Forecaster summary - Issued 2025-08-17T00:10:23

GOES high energy (>2MeV) electron flux has become stable about High flux as geomagnetic activity from recent CH71/+ has waned, and is now expected to remain at a similar level until the onset of the next fast wind into the start of the new UTC working week. Active 24-hour fluence is therefore expected to remain until this occurs, whereupon electrons at GEO may fall for a time, probably manifesting in fluence through Tuesday 19 August - given its nature as a 24-hour integrated measure.

The latest MOSWOC REFM is persisting in significantly underplaying the expected forecast, being damped when compared with both persistence and also current observations. Given this poor initialisation and the changes in CH72's expected onset relative to last pass, this inaccurate behaviour is perhaps likely to continue and a continuation of Active fluence is still expected until CH72's onset, whereupon a sharp fall at GEO should occur. The magnitude and timing of any eventual recovery is less certain, but will probably fall outside the scope of this forecast period, perhaps rising later in the coming working week.