Forecaster summary - Issued 2025-10-21T00:11:44

The >2MeV electron flux recorded at GOES19 has been on a very flat trend at moderate levels, with little sign of the usual diurnal pattern. Persistence would have electron flux gradually rising to high diurnal peaks over the next four days, but overall probably falling short of Active 24-hour integrated fluence. However, the difference from previous rotation is that there has been some CME contribution over the past weekend, with uncertain influence in charging or redistributing electrons within the Van Allen belts. All considered, the trend in fluence should soon be upward, with a chance of Active fluence as the fast wind from CH87/- matures. MOSWOC REFM is suggesting Active fluence could be reached during Day 2 (22 Oct), however it does tend to over-estimate fluence levels during the waning phase of a HSS.