As a deep freeze grips the nation, there's a celestial signal many of us have overlooked that can predict impending snowfall, and it requires nothing more than a glance upwards on a clear winter's night.
The Science Behind the Lunar Ring
An old piece of weather folklore, 'Ring around the moon, rain soon', holds more scientific truth than you might imagine. The appearance of a moon halo, or lunar halo, is often a precursor to snow. These halos are most visible on cold winter nights when moonlight refracts through ice crystals suspended in a thin, high layer of cloud.
Known scientifically as 22-degree halos due to the specific angle at which the light bends, this atmospheric spectacle generally indicates that snow or rain is on its way, though it is not an absolute guarantee.
What the Meteorologists Say
Senior meteorologist Jonathan Erdman from weather.com advises on what to watch for after spotting the halo. "One thing to look for is whether these thin, wispy cirrus clouds eventually lower and thicken," he said. "If so, then snow or rain is probably on the way."
The next time you see this luminous ring encircling the moon, consider it your cue to have your winter coat ready, prepare for a morning of defrosting the car, or perhaps pack an umbrella. Of course, it's always wise to check the official weather forecast for the most accurate and up-to-date information.
Decoding the Halo's Details
While the halo itself isn't snow, it is a visible sign of the atmospheric conditions that can produce it. The rings are created by two key factors: the presence of ice crystals in high-altitude clouds and the specific atmospheric conditions that allow moisture to rise and freeze.
Adding another layer to this folk wisdom, some believe that the number of stars visible inside the halo can indicate how many days away the bad weather is. Furthermore, one source suggests that the ring's size and clarity can offer a more precise timeline: smaller, well-defined rings might mean snow will arrive within 8 to 12 hours, while larger, fainter rings could signal precipitation in 48 to 72 hours.
On a Quora thread discussing the phenomenon, user Vincent Emery offered a simple comparison. He described a lunar halo as being "essentially the same thing as a rainbow, but instead of the sun you have the moon, instead of rain you have cloud, and instead of an arc you have the full circle!"
