Northern Lights May Be Visible Near Seattle, Detroit, Chicago

SEATTLE — The Northern Lights could dance across the sky in several northern states Monday into Tuesday, from the Pacific Coast to the Midwest and New England.

A massive solar tendril whipped out of the sun Saturday, sending hot plasma hurtling toward the Earth. The National Oceanic and Atmospheric Administration's Space Weather Prediction Center said a G2 moderate geomagnetic storm watch was issued due to a "coronal mass ejection," or CME, seen originating from a large filament eruption over the weekend.

"An Earth-directed component to the CME is likely with an arrival early on 19 Sep (UTC)," the agency said, adding that should the CME arrive as expected, "g2 levels are likely."

This means the Northern Lights could be visible much more than usual.

NOAA's "view line" showed the Aurora Borealis could be visible Late Monday and early Tuesday in Seattle, Chicago, Minneapolis, Detroit, Milwaukee, Des Moines, Rochester, Buffalo, Portsmouth, Portland (Maine) and more.

Experts at the University of Alaska - Fairbanks Geophysical Institute, expect a KP index of 6. In general, the chances of seeing the northern flights are best with a Kp index of at least 5.

Aurora forecasts are notoriously tricky and can quickly change. Anytime the northern lights are active, the best times to see auroras are between 10 p.m. and 2 a.m., according to the Space Weather Prediction Center. Get away from city lights for the best viewing opportunities. A waning crescent moon at less than 50 percent illumination will help aurora hunters on Thursday.

"Weather permitting, highly active auroral displays will be visible overhead from Inuvik, Yellowknife, Rankin and Iqaluit to Vancouver, Helena, Minneapolis, Milwaukee, Bay City, Toronto, Montpelier, and Charlottetown, and visible low on the horizon from Salem, Boise, Cheyenne, Lincoln, Indianapolis and Annapolis, the institute said in its Tuesday night forecast.

Keith Strong, a solar physicist, tweeted over the weekend that a "monster eruption" was forecast to hit the Earth on the 19th with solar wind speeds of 500 km per second.

"Fortunately, the CME mostly passes ahead of the Earth," he said.

On Saturday, Strong called it: "THE BIGGEST ERUPTION I HAVE EVER SEEN!"

"I have been observing the Sun professionally for over 50 years and this is the largest filament eruption I have seen," he tweeted. "Note it covers over half the Sun, compare it to the size of the Earth (inset) but amazingly it did not produce a big flare."