Many Americans who gaze skywards this Halloween weekend could be in for a treat.
It's possible the northern lights will be visible over Washington state, the far Northeast and the Upper Midwest thanks to a solar flare and "coronal mass ejection," officials said Friday.
A G3 — or strong — "geomagnetic storm watch" was issued for Saturday and Sunday by the National Oceanic and Atmospheric Administration.
The agency's Space Weather Prediction Center said the coronal mass ejection is expected to reach the Earth on Saturday, and effects are likely to continue into Sunday.
Weather forecasters appeared to be crossing their fingers for clear skies.
Expected conditions in Seattle on Saturday night were called "optimal" for a view of the lights. Much of Montana, too, was forecast to be clear. Forecasters in Gaylord, Michigan, said there would be rain Friday night, but the following night there's a chance to see them.
The National Weather Service in Milwaukee forecast a "possible ghostly green glow" that might be visible as early as 5 p.m. (although the best chance will be later that evening). Minneapolis and St. Paul in Minnesota could see clouds. Even Houston was talking about the northern lights — but the advisory was for those "heading well north."
The aurora borealis, commonly known as the "northern lights" in the Northern Hemisphere, is created when charged particles from the sun interact with the Earth's magnetic field and atmosphere. The aurora borealis is over the north pole, and aurora australis is over the south.
It was about three weeks ago that northern lights were visible in Minnesota, Alaska and Washington, and in parts of Canada due to a G2, or moderate, event.
This weekend's event is not expected to cause technology disruptions, the space weather prediction center said.
The coronal mass ejection happened Thursday around 11:30 a.m. ET, and it left the sun at around 604 miles per second, the center said. NASA said it was an "X1-class flare," and its Solar Dynamics Observatory captured an image of the bright flash.