A tropical disturbance in the South China Sea has been designated as Invest 90W by the Naval Research Laboratory–the first of the 2016 Western Pacific Season. Although it has been designated as such, currently the Joint Typhoon Warning Center (JTWC) and the Japan Meteorological Agency (JMA) have yet to identify this as a suspect or low pressure area.
Looking at the forecast models, most global models do not develop the area any further that a weak disturbance. The exceptions are the Canadian and the NAVGEM, which develop a weak low pressure area and drift it northward toward southeast China by the end of the week. At this time, it appears that development, if any, will be slow to occur and will be limited. Increased rain showers across the Philippines and southeast China is the main threat, but rainfall totals in these regions appear to be limited to around 50 mm (with locally higher amounts) through the weekend.
One side effect of 90W is the disturbance is increasing rainfall across the Philippines this evening. This comes on the same day as the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) declared the onset of the rainy season. In a statement released by PAGASA, administrator Vicente Manalo said that “the southwest Monsoon was already upon the archipelago.” This will provide relief from the drought conditions affecting portions of the Philippines.