Forecaster summary - Issued 2025-06-08T00:10:21

The greater than 2MeV electron flux observed at GEO by GOES19 has proven volatile through a wide range of values since the beginning of June. The past 24-hour period saw previous High flux fall away at GEO under the effects of the presumed 03 June CME passing Earth. It is as yet unclear as to whether this has redistributed electrons in the Van Allen belts or not - for the time being it is still considered possible for sudden strong recoveries to show at GOES19 as geomagnetic activity wanes. What is clearer is that the threat of Very Active 24-hour fluence now seems unlikely, with the fluence peak prior to the current CME near 4e8 rather than 1e9 or above.

Current CME conditions may continue to deliver enhanced geomagnetic activity to suppress GEO electron fluence at first, however any exceedence of Active becomes Likely into the new UTC week for a time, perhaps again suppressed by any further CME around midweek. MOSWOC REFM is not considered good guidance in the period given the forecast's reliance on transient rather than coronal hole-derived activity.