The sky above Florida turned an ominous purple just before the catastrophic Hurricane Milton made landfall on Wednesday evening.
Described as ‘mesmerizing’ and ‘disturbing’ by locals, the first photographs of the phenomenon were taken just hours before the Category 3 storm made landfall.
But purple skies were also seen throughout the state during and after the storm, including Palm Beach, Fort Myers and St. Petersburg.
It may look like a filter, but this rare image is created entirely by nature.
This only happens when atmospheric conditions are just right, and usually coincides with hurricanes or typhoons.
Florida residents have shared photos and videos of unusual, bright purple skies over the state as Hurricane Milton approached
“You don’t necessarily have to have a tropical cyclone to see such a sky, just the right atmospheric conditions to allow for the necessary amount of light scattering,” AccuWeather Meteorologist Brett Rossio said.
The photos show cloudy, electric purple skies glowing at dusk. In some images, the damage from the hurricane stands out against this strikingly beautiful background.
To understand why stormy skies can exhibit this purple hue, it is first important to understand how interactions between atmospheric particles and light create different colors.
The sun emits shortwave radiation on the visible light spectrum – the part of the electromagnetic spectrum that the human eye can see.
When visible light particles reach Earth’s atmosphere, they undergo a process known as Rayleigh scattering.
This is the scattering of light that occurs when radiation particles interact with atmospheric particles much smaller than them.
Shorter wavelengths of light – including blue and purple shades in the visible light spectrum – scatter more easily than longer wavelengths.
“This is why the sky looks blue on a nice sunny day with the sun high in the sky,” Rossio said.
‘Some of the ultraviolet rays reach the surface, leading to sunburn, and the orange, red and yellow colors in the spectrum are of the longwave variety and are not scattered, which is why they appear as visible white light.’
When visible light particles reach Earth’s atmosphere, they undergo a process known as Rayleigh scattering
Shorter wavelengths of light – including blue and purple shades in the visible light spectrum – scatter more easily than longer wavelengths
When the sun sets, the angle at which the light hits the atmosphere changes, causing the color of the sky to change to pink, purple, orange, red and yellow.
But the purple sky seen before Hurricane Milton hit Florida wasn’t caused by the angle of the sun.
This spectacle was actually due to the increased amount of water vapor in the atmosphere as a result of the storm.
More vapor means more particles, and more particles in the atmosphere result in more scattering of light, Rossio explained.
When this scattering occurs around dusk, it can create a pinkish hue that is superimposed on the dark blue sky above.
The increased water vapor in the atmosphere and the timing of Milton’s approach created the perfect conditions to create these purple skies
Not all hurricanes produce purple skies, and trying to predict when one will occur is “trying to predict where a rainbow will appear,” Rossio said.
“If you get the right angle, especially in the evening hours, the pink hue combined with the dark blue sky produces purple,” Rossio said.
“This is often the case when you have low ceilings of stratocumulus clouds overhead in the eastern sky and clear skies in the west,” he added.
Milton isn’t the only hurricane to produce electric purple skies.
Category 1 Hurricane Florence and Category 5 Hurricane Michael, both of which hit the US in 2018, caused this effect.
However, not all hurricanes produce purple skies. Trying to predict when it will happen is “trying to predict where a rainbow will appear,” Rossio said.
But Hurricane Milton rolled in at just the right time to bathe the sky in this unusual color.