How to read the aurora forecast (in Iceland)?

In a recent post, we mentioned how anxious we were to see the aurora borealis during our trip to Iceland. It worked! One of the dreams on our wish list we could already tick off :)

There we also provided a link to two sites that served to help us determine whether there was even a chance of seeing the aurora borealis. However, how to read them correctly? You will find a brief instruction here so that you do not miss anything.

You can find the post about the aurora borealis in Iceland itself here:)

Table of contents

Aurora forecast

Let’s start with the Icelandic Met Office map (available at this link), which is by far the simplest and gives us all the necessary information when it comes to aurora forecasting.

What can be gleaned from the map above is good news for us! There will be a good chance to see the aurora borealis over much of Iceland on Thursday morning! But how to read it?

Cloud cover vs aurora visibility

The colors on the map indicate nothing more than the forecast level of cloud cover. The white field indicates a cloudless sky (according to the scale on the 0/8 map). The brightest green color is a small cloud cover of about 2/8 of the sky. The darkest green, visible on the right side of the map and in the upper left corner, is full cloud cover.

That is, the darker the worse for us. Why? Because the aurora borealis occurs at high altitudes, above the clouds. However, you don’t have to have clear skies to see it. While we were observing the aurora borealis, forecasts said even medium cloud cover, as you can see in our photos. It made it a little difficult, but without exaggeration :)

Of course, as it is with forecasting, anything can change at any time. It’s always a good idea to check the forecast just before dusk to know if it’s worth hunting. This forecast, however, looks very optimistic about clouds.

Auroral activity

Clouds are not everything, however. Great metrologists predict the strength with which the aurora borealis will occur. This, in turn, depends on many factors, mainly, of course, on solar activity.

The above prediction gives us a rating of 3, on a scale of 0-9. Against all odds, this is a very good result. But we’re already explaining…

In general, this scale is, of course, conventional. Whether we are 0 or 9, the chance of seeing the aurora borealis always exists. According to what we were told by the hosts we slept with, the best chance occurs from level 3-4. With 5 on the scale, we’re almost certain to see (barring clouds) the lights of our dreams. The 7-9 scale is very rarely achieved. Nevertheless, it also does not guarantee that we will see the aurora.

Anyway, the aurora is very difficult to hunt. Independent of the score on the scale, the aurora may be visible for only 5 minutes or 5 hours. It may appear just after dark or only in the morning. It can be simply white (the worst) or green, purple or red. It is even rarer for colors to change and ripple.

When is the best chance to see the aurora borealis?

To sum up. If you see 1 on the “Aurora forecast” scale and the sky is totally cloudless, it is already worth hunting for the aurora. It is more the cloudless sky that matters than the scale level. Nevertheless, the bigger it is, the better the chances. We managed to see the aurora with a scale of 3 and medium cloud cover (although we still need to learn to take better photos at night ;-)).

Other forecasts

We also used several Android apps during our trip in Iceland. However, they were no more useful than the above website. Therefore, we will not mention them here.

Worth noting, on the other hand, is this site, which has even more (less and more complicated) information from various sources about the short-term forecast, up to one hour.

In addition to the color indicators showing the current status and short-term forecast of the strength of the aurora borealis, a map with the current probability (live!) of an aurora borealis occurrence is also worth noting and can be accessed directly at: http://www.swpc.noaa.gov/products/aurora-30-minute-forecast

Below you can find its online version:

The graphic above shows the current status!

This map is very intuitive and, most importantly, easy to read. In addition, it shows data virtually online.

Important! This map does not include cloud cover, which you can check on the first page we wrote about.

The redder the color, the greater the chance of seeing the aurora borealis. The red line, on the other hand, determines where the aurora borealis should be visible. Don’t be fooled, however. Even though it should be visible from the right, look around. This was also the case with us hunting for the aurora borealis:)