Forecaster summary - Issued 2024-09-22T00:08:53

High energy flux, as observed by GOES-16 at GEO has been Moderate to High. This is due to the background to slightly elevated solar winds allowing the recent lower orbital level charging, from the CME arrival overnight on 16-17 Sep, to expand outward. While no further notable solar wind enhancements are forecast in the short-term, an overall declining trend is now likely due to natural decay, with flux seeing reduced periods of High and perhaps easing to Background around diurnal minima by Day 2 (23 Sep). Any fast wind onset from CH72/+ later on Day 3 (24 Sep) or during Day 4 (25 Sep) will also help to drop out any remaining flux with flux values expected to fall to Background. 

The associated 24 hour fluence currently remains below the Active threshold, but still retains the potential to rise a little further given the protracted period of High flux during the UTC evening of 21 Sep. However, on the whole fluence values appear to have plateaued, and is considered more likely to remain below the Active level. MOSWOC REFM continues to underestimate the current fluence but does suggest a steeply declining trend through the outlook period, supporting a much reduced likelihood of now reaching the Active level.