M6.9 solar flare, sunspot regions 2241 and 2242

Thursday, 18 December 2014 22:33 UTC

M6.9 solar flare

Solar activity increased to high levels just moments ago as sunspot region 2241 produced a long duration M6.9 (R2-moderate) solar flare that peaked at 21:58 UTC.

Strong M6.93 solar #flare from #sunspot region 12241 - Follow live on http://t.co/8JIfkaXUPc pic.twitter.com/Ldu322hVFR

— SpaceWeatherLive (@_SpaceWeather_) 18 december 2014

Some darking of the solar corona can be seen following this event which could be a sign that a coronal mass ejection was launched. It is however hard to say how large this coronal mass ejection will be and if it will come towards us. For that we need to wait for coronagraph imagery from SOHO/LASCO which could take a few hours before it is available. We do know that sunspot region 2241 is facing earth right now so it is very much possible that we could see some kind of an earth-directed component should there indeed be a coronal mass ejection associated with this event.

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2014 Dec 18 2155 UTC
NOAA Scale: R2 - Moderate

SUMMARY: 10cm Radio Burst
Begin Time: 2014 Dec 18 2150 UTC
Maximum Time: 2014 Dec 18 2156 UTC
End Time: 2014 Dec 18 2204 UTC
Duration: 14 minutes
Peak Flux: 240 sfu
Latest Penticton Noon Flux: 213 sfu

SUMMARY: X-ray Event exceeded M5
Begin Time: 2014 Dec 18 2141 UTC
Maximum Time: 2014 Dec 18 2158 UTC
End Time: 2014 Dec 18 2225 UTC
X-ray Class: M6.9
Optical Class: 2n
Location: S11E10
NOAA Scale: R2 - Moderate

Comment: Optical class is preliminary.

ALERT: Type II Radio Emission
Begin Time: 2014 Dec 18 2222 UTC
Estimated Velocity: 664 km/s

More information regarding this event will be provided tomorrow (Friday) when SOHO/LASCO coronagraph imagery becomes available. 

Sunspot region 2241

Sunspot region 2241 continued to develop and now has multiple delta structures most notably among the trailing sunspots. There is a decent amount of magnetic mixing and another M-class (R1-R2) solar flare from this sunspot region is likely in the next 24 hours. An X-class event is not impossible.

Sunspot region 2242

Sunspot region 2242 matured and the large areas of opposite polarities seem to be seperating a bit. It still has at least two delta structures of which one is closely packed to an umbra spot of opposite polarites. We can conclude that this sunspot region still has the potential to produce an M-class (R1-R2) event in the next 24 hours with a slight chance that it will produce an X-class (R3) event.

M-class flare probability for the coming 24 hours: 60% chance
X-class flare probability for the coming 24 hours: 20% chance

Solar activity will likely be at moderate to high levels tomorrow. It is worth noting that both sunspot regions are facing earth right now and could launch an earth-directed coronal mass ejection. All the other sunspot regions on the earth-facing disk are unremarkable. Any activity will likely come from sunspot region 2241 or 2242. For all an overview of all the sunspot regions on the earth-facing disk right now please visit this page.

Images: NASA SDO.