Tropical Storm Saola sped toward Tokyo, Japan on Saturday night. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Saola was located at latitude 32.4°N and longitude 134.4°E which put it about 370 miles (595 km) west-southwest of Tokyo. Saola was moving toward the northeast at 24 m.p.h. (39 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 979 mb.
Tropical Storm Saola was weakening and making a transition to an extratropical cyclone. A primary band of showers and thunderstorms wrapped around the eastern side of the circulation. There were other thinner bands of showers revolving around the core of the circulation. Strong westerly winds in the upper levels were causing significant vertical wind shear which was tilting the upper part of the circulation toward the northeast. Cooler drier air appeared to be flowing toward the western part of the circulation.
Westerly winds in the middle latitudes were steering Tropical Storm Saola quickly toward the northeast. The center of Saola will pass south of Shikoku. On its anticipated track the center of Tropical Storm Saola will pass near Tokyo in about 12 hours. Tropical Storm Saola will bring gusty winds and locally heavy rain to Shikoku and central Honshu. The heavy rain could cause flash floods in some locations.
Tropical Storm Saola developed west of Guam on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Saola was located at latitude 14.8°N and longitude 134.8°E which put it about 375 miles (605 km) northwest of Yap. Saola was moving toward the west-northwest at 24 m.p.h. (39 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 997 mb.
The core of the circulation of Tropical Storm Saola became more well organized on Tuesday. The center of circulation strengthened and more thunderstorms developed close to the center Bands of showers and thunderstorms formed outside the core of Tropical Storm Saola. Many of the showers and storms formed southwest of the center. There were fewer showers and storms northeast of the center. The storms near the core of Saola began to produce upper level divergence which was pumping mass away from the tropical storm.
Tropical Storm Saola will move through an environment that will be somewhat favorable for intensification. Saola will move over water where the Sea Surface Temperature is near 30°C. An upper level ridge north of Tropical Storm Saola is producing easterly winds which are blowing toward the top of the circulation. Those winds are causing moderate vertical wind shear which is inhibiting the intensification of Tropical Storm Saola. The upper level winds are forecast to weaken which would cause the wind shear to decrease. The decreased wind shear should allow Tropical Storm Saola to intensify during the next several days and it could eventually strengthen into a typhoon.
The upper level ridge has been steering Tropical Storm Saola toward the west-northwest. An upper level trough east of Asia is forecast to weaken the ridge. When the ridge weakens,Tropical Storm Saola will turn more the north. On its anticipated track Tropical Storm Saola will remain east of the Philippines and Taiwan. Tropical Storm Saola could approach Okinawa in about 72 hours. Saola could be a typhoon when it approaches Okinawa.