The Northern Lights May Be Visible Over the United States Friday
Thanks to a hole in the sun's atmosphere, there is an aurora watch in effect for March 24.
This weekend will be packed with celestial events, and space fans should just brace themselves.
In addition to the upcoming visible alignment between the moon, Venus, and Mars, the Earth's higher latitudes will likely witness moderate auroras tonight, on Friday, March 24, the US National Oceanic and Atmospheric Administration (NOAA) reports. According to the NOAA's forecast, on March 24 a level 2 geomagnetic storm, which is considered "moderate" according to the NOAA scale, will affect our planet, and moderate auroras are expected because of it.
Specifically, according to tonight's NOAA aurora forecast, some northern states in the contiguous United States might witness the phenomenon, including Washington, Montana, the northern part of South Dakota, Minnesota, Wisconsin, and even the northern tip of Michigan.
The reason behind this geomagnetic storm seems to be an actual "hole" in the sun's atmosphere. There is nothing to worry about, though. Coronal holes are a pretty standard occurrence in the sun's atmosphere, and when they happen, they allow the solar wind to escape faster into space, resulting in stronger winds.
When solar winds are strong enough, they can affect the Earth and influence geomagnetic storms, which then result in moderate-to-strong auroras. Last month, an aurora watch was in place due to a strong geomagnetic storm, and some states in North America were able to witness the phenomenon.
Solar activity and subsequent geomagnetic storms can also bring some interference, including radio blackouts. According to the NOAA, there is currently a slight chance for R1-R2 (minor-moderate) radio blackout risk.
Like it often goes with forecasts, sometimes they can be slightly inaccurate. A few days ago, the NOAA predictions expected Friday to be the beak of the storm in terms of intensity, with a G2 intensity manifesting from 6 pm– 12 am UT. Unexpectedly, though, the geomagnetic storm ended up peaking last night, reaching a G4 intensity, which is considered "strong" on the scale.
Stargazers across the country, in fact, reported gorgeous aurora viewings on Thursday. People as far south as Idaho ended up seeing the lights, and so did some viewers in Wyoming, Wisconsin, Minnesota, Illinois, Iowa, Virginia, and New York. According to AccuWeather, some spotters in Oklahoma and North Carolina reported seeing the northern lights on Thursday evening and early Friday morning as well. Someone on a flight from Los Angeles to Phoenix even reported seeing the aurora on Thursday evening.
How to see the northern lights
The stronger the geomagnetic wind, the higher the chances that you'll be able to see the northern lights. Tonight, according to the NOAA forecast, the storm will have a G2 intensity from 3–6 pm UT.
But a forecast is just a forecast and you still need to be in luck with the weather, though. As an SWPC spokesperson previously told Thrillist, you need clear skies and no structural hindrances (e.g. buildings, trees, or hills) in order to catch a glimpse of the aurora. Plus, it needs to be dark, so dark sites and low-light-pollution areas are what you're looking for. This website allows you to find the nearest dark site, while this map will inform you on light pollution conditions.
You also want to stay as far north as you can, as that will definitely improve your chances. Luckily, you can always plan ahead. To track the aurora's next move and its conditions in real time, you can take a look at the NOAA's 30-minute forecast, which you can find right here. We will also update this story should conditions change drastically as the aurora watch draws closer.