.m. EST) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA's Suomi NPP satellite captured a visible image of Tropical Depression 29W. The VIIRS image showed most of the clouds and thunderstorms were pushed to the west and northwest of the center by wind shear. The center of circulation appeared circled by a thin band of clouds. VIIRS collects visible and infrared imagery and global observations of land, atmosphere, cryosphere and oceans.
At 1500 UTC (10 a.m. EST) on Dec. 17, the Joint Typhoon Warning Center (JWTC) noted that animated enhanced infrared satellite imagery showed the associated clouds and thunderstorms remained sheared (pushed from vertical wind shear) from the low level circulation center that has become difficult to discern. The JTWC did an analysis of the upper level of the troposphere and found the depression is in an area of moderate easterly vertical wind shear (15 to 20 knots/17.2 to 23.0 mph/27.7 to 37.0 kph).
At that time TD29W's maximum sustained winds were near 25 knots (28.7 mpg/46.6 kph). It was centered near 8.4 degrees north latitude and 130.5 east longitude. That's about 527 nautical miles east of Zamboanga, Philippines. TD29W has tracked westward at 5 knots (5.7 mph/9.2 kph) and is expected to continue moving in that general direction toward Mindanao.
The JTWC forecast noted that the system will not intensify much, and is expected to dissipate over Mindanao in the southern Philippines on or around Dec. 19.