Northern Lights Tonight: 19 States May See Aurora Thursday Night

A G2-class geomagnetic storm is possible overnight on Thursday, July 2, through Friday, July 3, potentially bringing displays of the northern lights to northern states along the U.S.-Canadian border. Here’s how to photograph the northern lights with a phone.

The forecast from space weather experts at the National Oceanic and Atmospheric Administration predicts the most activity will occur as it gets dark in North America on Thursday, July 2.

The potential for a display of aurora comes as an Earth-directed, full halo coronal mass ejection — a cloud of charged particles — left the sun late on June 30 in the wake of an X-class solar flare.

It could cause a G2-class geomagnetic storm, which could mean the aurora is seen on the northern horizon in U.S. states close to the border with Canada — most likely across parts of Montana, North Dakota, Minnesota and northern Wisconsin — but potentially much farther south in northern and lower Midwest states.

Long daylight hours in the wake of last week’s solstice, coupled with the light of the waning Strawberry Moon in the south after midnight, may make aurora harder to see.

A G2-rated geomagnetic storm is not a major aurora outbreak forecast, but KP6 conditions — which are predicted — can bring visible northern lights to the far northern tier of the U.S., especially near the Canadian border.

The nine states with the best chance include the northern parts of Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan and Maine. It’s also possible that aurora will be glimpsed from Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, New York, Vermont and New Hampshire.

According to a forecast by space weather experts at the National Oceanic and Atmospheric Administration, “G1-G2 conditions are likely by 03 Jul due to the anticipated arrival of the 30 Jun CME associated with the X1.1 flare,” states NOAA.

A UK Met Office forecast slightly downplays the possibility of strong solar storms. “A coronal mass ejection (CME) arrival is likely to arrive early on the 03 Jul, leading to an increase in potential visible aurora,” states the UK Met Office’s Space Weather forecast.

Space weather can change rapidly, with forecasts revised frequently.

If the skies are clear, aurora watchers should look north, avoid bright lights, and use long-exposure settings on their phones or cameras. Cameras often detect faint aurora before the human eye can see color clearly.

To check visibility in real time, use NOAA’s 30-minute aurora forecast or download apps such as Aurora Now, My Aurora Forecast or Glendale Aurora for up-to-the-minute alerts and live solar wind data.

Whether an aurora display materializes largely depends on the interplanetary magnetic field, specifically its Bz component (you’ll find it in some of the above apps and on SpaceWeatherLive.com). Bz determines how easily solar energy enters Earth’s magnetosphere. When Bz points north, Earth’s field resists it; when Bz swings south, the two fields connect, allowing plasma to stream in. A sustained southward Bz of −5 nT or stronger usually signals an imminent display of aurora.

The northern lights are caused by the solar wind, a constant stream of charged particles flowing from the sun that interacts with Earth’s magnetic field. While most are deflected, some particles spiral along magnetic field lines toward the poles, colliding with oxygen and nitrogen atoms high in the atmosphere. These collisions excite the gases, causing them to release energy as shimmering light.

A CME is a cloud of charged particles often created by solar flares. Unlike solar flares, which travel at the speed of light, CMEs move at up to 1,900 miles (3,000 kilometers) per second and take a few days to travel across the solar system. If they are Earth-directed, they can produce geomagnetic storms and auroras. A "halo CME" is when two CMEs arrive in succession to cause a strong geomagnetic storm.

A mirrorless or DSLR camera is ideal (ISO 1600, 2-10 seconds, f2.8), though newer smartphones are increasingly capable of stunning results. If your smartphone has a Night Mode or Pro Mode, you can capture a beautiful aurora photo with these steps: