Update: 00:30 3/31/2016 GMT (8:30 EST)
SWPC has now issued a G1 geomagnetic storm watch for Saturday April 2nd.
Northern Lights Now – As March draws to a close, there are a couple areas on the Solar disk with notable activity. On Sunday, a stunning solar prominence on the East limb produced a show in SDO imagery. Today, an active region that grew from alpha to beta and is now pointed straight at Earth and located between two coronal holes. Both coronal holes are in negative polarity regions and are related to coronal holes that produced negative Bz and aurora during their previous rotation. It’s possible this could happen again, but likley to a lesser degree on the current rotation.
A solar prominence happens when a large area of gas and charged particles lifts off the Sun into the corona. Prominences are visible in the 304 Angstrom images available on the SDO website. When they happen on the limb they are spectacular, as the dark sky of space acts as a backdrop to the heated gasses lift off the surface. Here’s an animated GIF of images of the prominence as it erupted on Sunday on the east limb over a 12 hour period.
It is unlikely this feature will have any impact on Earth. If it did produce a CME during the eruption, it would be well to the East of the Earth-Sun line.
A Growing Beta Active Region
Active Region 2526 has been increasing in size (from 120MH to 200MH) as it rotates toward center disk. Tonight, SWPC upgraded the magnetic classification from Alpha to Beta. The changes to the region are minor but do increase the probability of flare activity slightly. Thus far, the active region has not produced much flare activity, but keep an eye on it, this could change.
A Pair of Coronal Holes
The most promising solar feature for aurora hunters is the coronal hole that was pointed at Earth yesterday. On it’s previous pass, this coronal hole was a complex of three separate holes and lead to a prolonged period of enhanced solar wind, several periods of south-oriented Bz and a phenomenal display of Aurora. The coronal hole structure has degraded since the last rotation and is now comprised of a pair of medium sized coronal holes. Until today, when the second hole emerged to the NE of the first, this single coronal hole might have produced a short period of elevated solar wind. Now that it is a pair, Earth could experience couple days of slightly elevated soalr wind. Even better news for aurora hunters is that active region 2526 is directly between these two coronal holes, so if it does flare and produce a CME, the plasma will be accelerated by the elevated wind speed. Again, these are worth keeping an eye on the next couple days.