The Philippines have been sitting pretty so far as far as tropical systems are concerned, in fact it has been 178 days since we had our last tropical storm system. That is the 5th longest dry spell on record in the western pacific for time without a named storm.
Even though we do not expect a named storm soon this week the rainy season front to the north will usher in some heavy rainfall in the tropics. What we are seeing is a low pressure area apparently developing in the South China Sea surging in moisture out of the south west monsoon. This is commonly known as the Hagabat in the Philippines and if it is or if it technically isn’t the in the end impacts of heavy rainfall across Luzon will still be the same.
Weather Correspondant Michael Williams wrote about this earlier in his daily update “A developing low latitude extra-tropical low pressure area in the Gulf of Tonkin is going to dry things out a bit over portions of Vietnam, Cambodia and Laos, as the backside of the system’s circulation brings in some slightly drier and more stable air from the north. This drier air will heat up quickly due to the lack of cloud cover, so heat indices will once again approach hazardous levels over portions of interior Indochina this afternoon.
To the east, this developing system will help draw up moisture from the southwest into the Philippines, raising rain chances over the northern third of the archipelago, especially in provinces along the western seaboard. Moisture from the remnants of 93W INVEST will begin to move into the southern Philippines today, raising rain chances there. “
Overall I would continue to expect the heaviest rain from Northern Luzon to Southern Taiwan where the front is at its strongest. Remnant moisture from “93w” the tropical invest area we talked about earlier this week should be limited but not absent in the southern Philippines.
When is TYPHOON Season Most Active?
From Stats taking over the Last 50 Years it is fairly easy to see that Typhoon Season in the Western Pacific really begins to pick up in late summer early autumn. This is the time of year wind shear becomes the most relaxed in the western pacific as the Jet Stream lifts North. Also sea surface temperatures are at there warmest after a full summer has baked the pacific Ocean.
Unlike other basins though you can see in the chart below even in the winter months the risk of Typhoons still persist. Most likely around the Philippines and in to the South China Sea.