Tropical Storm Sarika formed east of the Philippines on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Sarika was located at latitude 13.8°N and longitude 127.0°W which put it about 425 miles (685 km) east of Manila, Philippines.  Sarika was moving toward the west at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 997 mb.

The circulation of Tropical Storm Sarika is still organizing.  Most of the thunderstorms are occurring in a broad rainband that curls around the western and southern sides of the circulation.  There are a few thunderstorms in thinner rainbands in the eastern half of the circulation.  More thunderstorms are developing closer to the center of circulation.  Those thunderstorms are beginning to produce upper level divergence which is pumping out mass.  As the mass is removed, the pressure decreases and the wind speeds increase.

Tropical Storm Sarika is moving through an environment that is generally favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge to the north of Sarika is producing easterly winds which are blowing across the top of the tropical storm.  The vertical wind shear may account for the asymmetrical distribution of thunderstorms, but it is not strong enough to prevent Sarika from intensifying.  The vertical wind shear could slow the rate of intensification while the core of the circulation becomes better organized.  Sarika could strengthen into a typhoon with the next 24 to 36 hours.

A subtropical ridge north of Sarika is steering the tropical storm toward the west and that general motion is expected to continue for another 12 to 24 hours.  In a day or so Tropical Storm Sarika is forecast to turn more toward the west-northwest.  On its anticipated track Tropical Storm Sarika could be near Catanduanes Island in about 24 hours.  Sarika could be near Central Luzon in about 48 hours.

Tropical Storm Sarika is expected to intensify into a typhoon.  It could bring strong winds and very heavy rain to parts of the northern Philippines.  The heavy rain could cause flash floods and mudslides.