Forecaster summary - Issued 2025-12-23T12:17:55

Suppression in GEO electron counts in the current fast wind has been relatively modest in the past 48 hours, and a rise in the diurnal oscillation becomes increasingly likely into the Christmas period as the chances of further geomagnetic activity and solar wind pressure both ease. This is already in course, with lengthier periods of High flux day-on-day.

Recent MOSWOC REFM runs and persistence methods are both showing a strong rise to surpass Active high energy electron fluence inside the coming 24 hours, with exceedence Expected on Wendnesday 24 December. REFM goes further to suggest a rise to Very Active levels, however this is not borne out in persistence data and is still less likely given that observations are tracking below forecast and persistence at present. All considered, Very Active is rated a rising Slight Chance.