Published on Dec. 8, 2025, 8:19 PM
Check for clear skies in tonight’s forecast, for a chance to see the Northern Lights!
A massive eruption from the Sun over the weekend is fast approaching Earth, and will likely spark displays of the Aurora Borealis across Canada when it arrives, Monday night.
On the afternoon of Saturday, December 6, a strong solar flare exploded from the Sun. Originating from sunspot 4299, which was aimed directly at Earth at the time, it also caused the eruption of a coronal mass ejection out into space, which is currently speeding towards us.
The M8-class flare captured at 20:39 UTC (3:39 p.m. ET) on Dec. 6, 2025, is shown in extreme ultraviolet light by NASA’s Solar Dynamics Observatory (left). The CME that erupted due to this flare (three panels, right), captured by the Solar and Heliospheric Observatory at 3-hour intervals after its eruption. (NASA, NASA/ESA)
Although the brightest portion of the cloud appears to expand away from the eastern limb of the Sun (shown on the right, above), this eruption actually formed a ‘halo CME’, as it expanded away in all directions. This indicates that the resulting solar storm is aimed more or less directly at Earth.
Computer forecast models from NOAA’s Space Weather Prediction Center also show this, along with revealing more details about the structure of the solar storm when it arrives here.
This model run shows the CME arriving early on December 9 (UTC time), formed into a long, stretched-out ribbon at the time. It appears as though the portion that is immediately Earth-effective is lower density than the rest. (NOAA SWPC)
Based on the apparent density of the solar storm, the speed it is travelling, and likely amount of energy the cloud absorbed from the M8-class flare, SWPC forecasters have issued a G3 (strong) geomagnetic storm watch for overnight on Monday, December 8, through Tuesday, December 9.
As of their Monday AM forecast, they are anticipating G1 (minor) geomagnetic storm levels to start off on Monday night. Levels could then ramp up to G2 (moderate) from 03-06 UTC (10 p.m. – 1 a.m. EST), G3 (strong) from 06-09 UTC (1-4 a.m. EST), and may persist at G2 to G3 strength from 09-15 UTC (4-10 a.m. EST).
