By Linggoy Alcuaz
MY FATHER, Manuel “Manolo” Tuazon Alcuaz, taught me most of what I know about Typhoons. They are created by the heat from the Sun interacting with the sea water. Somehow, this makes the air twirl in a Counter Clockwise direction (In the Northern Hemisphere). In the center of the twirling winds, the centrifugal forces create an Eye that is bright and calm because it has no rain and wind.
The same heat from the Sun is what brings (precipitates) the water up to the sky and creates the clouds that give us rain with or without a typhoon or even just a storm. The tail or rear of the Typhoon has more rain and water than its head or front.
In the Western Pacific of the Northern Hemisphere, typhoons generally turn to the Right. The Angle of this right turn increases as they approach Luzon during the “Habagat” or the Monsoon from the South West. Thus, many Typhoons threaten the Philippines but then turn right to the North East and hit China, the Ryuku Islands (Where Okinawa is) and/or Japan.
The tail of a Typhoon that crosses the Philippine Archipelago is at its South East. Thus, we who live in Metro Manila get more rain from a Typhoon that passes to our North even if it is farther away than one that passes to our South. This was true even in the case of Super Typhoon Yolanda who passed over Northern Panay which is nearer to us than the tip of Northern Luzon. Even those that pass through Southern Tagalog give us less rain than those that pass through Central Luzon.
The Usual Typhoon Season almost coincides with the Habagat Season – late May to Early October. Typhoons that visit as in the latter part of an extended Typhoon Season – late October to December, tend to cross the Philippine Archipelago in the Visayas or even as far South as Mindanao. This is due to the Amihan or Monsoon or Winds from the North East which tend to push South Eastward on the Typhoon and prevent it from turning too much to the right and to the North.
The Typhoons are born as Low Pressure Areas far out in the Pacific Ocean towards the West South West. In the Western Atlantic, they are called Hurricanes. In the East Indian Ocean, they are called Cyclones.
While the twirling winds have an average speed of about 150 km per hour near the center, the forward movement of the whole Typhoon is much slower at an average of about 20 km per hour. Thus, a usual Typhoon can travel almost 500 km in a day.
The slower a Typhoon moves forward the more rain it dumps on a particular place. Since Yolanda was faster both in terms of Center Winds and Forward Movement, we were saved from too much rain but took the brunt of double the average Center Winds.
Finally, my Father warned me of the 180 degree Turn (Reverse) in the Direction of the Wind before and after the Typhoon’s Eye passes and the Vacuum Effect of the Lower Pressure in the Eye of the Storm. He always warned us five children to leave small openings in our windows so as to let the higher internal (house) air pressure go out so as to achieve a balance with the lower external air pressure within the Eye of the Storm.
However, since we lived (and still live in) in Quezon City, he did not educate me regarding Storm Surges and Tsunamis. Also, at that time (the 50’s & 60’s), Flooding was hardly known of in Quezon City.
The few Typhoons who’s Eye passed directly over Metro Manila. I believe it struck at the beginning of a long weekend (Friday to Sunday) created by a Typhoon Holiday. Its Front or Head brought very strong winds from the North. After the Eye passed the winds reversed and came from the South. When they did, they fell our Giant Balete Tree in front of our Home on Balete Drive, New Manila, Quezon City. By the end of the weekend my Father was dead.
He had long wanted to cut the Tree because its roots were destroying our water and sewerage pipes. However, my elder siblings begged him not to. And so, he just cut its roots on its South side which is where our House was. He dug a hole in the Adobe along the North West side of our House and poured a solid “Buhos” underground wall. Henceforth, the Balete’s Roots (They are also Vines that come from the branches and take root in the ground and spread out far and wide.) would no longer be able to go beneath our Home like Serpents out to Strangle Us.
And now, fast forward from Yoling to Yolanda.
Yolanda came on Friday, Nov 8, 2013. The day after she bulldozed and cut her way through Eastern, Central and Western Visayas as well as parts of the Mimaropa Region, we (my wife Baby, daughter Cudchie and son Mikko, who still live on Balete Drive but no longer threatened by either a Balete or Rubber Tree.) tried to understand the Storm Surge Phenomenon.
I first heard or read about Storm Surges in relation to the Eastern Seaboard of the USA. The closest I experienced the effects of a Storm Surge was when Wind and Tide combined to cross Roxas Blvd. and flood the basements of several building including the Westin Plaza and the Diamond Hotel. The former is where the Bulong Pulungan is held on Tuesday lunch. The latter is where the former Kapihan sa Manila Hotel of PDI Columnist Neal Cruz is now held on Mondays.
Tacloban and the neighboring towns had a higher and stronger Storm Surge than even the more exposed Southern Towns of Eastern Samar. Yolanda achieved the fastest recorded Center Winds at its first Landfall in Eastern Samar. At subsequent Landfalls in Leyte, Northern Cebu, Northern Panay and Northern Palawan the Velocity of winds near the Center gradually went down. The highest Velocities were probably maintained for the Leyte Landfall because Yolanda’s path was South of the main Samar land mass and mountains.
Since the rotation of the winds was Counter Clockwise, the Higher Storm Surges that swept up (Northwards) the Leyte Gulf must have occurred after the Eye of the Typhoon passed the middle of the Leyte Gulf. Since the Northern part of the Gulf is narrowed by the meeting of Samar and Leyte Islands (Up to the San Juanico Strait), the “Embudo” effect occurred. Eastern Samar, Cebu, Panay and Palawan were spared the “Embudo” effect. However, Ormoc City is inside the South facing Ormoc Bay. This area must have been hit by a lower Storm Surge because by the time the Eye passed over Western Leyte, it had been slowed down by the mountains of Central Leyte. Also, Ormoc Bay is smaller than the Leyte Gulf. Thus, the “Embudo” effect is smaller.
A flashback in History: in October 1944, the US Navy’s Seventh Fleet (much bigger in numbers than today’s Seventh Fleet) defeated the Japanese Imperial Navy in the Battle of Leyte Gulf. Although, the Battles were fought from as far North as off Cape Engano in the North Eastern tip of Cagayan province and as far West as the China Sea off Palawan, as well as in the Sibuyan Sea, the most famous portion is what is called “Crossing the ‘T’ at Surigao Strait”. This was the Classic Dream Sea Battle of Admirals since time immemorial. It was the last time that Surface Fleets would fight it out cannon to cannon with Battleships and Gun Cruisers.
What a Dream Rescue and Relief Mission this must be for today’s US Navy!