HALIFAX -- An eerie high-pitched howl that croons from an under-construction convention centre during high winds is turning heads in Halifax, but a local meteorologist says the phenomenon is not unusual.
Social media has been abuzz about the unearthly keening at the Nova Centre in the downtown core, sparking the hashtag .HalifaxHowl and drawing comparisons to a banshee -- a wailing female spirit that warns of death.
"You guys weren't kidding about that crazy Nova Centre wind sound. Like a banshee siren sending shivers through the spine of the city," said a Twitter user posting under the name Ryan McNutt.
"If you haven't heard the .HalifaxHowl yet, you'll be amazed. Such a crazy sound!" tweeted another Twitter user identified as Marc Almon.
But local meteorologist Richard Zurawski said the phenomenon is not uncommon and can be heard in many structures, such as suspension bridges.
Zurawski said if winds pass through the unfinished structure at the right speed, intensity and wave length, it creates standing waves.
"It's very similar to a musical instrument," said Zurawski in a phone interview on Saturday.
"Think of it almost as wind chimes in a way. They're not banging against each other but they are setting up standing waves. It's these standing waves that we're hearing and they can be very eerie because what we're hearing are different harmonics."
On Saturday afternoon, the piercing shrill could be heard throughout the streets of downtown Halifax as the remaining winds from a nor'easter gusted up to 70 kilometres an hour.
Zurawski says once the Nova Centre -- which has many windows left to be installed -- is complete, the haunting howl will stop.
"In the middle of the construction period, you've got places for the wind to go through," said Zurawski. "But once the building is complete, you won't be hearing this anymore."
