*Thursday afternoon update*
As mentioned below, a CME hit the Earth late Wednesday evening, but it’s likely that it will not trigger a significant geomagnetic storm. A Geomagnetic Storm Watch remains in effect for tonight, but for a G1 level storm. This means the northern lights may still be visible, but primarily for northern U.S. latitudes near northern Michigan and Maine. Minor disruptions to the power grid are still possible, but not expected. All in all, mid-latitude auroras do not look likely at this time.
*Thursday morning update*
A coronal mass ejection (CME) hit Earth’s magnetic field shortly after 8 p.m. Wednesday evening. As the Earth continues to move through the turbulent wake of this CME, there is a chance for additional geomagnetic storms that would trigger the Northern Lights, i.e., the aurora borealis. According to space weather experts, the impact so far has not triggered a geomagnetic storm. CME-related disturbances are forecast to continue into 11 December resulting in G2 (Moderate) storm levels, and thus, there is another geomagnetic storm watch for tonight. However, confidence in these storms to reach their full potential in creating a small light show for us remains low, but not entirely impossible. Stay tuned!
ROCHESTER, NY (WROC) — CME’s are powerful eruptions of plasma from our sun that can travel through space and have varying impacts on satellites and power grids here on earth.
What does this mean?
Every so often the sun will send out these plasma eruptions, or flares as part of its natural cycle in its own solar magnetic field. Think of these sort of like “sun burps,” and when these eruptions are specifically aimed towards earth, they can generate geomagnetic storms. A particularly strong one of these storms has been forecasted to potentially impact earth over the next few days, which means an aurora, also known as the Northern Lights, could be seen as far south as Chicago, Illinois. It’s possible we may even see it here in Rochester!
What causes this brilliant light show are the charged particles from the sun striking the atoms in the earth’s atmosphere. This interaction between the two releases photons, also known as light particles that create different colors of light depending on the elements they interact with. The most common colors seen in auroras are green, yellow, blue, violet and occasionally pink. We see these colors when these photons of light interact with the 2 most common elements in the atmosphere: nitrogen and oxygen. You get yellow and green light from their interactions with oxygen, and you get red, violet and blue lights from their interactions with nitrogen.
According to the SWPC the initial impact of this geomagnetic storm will rate as a G1 on the space weather scale; not really a big deal. However, they say that if the CME is sustained long enough that a G3 level disturbance, which is a particularly strong event, could occur with peak disturbance on Thursday, December 10th.
Typically, the stronger the geomagnetic storm, the farther south it reaches in the U.S. and the stronger the effects are here on earth. Events at a G3 magnitude do not cause major power outages, but they may cause some disruptions with certain phone carriers and minor radio frequencies. The most exciting impact to see across WNY from this would be the potential to see the northern lights, especially since events like this don’t happen around here all that often.
How likely is this event to play out?
There is still plenty of uncertainty as these types of space storms are notoriously difficult to forecast; much more difficult than it is to predict our chances for rain over the weekend, I can tell you that.
It’s also not as much the ejection of the plasma itself that’s difficult to forecast, but the timing and intensity seen on earth should be taken with a grain of salt. This means that the impacts, if any at all could very well arrive a couple days later than predicted. It can also end up being a lot weaker or even a lot stronger than originally thought. It’s just the nature of these events that makes them so unpredictable. The timing is important too, because if the plasma arrives in the middle of the day, it won’t nearly be as stunning as if it happened at night. Remember that these ejections are coming from the sun way out in space, so when they are projected to be possible, it can be difficult to predict the precise nature of it. But if it does end up playing out, it would be an incredible sight to see.
Bottom line is, if just one piece of the puzzle isn’t aligned right, then we could end up with a whole lot of nothing to look at. That doesn’t mean you should write this off as nothing, but it certainly doesn’t mean you should sacrifice a ton of sleep over it.
If you try to see this thing tonight you’re out of luck. We’re pretty much locked in thick cloud cover until tomorrow, but slightly more ideal conditions are beginning to set up in the weather department for Thursday evening as skies have the potential for some breaks in the night sky. There still may be some clouds around to deal with, but tomorrow looks like the better day to see this if everything lines up the way it should.
Get the latest on the forecast HERE
Also keep in mind the northern light show won’t look exactly like the stunning pictures you see from the arctic circle. You would mainly just be seeing subtle hints of green streaks moving through the sky. Still, a very neat thing to say you’ve witnessed.
The best way to maximize your chances at seeing this will be somewhere with little to no light pollution, and as far north in latitude as you can. You also want to be looking in the northern sky, with the Lake Ontario shoreline being your best bet for both location and avoiding city lights.
~Meteorologist Christine Gregory