Tropical Storm Kammuri formed on Monday and warnings were issued for the Marianas. At 10:00 p.m. EST on Monday the center of Tropical Storm Kammuri was located at latitude 10.2°N and longitude 149.0°E which put it about 415 miles (665 km) southeast of Guam. Kammuri was moving toward the west-northwest at 16 m.p.h. (26 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.
Tropical Storm Warnings were in effect for Guam, Rota, Tinian and Saipan.
More thunderstorms formed near the center of a large low pressure system southeast of Guam on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Kammuri. The circulation around Kammuri was still organizing on Monday night. Multiple bands of showers and thunderstorms were forming and the bands were starting to revolve around the center of circulation. Storms near the center began to generate upper level divergence which was pumping mass away from the tropical storm in all directions.
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 through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Kammuri will continue to intensify and it could strengthen into a typhoon within 36 hours. Kammuri could eventually intensify into the equivalent of a major hurricane.
Tropical Storm Kammuri will move south of a subtropical high pressure system over the Western North Pacific Ocean during the next two days. The high will steer Kammuri toward the west-northwest. On its anticipated track the center of Tropical Storm Kammuri will pass south of Guam in about 18 to 24 hours. Kammuri could bring gusty winds and locally heavy rain. An upper level trough will approach Tropical Storm Kammuri from the northwest in about 48 hours. The trough will weaken the upper level ridge and the steering currents will weaken. Kammuri could meander after the steering currents weaken.
Elsewhere, over the South Pacific Ocean Tropical Cyclone Rita was weakening northeast of Vanuatu. At 10:00 p.m. EST on Monday the center of Tropical Cyclone Rita was located at latitude 14.3°S and longitude 170.0°E which put it about 265 miles (430 km) north-northeast of Port Vila, Vanuatu. Rita was moving toward the south-southwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 990 mb.