The storm has begun!
Earlier this afternoon the first of 6 coronal mass ejections from the Sun reached our planet. As expected, this ignited a severe (G4 class) geomagnetic storm in our atmosphere. Obviously, given this occurred during the daylight hours, no auroras were seen locally. However, this could give us a hint as to what to expect in the next 12-24 hours.
Backing up a bit…
WHAT IS CAUSING THIS…
The sun goes through 11-year cycles of activity, alternating between active and dormant. We are currently smack dab in the middle of an “active phase”, hence, why we see several sunspots on the surface of the Sun.
One of these spots has caught the attention of scientists in recent days. Sunspot AR3664 is absolutely enormous, measuring about the size of 16 Earth’s in diameter!
In the last few days, 6 coronal mass ejections (explosions of solar material, plasma) have burst from this sunspot sending billions of tons of coronal material whizzing through space at more than a million miles per hour. Because this sunspot is currently facing earthward, some of this CME is set to pass through our atmosphere.
Since the Sun is 93 million miles away, it takes a few days for the CME’s to reach Earth.
Well, that time has arrived and the geomagnetic storm has begun.
Predicting the speed, size and intensity of these CME’s is extremely difficult…much harder than forecasting the weather.
Therefore, we cannot really know the exact impact it will have on Earth until it reaches some of our outermost satellites which are located about a million miles from Earth’s surface. This gives us less than an hour’s “heads up” as to the exact magnitude and impact of each wave of CME.
Scientists are typically able to get an initial indication (estimate) almost immediately after the explosion on the Sun’s surface. Using the data they have collected, they are estimating that what we are about to experience will be one of the strongest storms in about 20 years.
Thus far, they have measured a couple of “X class” flares (the highest level of solar flare)…one measuring 2.2 yesterday and another measuring 3.9 earlier this afternoon.
Technically the X scale goes from 1-9 but we have had several X class flares which have measured much higher than 9 in past decades.
SO WHAT DOES THIS ALL MEAN?
Thankfully we do not believe that any of the geomagnetic activity will be intense enough to cause any major electrical grid problems on the Earth’s surface.
This has happened as recently as back in 1989, when a very powerful flare caused a 9 hour blackout in the province of Quebec.
Back in 2003, we had flares intense enough to cause some damage to orbiting satellites and space shuttles.
As of now, it is believed that there has not been a big enough ejection from AR3664 to cause any major communication issues.
WILL WE SEE AN AURORA?
It is an almost certainty that the Northern Lights will be very active overnight tonight through early Saturday.
With geomagnetic values this high, it is likely that there will be auroras sighted all over the United States, perhaps as far south as Texas.
This doesn’t mean everyone will see one though and these events are always highly variable.
In order for us to get a decent shot at seeing anything in southern New England, we typically need the “k index” ( a measure of the level of geomagnetic activity) to be 7 or higher.
You can see that the forecast is for a k index of around 8 overnight tonight.
If you want to optimize your chances to see the Northern Lights, you need to find an area with the least amount of light pollution (dark sky). Also, give yourself a view of as much open sky as possible without any obstructions. Other than that, all I can say is GOOD LUCK. I wouldn’t go out of your way to drive any long distances in an effort to see an aurora tonight. Frankly, there is just as good a shot in your backyard (assuming you live in a dark location) than most other places within driving distance.
WEATHER…THE REAL X FACTOR
The skies won’t be completely clear tonight. There will be lots of clouds around early on, before midnight. The best chance of some clearing would be after midnight and north and west of Boston. Southeastern MA looks like the worst place to be as clouds may linger there most of the night.
So my advice to you…if you are up late, periodically step outside and check the cloud cover…if you have some clearing, take a few minutes and see if you can see anything.
Continue to do so every half hour or so. Auroras can come and go very quickly. What looks amazing one minute could be gone the next.
If you really want to increase your odds, I’d get up real early (or stay up real late) and take a look between midnight and between 4-5am (before some morning light starts to show), this is when there are the greatest odds of clear skies.
Finally, is you are able to snap some pics tonight, we would love to see them! Send them to weather@wbztv.com!
A word of warning…most of the images you see of the Northern Lights online and on TV are using long exposure, very expensive cameras. Seeing an Aurora with the naked eye likely won’t be nearly as vivid or deep in color but, it is still well worth the effort!
Happy viewing!
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