(Super Typhoon Ragasa) Former HKO chief warns of window burst risks in specific building corners

As Super Typhoon Ragasa approaches Hong Kong with fierce winds, the risk of glass windows shattering poses a significant threat to homes. 

Former Hong Kong Observatory director Lam Chiu-ying has emphasized the vulnerability of windows at specific building angles, advising residents to keep them tightly sealed during the storm.

Window bursts occur due to extreme pressure differences between indoor and outdoor environments. 

When strong winds hit building corners at an angle, fluid dynamics create intense negative pressure just beyond the corner, exerting an outward force on windows. 

If this force exceeds the glass’s strength, it shatters, sending fragments outward. This effect is often seen in storm videos where curtains are sucked through broken panes, highlighting the pressure imbalance.

Residents should identify windows at these high-risk corner positions and ensure they are securely closed during the typhoon’s peak. 

Vacating rooms with vulnerable windows is critical for safety. If a window breaks, attempting to seal the gap with items like mattresses is highly dangerous. 

The pressure differential can pull a person through the opening, a tragedy reported in past storms in Macau. 

Lam stresses that such actions risk lives, and while property damage is replaceable, human life is not. 

The safest response is to leave the area and wait until the storm subsides.

In cases where multiple windows fail, high-rise residents might find temporary shelter in windowless elevator lobbies, which offer protection from the elements. 

Lam stated that since every home is unique, proactive planning is essential. Residents should develop tailored emergency strategies before the storm intensifies to minimize risks and ensure safety during Super Typhoon Ragasa.