A geomagnetic storm is expected to hit earth just in time for Halloween. That means the aurora should come out to play for the trick-or-treaters, visible dancing overhead if weather cooperates.
A Coronal Mass Ejection (CME) erupted from the sun on Oct. 28, and has been making its way toward Earth. The National Oceanic and Atmospheric Administration says it will reach the planet on Halloween. "Back at the sun, relative calm" defined conditions on Wednesday, NOAA writes.
When the CME reaches earth, it will produce a minor geomagnetic storm, the mellowest of geomagnetic storms. Weak power grid fluctuations can occur, and minor impact on satellite operations are possible. Migratory animals are affected, NOAA writes. And the aurora is often visible as far south as northern Michigan and Maine.
Aurora watching is forecast to be decent on Wednesday as well. The aurora forecast at the University of Alaska Fairbanks Geophysical Institute points to "moderate" aurora displays through Nov. 1, that have been ongoing since Saturday. The NOAA Space Weather Prediction Center in Boulder, Colo., was calling for a 50 percent chance of geomagnetic storming on the Wednesday night and carrying into Thursday.
The aurora borealis dances overhead year-round, but long summer days dim their displays against the sunlit sky. Now, as daylight hours wane, aurora viewing picks back up again.
Yet a cloudy weather forecast in both Anchorage and Fairbanks may obstruct aurora-watchers. In Fairbanks, snow in the forecast may finally bring winter to the Interior city, where an unusually-long autumn has been holding on tight. Anchorage is also forecast to have cloudy skies, as well as rain and snow. But trick-or-treaters may still want to turn their eyes to the skies to catch a glimpse of the displays.