Northern lights may be visible in 18 states tonight

Several coronal mass ejections (CMEs) are currently hurtling toward Earth. The first expected impact was due in the early hours this morning (March 19) but appears to be running a little late.

Forecasters now say geomagnetic activity is likely to ramp up through March 19-21, with multiple CME impacts expected to trigger minor to moderate (G1 to G2) geomagnetic storms and a chance of stronger (G3) conditions, pushing the northern lights farther south than usual.

NOAA space weather forecasters have issued a G2 (moderate) geomagnetic storm watch for March 19-21 as a combination of incoming CMEs and high-speed solar wind is expected to buffet Earth's magnetic field. While there remains significant uncertainty around the exact timing and strength of the incoming CMEs, forecasters have higher confidence that a coronal high-speed stream will arrive by March 21 — helping sustain geomagnetic storm conditions even if earlier CME impacts are weaker or delayed.

Where can I see the northern lights tonight?

States that could see auroras tonight

Based on the latest NOAA aurora forecast map, the following 18 U.S. states appear fully or partially above the aurora view line:

1. Alaska
2. North Dakota
3. Minnesota
4. Montana
5. Washington
6. Idaho
7. Wisconsin
8. South Dakota
9. Michigan
10. Maine
11. Vermont
12. New Hampshire
13. Oregon
14. Wyoming
15. Iowa
16. Nebraska
17. New York
18. Illinois

But remember, auroras can be relatively unpredictable. The list is based on current forecast data at the time of publication, but if conditions strengthen, northern lights could reach much farther south than expected. Equally, if conditions don't align, we could end up sitting in the dark with no auroras at all. Whether the incoming CMEs deliver impressive aurora shows or end in disappointment largely depends on their magnetic orientation when they hit Earth. If the CME's magnetic field is aligned southward — a component known as Bz — it can link up with Earth's magnetic field, allowing solar energy to stream into our atmosphere and fuel geomagnetic storms. But if it's oriented northward, Earth's magnetic field deflects much of that energy, and the show may never materialize.

Some CME's contain both north- and south-facing fields, which can lead to patchy or fluctuating activity — keeping forecasters and aurora chasers on their toes. We won't know the CME's true magnetic orientation until it's sampled directly by solar wind satellites like DSCOVR and ACE, positioned about a million miles from Earth.

Northern Hemisphere aurora forecast courtesy of the U.K. Met Office

When is the best time to look for the northern lights tonight?

If the skies are clear, make sure to look for the northern lights as soon as it gets dark, as geomagnetic activity will be at elevated levels if the CMEs arrive as predicted. Currently, high geomagnetic activity is forecast to persist all night.

According to NOAA's 3-day forecast, geomagnetic storm activity is expected to be best at the following times:

Even if individual CME impacts are delayed, the arrival of high-speed solar wind later this week means aurora chance could remain elevated into March 21.

How to see the northern lights tonight

If you're in one of the 16 U.S. states where auroras might make an appearance tonight, a little preparation can go a long way toward improving your odds of seeing them.

1. Start by finding a spot with an unobstructed view toward north, preferably somewhere dark and well away from city lights. The clearer your view of the northern horizon, the better.
2. Start scanning the sky with your phone's camera as they are usually good at picking up faint auroral glows that aren't immediately obvious to the naked eye, helping you identify where activity may be starting.
3. Dark adaptation is crucial and often overlooked when aurora chasing. If you can, give your eyes at least 30 minutes to fully adjust to the darkness so you can detect subtle auroral features. Keep in mind that even a quick look at a bright light or phone screen can reset the process, forcing you to start over.
4. Dress for the wait. Aurora shows can be unpredictable and if conditions look promising you may find yourself waiting outside for a while. Make sure to wear plenty of layers!

We recommend downloading a space weather app that provides aurora forecasts based on your location. One option I use is "My Aurora Forecast & Alerts," available for both iOS and Android. However, any similar app should work well. I also use the "Space Weather Live" app, which is available on iOS and Android, to get a deeper understanding of whether the current space weather conditions are favorable for aurora sightings. Want to capture the perfect northern lights photo? Our how to photograph auroras guide can help.

If you snap a photo of the northern or southern lights and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.