CHEYENNE, Wyo. — The National Oceanic and Atmospheric Administration has issued a G4 (severe) geomagnetic storm watch for Oct. 10–11 following a coronal mass ejection, or CME, from the Sun. The CME, which erupted on the evening of Oct. 8, is expected to reach Earth on Oct. 10, potentially bringing strong geomagnetic activity.
A CME is a massive burst of plasma and magnetic fields from the Sun’s corona, traveling at high speeds. This recent CME, moving at 1,200–1,300 kilometers per second, could arrive as early as the morning of Oct. 10. NOAA’s Space Weather Prediction Center, or SWPC, predicts that this event could result in G4 storm levels upon arrival, potentially causing disruptions to communication systems and navigation.
This upcoming storm is of the same severity as the one in May, which produced a stunning display of the northern lights visible across the United States. However, the thick smoke from ongoing wildfires across the state may hinder viewing conditions, potentially obscuring the aurora for some observers.
What to Expect During the Storm
Geomagnetic storms occur when solar wind interacts with Earth’s magnetic field, accelerating electrons along magnetic field lines toward the poles. This interaction can lead to auroras, commonly known as the northern lights in the northern hemisphere. These dazzling light displays are caused when energized electrons collide with atoms in Earth’s upper atmosphere, releasing photons that produce various colors.
Critical infrastructure, including satellite navigation and power grids, could experience disruptions due to the storm’s intensity. The NOAA has advised operators to prepare for potential impacts. Meanwhile, residents can stay informed through the NOAA’s website as more data become available.
Tips for Viewing the Aurora Borealis
Wyoming residents might have a rare opportunity to see the aurora borealis during this geomagnetic event. Here are some tips for getting the best view, courtesy of the SWPC:
- Geomagnetic Activity: Auroral displays depend on the level of geomagnetic activity, measured by the Kp index. Higher Kp values indicate stronger activity and more vibrant auroras extending closer to the equator. For this storm, the Kp index could reach values between 7.67 and 8.33. At this level, the aurora might be visible as far south as Alabama and Northern California.
- Location Matters: Find a place with a clear view to the north, away from city lights. Higher elevations, such as hilltops, offer better vantage points. Even if the aurora appears far north, a clear view can reveal its glow on the horizon.
- Dark Skies Are Key: The best auroral displays are visible in dark conditions. Get away from urban light pollution and avoid viewing during a full moon. This will ensure the aurora’s colors and movements stand out clearly against the night sky.
- Best Times for Viewing: The ideal time to see the aurora is usually between 10 p.m. and 2 a.m. local time. During this geomagnetic event, peak activity might extend beyond midnight due to the high levels of solar wind.
The Science Behind the Lights
Auroras occur when high-speed electrons, accelerated from Earth’s magnetosphere, collide with atmospheric gases. These collisions release energy in the form of light, creating the shimmering curtains of green, red and purple seen in the sky. The green color is most common, produced by oxygen atoms, while rarer red hues come from oxygen at higher altitudes and purples stem from nitrogen, according to the SWPC.
This geomagnetic storm, driven by a fast-moving CME, could make the auroral oval visible over much of the United States, including Wyoming. Auroras are most active around the spring and fall equinoxes due to the way the solar wind interacts with Earth’s magnetic field during these times.
Ongoing Monitoring and Public Guidance
As the CME nears Earth, satellites such as the Deep Space Climate Observatory and the Advanced Composition Explorer will monitor its speed and magnetic properties. This data will offer a better understanding of the storm’s potential impact, helping NOAA adjust its forecasts. Residents in Wyoming should be prepared for possible disruptions while enjoying a rare chance to witness the northern lights.
For more information, visit the NOAA Space Weather Prediction Center’s website.
