Tropical Storm Pena moved south of Hawaii on Sunday. At 10:00 p.m. EST on Sunday the center of Tropical Storm Pena was located at latitude 11.4°N and longitude 157.6°W which put the center about 540 miles (870 km) south-southwest of South Point, Hawaii. Pena was moving toward the west at 8 m.p.h. (15 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1002 mb.
Tropical Storm Pena weakened on Sunday as it moved south of Hawaii.
Thunderstorms were still occurring near the center of Tropical Storm Pena. Thunderstorms were also present in bands in the northern and eastern periphery of Pena’s circulation. Bands in the western and southern parts of Tropical Storm Pena consisted primarily of showers and lower clouds. Storms near the center of Pena generated less upper level divergence that pumped less mass away from the tropical storm. The removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere. So, the surface pressure increased on Sunday.
The strongest winds were occurring in the northeastern part of Tropical Storm Pena. Winds to tropical storm force extended out 45 miles (75 km) in the northeastern quadrant of Pena’s circulation. The winds in the other parts of Tropical Storm Pena were blowing at less than tropical storm force.
Tropical Storm Pena will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Pena will move over water where the Sea Surface Temperatures are near 29°C. It will move under the eastern part of an upper level trough that is southwest of Hawaii. The upper level trough will produce southwesterly winds that will blow toward the top of Pena’s circulation. Those upper level winds will cause moderate vertical wind shear. The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification. Tropical Storm Pena could intensify a little during the next 24 hours, if the upper level winds do not get any stronger.
Tropical Storm Pena will move around the southern side of a high pressure system that is over the Central North Pacific Ocean. The high pressure system will steer Pena toward the west during the next 24 hours. On its anticipated track, Tropical Storm Pena will remain far to the south of Hawaii.