On the morning of November 18, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) issued a notable weather warning.
Accordingly, although no storm is directly active, the combination of many weather patterns is causing rain at the same time. This combination is expected to cause widespread thunderstorms, with the main risk of flash floods and landslides in many places.
This weather phenomenon occurs when the area is in the middle of the transitional season. The northeast monsoon (Amihan) from the north is sweeping down, while the moist weather patterns from the tropics are still active, creating conflict and instability in the atmosphere.
The Intertropical Convergence Zone (ITCZ), a weather pattern familiar to Southeast Asia, is the main cause of rain in the south.
PAGASA forecasts that the ITCZ will cause cloudy skies with scattered showers and thunderstorms in the southern areas of the Philippines. The rest of Mindanao will also see localized showers and thunderstorms due to the influence of this shape.
Meanwhile, in the north, a wind break is active. This is a term for a narrow boundary where two air masses with different temperatures and wind directions (usually the cold air of the monsoon and the hot, tropical air) collide.
The collision also caused strong rain and thunderstorms. The wind shear is expected to affect the northern provinces of Cagayan, Isabela and Apayao, causing scattered showers and thunderstorms.
The Philippine weather agency said that the easterly winds - the continuous flow of moisture from the Pacific Ocean - also contribute to bringing thunderstorms to eastern coastal areas such as the Bicol Region, Aurora and Quezon.
Even Metro Manila and neighboring provinces are affected by the East wind, with forecasts of cloudy skies with scattered showers and thunderstorms.
PAGASA has specifically emphasized the risk of flash floods or landslides occurring in all areas affected by the above three phenomena, as rainfall is forecast to be from moderate to heavy rain. Even in Metro Manila, the risk of flooding and landslides is still possible during strong thunderstorms.
Regarding the situation at sea, winds in the northern and western areas of Northern Luzon, where the northeast monsoon is weak, will blow from medium to strong, causing the sea to be rough to moderate.
The remaining waters of the Philippines, including Mindanao, have light to moderate winds and light to moderate rough seas. Ships need to pay attention to safety warnings when operating at sea.
