X7.1 solar flare with earth-directed CME

Wednesday, 2 October 2024 02:43 UTC

The X7.1 solar flare which produced a Type II radio sweep was not highly eruptive as you might expect from such an event but it did produce a halo coronal mass ejection with an earth-directed component. We can see this with the help of the SOHO/LASCO coronagraph which shows coronal mass ejections leaving the Sun from Earth's point of view.

However, a majority of the ejecta is heading south-east of our planet with only a faint halo outline directed towards Earth. The NOAA SWPC did issue a strong G3 geomagnetic storm watch for tomorrow, 4 October but it might be a tad on the optimistic side. There is no doubt this cloud will pass Earth, but it's intensity is a bit of a question mark. The same can be said about it's arrival time with the NOAA SWPC's ENLIL model forecasting an arrival time around 10 UTC but in their reports they are rather vague saying there is a small chance the cloud can arrive on the 3rd of 5th of October. That isn't very helpful, however based on the ambient solar wind speed and CME speed it seems it is more likely that the cloud arrives at the tail end of this span, which would be late (European evening) on Friday, 4 October.

The X7.1 solar flare from 1 October produced a faint asymmetrical halo CME that has a high likelihood to arrive at Earth on Friday, 4 October. More information and live data on https://t.co/XHATH0OOfT pic.twitter.com/MjTojqBSTg

— SpaceWeatherLive (@_SpaceWeather_) October 3, 2024