(NEXSTAR) — It’s been a busy few weeks on the sun, and yet another eruption of material has been blasted out into space. If conditions are right, it could spark strong G3 geomagnetic storm levels on Earth.
On Saturday, NOAA’s Space Weather Prediction Center (SWPC) noted that an M8.1 solar flare, “an eruption of energy from the sun that generally lasts minutes to hours,” had been detected. Considered “more infrequent,” this flare is weaker than the X-class flares seen in November that led to widespread northern lights viewing in the U.S.
Late last night, the SWPC said a full-halo coronal mass ejection, or CME, associated with the flare had occurred. That CME “is expected to impact Earth early to midday” on Tuesday and, depending on “the orientation of the embedded magnetic field,” it could lead to G3 storm levels.
When CMEs, essentially “sun burbs” of plasma and magnetic material hurled into space, interact with Earth’s atmosphere, they cause geomagnetic storms. The storms are measured on a five-point scale, much like tornadoes.
Last month, G4 storm conditions brought the northern lights into southern stretches of the U.S. that rarely get to see the celestial colors.
G3-strength geomagnetic storms have been known to bring the northern lights as far south as the lower Midwest and Oregon. But, forecasting geomagnetic activity can be difficult until the “burb” is closer to Earth.
The SWPC has issued a strong geomagnetic storm watch for Tuesday. To reach G3 strength, the Kp index, used to measure the magnitude of geomagnetic storms, has to be around 7, according to the SWPC’s scale.
Current forecasting from the SWPC suggests the Kp index could reach such strength at around 4 a.m. EST Tuesday and continue through the day. Strong activity during our daylight hours would mean we can’t see the northern lights, however. If conditions strengthen or change, so too could our chances of seeing the aurora this week.
If you’re hoping to see the northern lights this week, you may have to wait until Tuesday for a complete forecast.
When the northern lights forecast is weaker, it’s often recommended to get as far away from outdoor lights as possible and look northward. Even then, you may only be able to see the northern lights by taking a longer-exposure picture with your phone or a camera.