The northern lights could become visible across parts of the northern U.S. overnight on Thursday, July 30, through Friday, July 30, with possible glancing blows from two coronal mass ejections on the sun on July 26-27 that are traveling towards Earth. A CME is a cloud of magnetic fields and charged particles from the sun.

NOAA analysts say there is a 25% to 30% chance of a G1-class geomagnetic storm. Such an event could bring aurora into view from northern-tier U.S. states close to the Canada border, though it may be a faint display visible only to those who photograph the northern lights with a phone .

The short summer nights, combined with this week’s full moon , may make faint aurora harder to see. The forecast comes as noctilucent clouds are being seen in the northern hemisphere, a comet brightens and two meteor showers peak — just weeks before a total solar eclipse , for which solar eclipse glasses are required.

Northern Lights Alert For Tonight

According to a forecast by space weather experts at the National Oceanic and Atmospheric Administration, a G1-class geomagnetic storm could begin as it gets dark in North America on Thursday, July 30, with Kp 4 conditions forecast.

“Chances for G1 or greater activity during the forecast period sit at 25-30%, but could become higher depending on both CME trajectory,” states a NOAA forecast discussion . It added that the strength of the glancing blow would potentially make a difference, as would the polarity of the solar wind.

The UK Met Office’s Space Weather Operations Center is forecasting a similar scenario, but is more pessimistic, stating: “Two weak, slow, and faint CMEs may deliver glancing impacts early on Day 1 (30 July), and again late Day 2 (31 July). However, both CMEs are considered more likely to mostly miss Earth.” However, it did add that “active intervals from any CME glance or fast wind enhancement” were possible.

Northern Lights Forecast For The U.S.

All of this suggests a relatively modest space weather event, but enough to give observers across northern-tier U.S. states a chance of seeing the northern lights if skies are clear — and the solar wind’s magnetic field turns southward as it reaches Earth.

A G1 geomagnetic storm can sometimes make the aurora visible from northern U.S. states, particularly from dark locations close to the Canadian border.

Potential viewing areas may include parts of Washington, Idaho, Montana, North Dakota, Minnesota, Wisconsin, Michigan, Maine, Vermont and New Hampshire. However, widespread visibility across the central or southern U.S. is not expected under the current forecast.

Aurora Alert: Solar Wind Conditions

Aurora visibility will ultimately depend on the strength of the solar wind, cloud cover, local light pollution and the orientation of the interplanetary magnetic field. The latter, known as Bz, is one of the most important factors. When Bz points south, it can connect more efficiently with Earth’s magnetic field, allowing energy and charged particles to enter the magnetosphere. A sustained period of southward Bz could make the aurora brighter and push it farther south than expected. If Bz remains northward, however, the resulting display may be weak or restricted to higher latitudes.

Skywatchers should look toward the northern horizon during the darkest part of the night. A location away from streetlights and other sources of light pollution will offer the best chance of seeing faint aurora.

Aurora Alerts: Latest Updates

Aurora forecasts can change quickly after a high-speed solar wind stream reaches Earth. 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.

Smartphone cameras using Night Mode or a long-exposure setting may detect faint green, red or purple aurora before the colors become obvious to the naked eye.

Wishing you clear skies and wide eyes.