Two tropical depressions formed 450 miles apart from each other in the last 24 hours in the Western Pacific Ocean. Tropical Depression 18W (TD18W) is expected to strengthen as it moves towards Guam. Tropical Depression 19W (TD19W) is expected to move through Micronesia, then move northwest toward Taiwan.

Because both storms are close together, forecasting their paths is a challenge because they may interact.

TD 19W was located 235 miles south of Guam, near 9.3 north and 144.1 east during the morning hours (Eastern Daylight Time) on September 28. TD18W was located 630 miles east-southeast of Guam near 9.1 north and 154.8 east. Both had maximum sustained winds near 35 mph.

NASA’s Aqua satellite flew over the TD18W on September 28 at 3:11 UTC (September 27 at 11:11 p.m. EDT) and captured an image of its cloud cover, which appeared disorganized.

Tropical Depression Eight didn’t have much of a lifetime in the far eastern Atlantic Ocean. In fact, it formed after working hours (Eastern Time) on Friday September 25 and faded away about 24 hours later. Tropical depression eight (TD#8) formed on Friday, September 25 at 5 p.m. EDT near latitude 17.4 north and longitude 32.3 west or about 560 miles west of the Cape Verde Islands. TD#8 had maximum sustained winds near 35 mph, and was moving northwest near 14 mph.

The depression experienced 11-17 mph (10-15 knots) of southwesterly vertical wind shear late on Friday night, and those winds increased over the weekend, keeping the storm below tropical storm strength. Adding more challenge to the storm’s development were cooler sea surface temperatures (cooler than the 80F needed to keep it going). Those two factors led to TD#8′s short lifetime.

NASA’s Aqua satellite flew over TD#8 shortly after midnight on September 26, and its Atmospheric Infrared Sounder (AIRS) instrument captured an image of the storm’s cold clouds. The system was not well organized, and didn’t show much strong convection.

By 5 p.m. EDT on Sunday, September 26, TD#8 became a remnant low pressure area near 18.9 north and 35.7 west. Its maximum sustained winds were down to 25 knots (28 mph), and its minimum central pressure was near 1008 millibars. The depression has since officially dissipated.