What happens if it’s a cloudy eclipse?

All the talk is about finding clear skies for the Total Solar Eclipse, but there is something unique about experiencing it under cloud

We’re told that Total Solar Eclipses are all about darkness in the day. Actually, they’re not – they’re about Totality. The few minutes when you can stand and stare at the Sun’s mighty white corona are really what it’s all about. But ‘darkness in the day’ is easier to explain that an ethereal, can’t-put-it-into-words spectacle of Totality.

Except that you don’t really get that ‘darkness in the day’ if you stand under the Moon-shadow and have clear skies. That only happens if it’s cloudy. If it’s clear, especially if you have an open view of a big sky, it changes colour as the shadow of the Moon races across you. But it certainly does not get completely dark.

A cloudy eclipse is something to feel, not something to see. It’s just as moving an experience as seeing Totality and, hey, if you’ve never witnessed Totality, you don’t know what you’re missing!

So what happens if it’s a cloudy eclipse? Since millions of Americans will likely miss Totality because of cloud, it’s worth knowing. The truth is, it’s a completely different feeling, which I experienced when I reported on the last cloudy Total Solar Eclipse in the Faroe Islands for the BBC’s Sky At Night magazine:

Here’s an extract from my report:

For those of us who’ve seen totality before, such a near-miss is painful; we know what we, and everyone else is missing. Totality has to be seen, and felt, to be believed – to look at a hole in the sky is unbeatable in its strangeness. Up on Húsareyn, perhaps the most dramatic part of the eclipse was the last fifteen seconds before the end of Totality, when the light levels began to rise rapidly and a silvery, almost black-and-white light spread across the surrounding, jaw-dropping scenery, with the Sun’s light appearing on the expanse of water before us.”

The saddest thing about a clouded-out eclipse is that you miss the partial eclipse and Totality completely, with cloud likely suppressing light levels so much that you won’t notice any changes in light levels until about 30 seconds before Totality. So the build-up is less intense. Then suddenly the light drops quickly like you’ve never witnessed before, like the night is swallowing you up, or like a sunset on fast-forward.

A few minutes of almost total darkness follow. Cameras flash. People take photos … of darkness, of each other, but not of the Sun and Moon. It’s a souvenir photo of something very, very strange. Instead of craning to look at an eclipsed Sun and gasping, whooping (someone always whoops) or fiddling with cameras, people seem to contemplate the event more deeply.

During a cloudy eclipse, the light returns to normal after Totality after only a few seconds. It’s like nothing happened – and that is NOTHING like witnessing, and seeing, Totality in a clear sky.

Where will it be cloudy on 21 August, 2017? That’s anyone’s guess, though the hotspots where eclipse-chasers should be concerned, or completely avoid – and where those after true darkness should head – include mountainous areas like the Great Smoky Mountains in Tennessee, and the coastlines of Oregon and South Carolina.

However, those who meticulously plan to view from areas with a higher chance of clear skies often see nothing, and vice versa, and you will likely be stuck in the location you’ve chosen, whatever the weather, so choose wisely!

Either way, there is a lot to love about a cloudy eclipse – and it’s definitely something worth experiencing … once.

Photo credit: Jamie Carter