A very broad area of low pressure developed enough of the characteristics of a tropical cyclone to be classified as Tropical Storm Omais on Thursday. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Omais was located at latitude 19.5°N and longitude 146.2°E which put it about 380 miles (615 km) north-northeast of Guam. Omais was moving toward the north at 3 m.p.h. (5 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.
The circulation of Tropical Storm Omais is not well organized. Several clusters of thunderstorms exist about 100 miles (160 km) east and south of the center of the very broad low pressure system. No thunderstorms are occurring in the western half of the low or near the center of the circulation. An inner core does not exist at this time and the strongest winds are occurring in the clusters of thunderstorms well removed from the center.
Tropical Storm Omais is in an environment that is favorable for intensification. It is moving over water where the Sea Surface Temperature is near 30°C. The upper level environment is also somewhat favorable for intensification. An upper level low is northwest of Omais and an upper level ridge is east of the tropical storm. Those two features are generating southwesterly winds which are blowing over the top of Tropical Storm Omais. The vertical wind shear is inhibiting the organization and intensification of Omais.
The environment should allow Tropical Storm Omais to intensify, but the large circulation will reduce the rate of intensification. As the wind field contracts and the strongest winds move closer to the center of circulation, the structure of Tropical Storm Omais will move closely resemble a typical tropical cyclone. When an inner core forms at the center of circulation, the rate of intensification may increase.
Tropical Storm Omais is near the western end of a subtropical ridge. The steering currents are weak, but Omais is likely to move slowly toward the north in the short term. A faster motion is expected over the weekend. On its anticipated track Tropical Storm Omais will move near the northernmost Marianas and pass east of Iwo To.