The Rainy Season Has Started
20 June 2009 | Davao and Samal, Philippines
Wiskun
As I sit here in the office, I am watching the downpour of rain outside. I am thinking of the floods that I will have to drive through to get to Sasa Ferry terminal. I think I better wait awhile. The rains don't usually last long here. But the rainy season has started and the sailing season in Philippine waters is over.
I have heard on the radio that this is La Nina year - this means more rainfall than normal. For the past weeks, we are certainly experiencing above normal rainfall conditions and even a very early typhoon. This is due to the presence of low pressure areas that are embedded in an active Intertropical Covergence Zone (ITCZ). From the satellite picture above, you can see the band of ITCZ all across Philippines, Indonesia and connecting to the South Pacific Convergence Zone (SPCZ) across Papua New Guinea, Solomons and Vanuatu. Wow, that is certainly a very wide area covered. I wouldn't want to be sailing through this.
According to Pag-asa, "the early migration of the ITCZ is enhancing the southwest windflow over the western and southern parts of the country. The characteristically moist southwest windflow is expected to prevail due to the intensification of the High Pressure Area over Australia especially in the months of July and August. Other rainfall causing systems relative to the Southwest Monsoon such as the ITCZ and tropical cyclones may be modulated by the recession of the North Pacific High Pressure Area and breaks in the rain periods could be expected before the normal peak of the rainy season in July and August. The rainy season will start receding towards the end of August until its normal termination by the end of September."
In Davao, we certainly are affected by the active ITCZ. You can feel the moist and warm southerly wind and this brings rain mostly in the late afternoons or evenings. The ITCZ gives birth to low pressure areas which may turn to typhoons as they migrate north or northwest. When typhoons hit the northern part of the PHilippines, for some reason Davao (Southern Mindanao) usually gets no wind and becomes hot and muggy.
Photo credit: http://www.weather.org/Pacific.htm