The National Hurricane Center designated two new systems over the Eastern North Pacific Ocean as tropical cyclones on Thursday afternoon. Tropical Storm Frank was the sixth tropical storm to form over the Eastern North Pacific during the month of July. The record for tropical storms forming in July is seven. If Tropical Depression 08E intensifies into a tropical storm then 2016 will tie the record for the most tropical storms to form over the Eastern Pacific during July.
At 5:00 p.m. EDT on Thursday the center of Tropical Storm Frank was located at latitude 14.9°N and longitude 104.0°W which put it about 675 miles (1085 km) southeast of the southern tip of Baja California. Frank was moving toward the northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1005 mb.
At 5:00 p.m. EDT on Thursday the center of Tropical Depression 08E was located at latitude 10.8°N and longitude 114.0°W which put it about 880 miles (1415 km) south-southwest of the southern tip of Baja California. The depression was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (70 km/h). The minimum surface pressure was 1006 mb.
Tropical Storm Frank is the larger and better organized system. A primary rainband wraps about three-quarters of way around the western side of the center of circulation. Additional rainbands are spiraling around the outer portion of Frank. Thunderstorms near the center of circulation are generating upper level outflow which is pumping out mass in all directions.
The circulation of Tropical Depression 08E is smaller and less well organized. A primary rainband wraps about half way around the western side of the center of circulation. Other partial rainbands are evident, but most of the thunderstorms are occurring in the western half of the circulation. If looks like some of the upper level outflow from Tropical Storm Frank could be causing vertical wind shear over Tropical Depression 08E.
The environment around Tropical Storm Frank is favorable for intensification. Frank is moving over water where the Sea Surface Temperature is near 29°C. In addition, Tropical Storm Frank appears to be located beneath an upper level anticyclone, which is enhancing the upper level divergence. Frank is likely to intensify during the next several days and it could intensify rapidly once an inner core forms around an eye.
The environment around Tropical Depression 08E is not as favorable. It is over water the Sea Surface Temperature is near 28°C. Upper level outflow from the anticyclone over Tropical Storm Frank is generating easterly winds and moderate vertical wind shear over the depression. If Tropical Depression 08E and Tropical Storm Frank move farther apart, then the shear could decrease and the depression could strengthen.
A subtropical ridge is steering both Tropical Storm Frank and Tropical Depression 08E toward the west-northwest. However, a weaker area in the ridge is forecast to develop northwest of Frank and that could allow the tropical storm to move on a more northwesterly track. On its anticipated track Tropical Storm Frank could move near the southern tip of Baja California on Sunday.