ZAMBOANGA CITY – A freak weather phenomenon rained hailstones on a remote town in the southern Philippine province of Zamboanga Sibugay, but there were no reports of injuries or damages to properties.
It was the second time in almost four decades that hail - the precipitation in the form of pellets composed of ice or of ice and snow, occurring at any time of the year, usually during the passage of a cold front or during a thunderstorm - struck the town of Imelda.
Villagers reported hailstones over the weekend following a heavy rain and thunder and lightning storms, according to the official Philippine Information Agency in Zamboanga City.
Guillermo Dulay, meteorological expert of the Philippine Atmospheric Geophysical Astronomical Administration, said hail can cause damage and injury to crops, livestock, property, and even airplanes.
Dulay said hailstorm was also reported in Baguio City in northern Philippines in 1990 and in South Cotabato and Lanao del Norte in 1999. “The increase in temperature is beyond doubt, as gradual temperature changes were detected as early as 1950’s. Cases of hailstorm in the country are manifestations of global warming.”
“In some case, the effects may already be occurring but difficult to attribute to global warming. But things like backyard tree planting and limiting the use of chlorine and air conditioners, are few of the things each one can do to minimize the global warming impact,” Dulay said.
Small hailstones have a soft center and a single outer coat of ice. They are formed when the surfaces of snow clumps melt and refreeze or become coated with water droplets that subsequently freeze. Large hailstones usually have alternate hard and soft layers.
There are various explanations of how these large stones form and grow. Some believe that they form in clouds when super cooled raindrops freeze on dust particles or snowflakes.
These tiny hailstones are then blown repeatedly up and down by the winds in a cloud. Each time they are blown downward to a region whose temperature is above freezing, the stones collect more moisture, and each time they are blown upward to a region below freezing, the moisture solidifies into ice, and some snow may collect.
The stones continue to grow, adding layer after layer, until they are too heavy to be supported by the winds and fall to the ground. In another explanation, it is suggested that hailstones continuously descend, gaining layers by passing through regions of the air that contain different amounts of water.
Hailstones are spherical or irregularly spherical and usually vary in diameter up to 1/2 in. (1.3 cm); in rare cases hailstones having diameters up to 5 in. (12.7 cm) have been observed.
Just last, during the Earth Day celebration, President Gloria Arroyo called for an action plan of several components to place the Philippines in the front line of the global effort to combat global warming, starting with the incorporation into the public school curriculum of subjects dealing with global warming and climate change. (Mimi Bern-Edaga)