Tropical Storm Kammuri Passes South of Guam

Tropical Storm Kammuri passed south of Guam on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kammuri was located at latitude 11.8°N and longitude 141.8°E which put it about 225 miles (365 km) southwest of Guam.  Kammuri was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 985 mb.  The Tropical Storm Warnings for Guam, Rota, Saipan and Tinian were discontinued.

The circulation around Tropical Storm Kammuri exhibited greater organization on Tuesday.  Rainbands around the center of circulation were more circular.  Storms near the center were generating upper level divergence which was pumping mass away to the north and west of the tropical storm.  There were also more thunderstorms in bands north and west of the center of Kammuri.  Bands southeast of the center consisted primarily of showers and lower clouds.  The wind field around Tropical Storm Kammuri was also asymmetrical.  Winds to tropical storm force extended out farther in the northern half of the circulation.  Winds to tropical storm force extended out 240 miles (340 km) to the northeast of the center of Kammuri.  In contrast, tropical storm force winds only extended out 75 miles (120 km) to the southeast of the center of circulation.

Tropical Storm Kammuri will move through an environment favorable for intensification during the next few days.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  The shear will slow the rate of intensification, but it will not be strong enough to prevent Tropical Storm Kammuri from getting stronger.  Kammuri is likely to intensify into a typhoon during the next 24 hours and it could strengthen into the equivalent of a major hurricane later this week.

Tropical Storm Kammuri will move around the western end of a subtropical high pressure system over the Western Pacific Ocean during the next 48 to 72 hours.  The ridge will steer Kammuri toward the northwest.  A second high pressure system will move eastward from Asia in about three days.  The second high will block Tropical Storm Kammuri from moving any farther toward the north and the high will steer Kammuri toward the west during the weekend.  On its anticipated track Tropical Storm Kammuri will gradually move closer to the Philippines.

Elsewhere, over the South Pacific Ocean near Vanuatu vertical wind shear weakened Tropical Cyclone Rita.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Rita was located at latitude 15.3°S and longitude 169.0°E which put it about 180 miles (290 km) north of Port Vila, Vanuatu.  Rita was moving toward the south at 5 m.p.h. (8 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 1000 mb.