NOAA's GOES-West satellite spotted the eighteenth tropical depression of the Eastern Pacific grow into a tropical storm that was renamed Rachel today, Sept. 25, 2014. Wind shear is affecting the tropical storm, however, so it doesn't have a rounded appearance on satellite imagery.
Tropical Depression 18-E formed on Wednesday, Sept. 24 around 11 a.m. EDT about 285 miles (460 km) south-southwest of Manzanillo, Mexico. Manzanillo is a city in the Manzanillo municipality of the Mexican state of Colima on the country's west coast.
In an infrared image from NOAA's GOES-West satellite on Sept. 25 at 1200 UTC (8 a.m. EDT), Tropical Storm Rachel appeared oval shaped, indicating wind shear was affecting the circulation. The image was created by NASA/NOAA's GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Maryland.
The National Hurricane Center (NHC) noted that microwave data showed Rachel's center was located to the northeast of the deep convection (thunderstorms) due to strong upper-level northeasterly winds.
At 5 a.m. EDT on Thursday, Sept. 25, Rachel's maximum sustained winds were near 40 mph (65 kph) and NHC forecasters expect slight strengthening over the next day or two. Rachel's center was located near latitude 16.0 north and longitude 108.6 west. Rachel was moving toward the west-northwest near 13 mph (20 mph) and that general motion is expected to continue during the next 48 hours.
According to NHC forecasters, Rachel is expected to strengthen a little over the next couple of days before weakening to a depression in four days.
Rob Gutro
NASA's Goddard Space Flight Center