Will Northern Lights Be Back Over MA Skies Friday? Here’s The Latest

MASSACHUSETTS — If you missed the northern lights seen across the country and around the world Thursday night, there may be another chance Friday in Massachusetts.

That's only if the weather cooperates. The National Weather Service forecast for Massachusetts calls for clear skies and a warmer night overall compared to the past few frosty mornings.

The geomagnetic storm that sent the aurora borealis far south Thursday has subsided from a "severe" G4- to a "strong" G3-level storm. The current aurora map from the Space Weather Prediction Center, a division of the National Oceanic and Atmospheric Administration, shows the oval aurora may be seen as far south as northern Iowa.

The aurora could again be visible Saturday in the northern half of Minnesota and other northern-tier states.

On Friday, the SWPC said a K-Index of 7 or greater is expected to persist through Friday. Generally, the K number, a measure of the aurora's strength, needs to be at least 5 for the aurora to be visible.

The amazing display of northern lights Thursday was witnessed by millions of people around the world, including in places such as Cape Town, South Africa. Aurora chasers flooded social media with photos of the pink, red, purple, green and yellow lights.

For only the second time in two decades, NOAA issued a severe geomagnetic storm watch Wednesday after the sun fired off a strong X-class solar flare and coronal mass ejection carried to Earth by exceptionally fast solar winds. CMEs are large explosions of plasma and magnetized particles from the sun's corona that can expand in size as they approach Earth's atmosphere.

The X1-flare that set off this week's display isn't nearly as strong as the X8.7 flare in May that made the aurora visible in areas along the southern U.S. border, or the more recent even stronger X9 flare that produced northern displays in about a third of the country this week.

The difference, space weather forecaster Shawn Dahl explained in a briefing with reporters Wednesday, is that it was a long-duration solar flare that erupted from the center of the sun and is being carried to Earth by extremely fast at 2.5 million miles per hour.