Tropical Storm Francisco developed over the Western North Pacific Ocean south of Okinawa on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Francisco was located at latitude 21.2°N and longitude 129.7°E which put the center about 415 miles (670 km) south-southeast of Okinawa.  Francisco was moving toward the northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 996 mb.

A low pressure system over the Western North Pacific Ocean south of Okinawa strengthened on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Francisco.

More thunderstorms formed near the center of Tropical Storm Francisco on Tuesday night.  Thunderstorms were also occurring in bands in the eastern side of Francisco’s circulation.  Bands in the western side of Tropical Storm Francisco consisted primarily of showers and lower clouds.  Storms near the center of Francisco generated upper level divergence that pumped mass away to the east and south of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Francisco was large.  Winds to tropical storm force extended out 185 miles (295 km) from the center of Francisco’s circulation.

Tropical Storm Francisco will move through an environment somewhat favorable for intensification during the next 24 hours.  Francisco will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the eastern side of an upper level low that is centered east of Taiwan.  The upper level low will produce southerly winds that will blow toward the top of Francisco’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Storm Francisco is likely to intensify during the next 24 hours.

Tropical Storm Francisco will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Francisco toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Francisco will move toward the southern Ryukyu Islands.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 11W formed north of Luzon.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Depression 11W was located at latitude 18.5°N and longitude 120.1°E which put the center about 295 miles (470 km) north of Manila, Philippines.  The tropical depression was moving toward the west-southwest 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. (75 km/h).  The minimum surface pressure was 997 mb.