GEORGE TOWN: The waterspout that wreaked havoc in three villages in Tanjung Tokong could have been driven by the hot spell in the state, said Universiti Sains Malaysia (USM) School of Physics Deputy Dean Assoc Prof H.S. Lim.
The phenomenon took place over the sea as it was warmer than land during midday.
“Warm and moist air is key to waterspout formation,” he said.
“The warm air that rises rapidly forms lines of towering lower clouds called cumulus clouds.”
Describing the phenomenon as “not normal”, he said the waterspout on Monday was larger and stronger compared to the previous sightings of such phenomenon in Penang.
“This might be due to climate change,” he said.
He added that waterspouts would occur during the transitional season, a change of northeast to southwest monsoon usually around March and April.
Prof Lim said the “rotation” would begin as air converges on the column of rising warm water.
“Although a waterspout is characterised as a tornado, it usually dies out when it travels from water to land. It will lose its energy (warm water).
“The public should avoid waterspouts as it can cause decent damage and kill people when the rotation of warm air is strong,” he said.
USM’s marine biologist Prof Dr Zulfigar Yasin said the size of the waterspout usually depends on the wind force.
“Waterspouts happen randomly ... (However), the probability of a waterspout happening will be higher when there is a thunderstorm.
“A waterspout is formed due to condensation in clouds and it can happen in both ways – from sea to the land and vice versa,” he said yesterday.
Dr Zulfigar advised people to stay indoors when such a phenomenon occurs in the future.
“Do not go outside and stay away from glass windows as it might shatter. Try to keep away from the water.
“If you are out in the open, try to go into a solid shelter or hide behind buildings to stop flying debris from hurting you,” he said.
A waterspout was seen near the UDA low-cost flats near Tanjung Tokong in Penang on Monday.
In the photos and videos that went viral on social media, zinc sheets could be seen swirling mid-air and the waterspout, together with huge sea waves, was heading towards land.
The most recent waterspout was over Penang Bridge in March and October 2017.
However, waterspouts in Penang are weak and dissipate in less than 30 minutes unlike in areas where vast plains meet the sea and waterspouts can reach tornado speeds.
Waterspouts here generally exhibit winds of less than 30m per second, which is around 10 times less violent than tornadoes.
Meanwhile, Malaysian Meteorological Department director-general Datuk Alui Bahari said a waterspout could occur anywhere near the waters in Malaysia.
“It is usually formed during the monsoon transition phase, between April to May and October to November,” he said.
“This is not a first for Penang.”