Large Solar Flare - X17.2 20031028
Artman40 spotted this and described it as a "very active region." SOHO recorded two flares from this region, an X 17.2 and an X 10.0! http://sohowww.nascom.nasa.gov/hotshots/2003_10_28/ has videos and analysis. In the text it states that the X 17.2 was the second largest flare ever recorded by SOHO.
Solarmonitor for the day (28/10/2003) has this: http://www.solarmonitor.org/full_disk.php?date=20031028&type=smdi_maglc&indexnum=1 (ie no mention of the x17.2 flare) but if you move on to the 29th, the X10.0 flare does rate a mention 😃
It pays to be careful with the timings, it seems, because the image noted by artman40 says "no" to the "major flare in the next 12 hours" flag!
Nice catch artman40 😃
Serendipitously, artman40 came across this same region dated the day before: http://talk.sunspotter.org/#/subjects/ASZ0000433
Interesting to see the changes develop 😃
There has been a ton of research on the events of the 28 Oct-2 Nov 2003 as you can imagine. Just type 'halloween storm' into the search box on http://ads.harvard.edu/
Here is an interesting 'nugget' (a small research project) on comparing two recent sunspot groups to the ones that emerged in 2003: http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/The_Halloween_Flares_and_Large-Scale_Correlations
strange parallels... It could always happen again!